Guidance on

Geologic Monitoring for Vital Indicators

**National Park Service**

**Geologic Resources Division**

**July 30, 2000 Draft**

# Introduction

**Geologic monitoring can be used to detect long term environmental
change, provide insights into the ecological consequences of those
changes and to help determine if the observed changes dictate a
corrective action in management practices. Geologic indicators can be
used to assess whether environmental change is within a normal or
anticipated range of variation. Geologic indicators include measurements
of change in volcano activity, earth movement, glacier advance and
retreat, shoreline movement, sand dune movement or mobilization,
sediment storage and loading, soil erosion, thermal feature activity and
temperature change, and slope and rock stability, among others.**

Linkage

**Geologic monitoring activities can be linked to existing laws,
regulations, agency strategies, and planning processes. The overarching
drivers are the NPS Organic Act, the Government Performance and Results
Act (GPRA), and the 1998 NPS Omnibus Act. Resource-specific geology
legislation includes the Federal Cave Resources Protection Act (1988),
Coastal Barrier Resource Protection Act (1982), Geothermal Steam Act
(1970), and Wild and Scenic Rivers Act (1968).**

**In addition, park enabling legislations often address specific
direction for geologic resources management. Over 160 parks have
significant geologic resources and 83 parks exist because of a geologic
theme. NPS Management Policies, Director's Orders and initiatives (such
as the Coral Reefs Initiative) can also provide guidance for monitoring
of geologic features and processes. Geologic monitoring should be
addressed in a park's General Management Plan (GMP), Resource Management
Plan (RMP) and possibly in the Visitor Experience and Resource
Protection Plan (VERP).**

Why is Monitoring of the Physical Component of the Ecosystem Important?

![](media/image1.jpeg){width="3.359722222222222in"
height="3.073611111111111in"}**It is unrealistic to attempt an
evaluation of ecosystem function without considering the landscape and
earth systems. Biological systems depend upon and interact with abiotic
components. Without water, soil, rock, and atmospheric components, we
are ignoring critical parts of the ecosystem. Physical systems can be
bellwethers of significant ecosystem change. Changes in physical systems
can have significant impacts on human health and safety and human
activities can, in turn, force changes in physical systems.**

## Effective resource management is based on understanding the ecosystem, not just one or several of its component parts. In developing an ecosystem study model for science-based management, it is important to consider the contributions of social, physical and biological sciences. Monitoring the physical component provides important information on the complex interactions that take place with the ecosystem.

What Physical Components of the Ecosystem need to be Monitored?

**The physical component of the ecosystem is comprised of three basic
parts, geology, hydrology and meteorology. Within these disciplines,
changes in the ecosystem can be observed through measurements of the
magnitudes, frequencies, rates, and trends of physical processes.
Measurements that are particularly useful as indicators for detecting
ecosystem change include processes occurring at or near the Earth's
surface and those subject to change over periods of 100 years or less.
The Commission on Geologic Science developed a list of these
\"geoindicators\" during a three-year international project for
Environmental Planning (International Union of Geological Sciences). For
the purpose of evaluating NPS geologic monitoring needs within parks and
networks, we have chosen to use Geoindicators as an assessment tool. On
the following page is a checklist of the 27 geoindicators. The entire
list is included, but the Geologic Resources Division will only be
responsible for the 18 geologic indicators, shown with an asterisk.**

+----------------------------+---------+---------+--------+-----------+
| GEOINDICATOR               | Imp     | Natural | Human  | Unde      |
|                            | ortance |         |        | rstanding |
|                            | for     | In      | Inf    |           |
|                            | this    | fluence | luence | Past      |
|                            | Park    |         |        |           |
|                            |         |         |        | Env       |
|                            |         |         |        | ironments |
+----------------------------+---------+---------+--------+-----------+
| # Alpine and polar         |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Frozen ground          |         | **H**   | **M**  | **H**     |
| activity**                 |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Glacier fluctuations** |         | **H**   | **L**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| # Arid and Semi-arid       |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Desert biotic crusts   |         | **H**   | **H**  | **M**     |
| and pavements**            |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Dune formation and     |         | **H**   | **H**  | **M**     |
| reactivation**             |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Wind erosion**         |         | **H**   | **M**  | **M**     |
+----------------------------+---------+---------+--------+-----------+
| **Dust storm magnitude,    |         | **H**   | **H**  | **M**     |
| duration and frequency**   |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Coastal**                |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Coral chemistry and      |         | **H**   | **H**  | **H**     |
| growth patterns**          |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Relative sea level**   |         | **H**   | **M**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Shoreline position**   |         | **H**   | **H**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| # Groundwater-related      |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Groundwater chemistry in |         | **H**   | **H**  | **H**     |
| the unsaturated zone**     |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Groundwater level**      |         | **M**   | **H**  | **L**     |
+----------------------------+---------+---------+--------+-----------+
| **Groundwater quality**    |         | **M**   | **H**  | **L**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Karst activity**       |         | **H**   | **M**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| # Surface water            |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Lake levels and          |         | **H**   | **H**  | **M**     |
| salinity**                 |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Surface water quality**  |         | **H**   | **H**  | **L**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Stream channel         |         | **H**   | **H**  | **L**     |
| morphology**               |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Streamflow**             |         | **H**   | **H**  | **L**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Stream sediment        |         | **H**   | **H**  | **M**     |
| storage and load**         |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Wetlands extent,         |         | **H**   | **H**  | **H**     |
| structure, and hydrology** |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| # Hazards                  |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Volcanic unrest**      |         | **H**   | **L**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Seismicity**           |         | **H**   | **M**  | **L**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Slope failure          |         | **H**   | **H**  | **M**     |
| (landslides)**             |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **Other (multiple          |         |         |        |           |
| environment)**             |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Soil and sediment      |         | **H**   | **H**  | **M**     |
| erosion**                  |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Soil quality**         |         | **M**   | **H**  | **H**     |
+----------------------------+---------+---------+--------+-----------+
| **\*Subsurface temperature |         | **H**   | **M**  | **H**     |
| regime**                   |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Sediment sequence and  |         | **H**   | **H**  | **H**     |
| composition**              |         |         |        |           |
+----------------------------+---------+---------+--------+-----------+
| **\*Surface displacement** |         | **H**   | **M**  | **M**     |
+----------------------------+---------+---------+--------+-----------+

# 

# \* - Geologic indicators

# H - HIGHLY influenced by, or with important utility for

# M - MODERATELY influenced by, or have some utility for

**L - LOW or no substantial influence on, or utility for**

#  

# Use of Geoindicators as a Tool

Geoindicators have been developed as tools to assist in an integrated
assessment of natural ecosystems. Working with geologic specialists,
monitoring networks can use the geoindicator checklist and the 18
geologic monitoring parameters (see appendices) to ensure adequate
planning for the monitoring of geoindicators. Preliminary assessment of
which geoindicators to include as vital indicators for parks or networks
should be accomplished during the workshop using the groups knowledge of
the resource and the information in the geologic monitoring parameters.
The following is a brief description of the significance of each
geoindicator:

**\*[Frozen ground activity]{.underline}: Permafrost influences natural
and managed ecosystems, including forests, grasslands and rangelands,
mountains and wetlands, and their hydrological systems. It is an agent
of environmental change that affects ecosystems and human settlements.
Permafrost may enhance further climate change by the release of carbon
and other greenhouse gases during thawing. It is estimated that nearly
1/4 of the world\'s terrestrial carbon is tied up in dead organic mater
in the active layer and in permafrost: long-term climate warming would
facilitate decomposition and drying, releasing huge quantities of
methane and CO2 \[see wetlands extent, structure and hydrology\].
Permafrost can result in serious and costly disruptions from ground
subsidence, slope failure, icings, and other cryogenic processes.**

### \*Glacier fluctuations: Glaciers are highly sensitive, natural, large-scale, representative indicators of the energy balance at the Earth\'s surface in polar regions and high-altitudes. Their capacity to store water for extended periods exerts significant control on the surface water cycle. The advance and retreat of mountain glaciers creates hazards to nearby human structures and communities through avalanches, slope failure, catastrophic outburst floods from ice and moraine-dammed lakes. Notwithstanding local glacier advances, the length of mountain glaciers and their ice volume has decreased throughout the world during the past century or two, providing strong evidence for climate warming, though there may also be local correlations with decreasing precipitation. It is estimated that the European Alps have lost more than half their ice in the past century

\*[Desert biotic crusts and pavements]{.underline}: Desert surface
crusts are important because they protect the underlying fine material
from wind erosion.

\*[Dune formation and reactivation]{.underline}: Moving dunes may engulf
houses, fields, settlements and transportation corridors. They also
provide a good index of changes in aridity. Coastal dunes are important
determinants of coastal stability, supplying, storing and receiving sand
blown from adjacent beaches. Dunes play an important role in many
ecosystems (boreal, semi-arid, desert, coastal) by providing
morphological and hydrological controls on biological gradients.

**\*[Wind erosion]{.underline}: Changes in wind-shaped surface
morphology and vegetation cover that accompany desertification, drought,
and aridification are important gauges of environmental change in arid
lands. Wind erosion also affects arid and semi-arid regions, by removing
topsoil, seeds and nutrients.**

[Dust storm magnitude, duration, and frequency]{.underline}: Local,
regional and global weather patterns can be strongly influenced by
accumulations of dust in the atmosphere. Dust storms remove large
quantities of surface sediments and topsoil with nutrients and seeds.
Wind-borne dust, especially where the grain size is less than 10 µm, and
salts are known hazards to human health. Dust storms are also an
important source of nutrients for soils in desert margin areas.

[Coral chemistry and growth patterns]{.underline}: The combination of
abundant geochemical tracers, sub-annual time resolution, near-perfect
dating capacity, and applicability to both current and past climatic
changes establishes corals as one of the richest natural environmental
recorders and archives. A 30 cm-diameter coral colony growing at an
average rate of 1 cm/yr will provide 20-25 years of baseline data,
whereas massive colonies 3-6 m high may provide historical data for
extensive tracts of tropical ocean, such as are not otherwise available.

### Relative sea level: Changes in RSL may alter the position and morphology of coastlines, causing coastal flooding, waterlogging of soils and a loss or gain of land. They may also create or destroy coastal wetlands and salt marshes, inundate coastal settlements, and induce salt-water intrusion into aquifers, leading to salinization of groundwater. Coastal ecosystems are affected, for example, by increased salt stress on plants. A changing RSL may also have profound effects on coastal structures and communities. Low-lying coastal and island parks are particularly susceptible to sea-level rise. It is estimated that 70% of the world\'s sandy beaches are affected by coastal erosion induced by RSL rise.

### \*Shoreline position: Changes in the position of the shoreline affect transportation routes, coastal installations, communities, and ecosystems. The effects of shoreline erosion on coastal communities and structures can be drastic and costly. It is of paramount importance for coastal parks to know if local shorelines are advancing, retreating or stable. Rates of recession as high as 5-10 m/yr have been measured in many places around the world, and much higher rates have been recorded locally. Coastal erosion in the USA alone is estimated to cost \$700 million annually. 

### Groundwater chemistry in the unsaturated zone: Changes in recharge rates have a direct relationship to water resource availability. The unsaturated zone may store and transmit pollutants, the release of which may have a sudden adverse impact on groundwater quality.

### Groundwater level: Groundwater is the major source of water in many regions. In the USA, more than half the drinking water comes from the subsurface: in arid regions it is generally the only source of water. The availability of clean water is of fundamental importance to the sustainability of life. It is essential to know how long the resource will last and to determine the present recharge: groundwater mining is a terminal condition.

### Groundwater quality: Groundwater is important for human consumption, and changes in quality can have serious consequences. It is also important for the support of habitat and for maintaining the quality of baseflow to rivers. The chemical composition of groundwater is a measure of its suitability as a source of water for human and animal consumption, irrigation, and for industrial and other purposes. It also influences ecosystem health and function. It is important to detect change and early warnings of change both in natural systems and resulting from pollution.

### \*Karst activity: It is estimated that karst landscapes occupy up to 10% of the Earth\'s land surface, and that as much as a quarter of the world\'s population is supplied by karst water. The karst system is sensitive to many environmental factors. The presence and growth of caves may cause short-term problems, including bedrock collapse, disparities in well yields, poor groundwater quality because of lack of filtering action, and instability of overlying soils.

**[Lake levels and salinity]{.underline}: The history of fluctuations in
lake levels provides a detailed record of climate changes on a scale of
ten to a million years. Lakes can also be valuable indicators of
near-surface groundwater conditions.**

### Surface water quality: Clean water is essential to human survival as well as to aquatic life. Pathogens such as bacteria, viruses and parasites can make polluted waters among the world\'s most dangerous environmental problems. Water quality data are essential for the implementation of responsible water quality management, for characterizing and remediating contamination, and for the protection of the health of humans and aquatic organisms.

### \*Stream channel morphology: Channel dimensions reflect magnitude of water and sediment discharges. An understanding of stream morphology can help delineate environmental changes of many kinds. Changes in stream pattern, which can be very rapid in arid and semi-arid areas, can limit land use and alter habitat, such as on islands in braided streams and meander plains, or along banks undergoing erosion.

### Streamflow: Streamflow directly reflects climatic variation. Changes in streams and streamflow are indicators of changes in basin dynamics and land use.

### \*Stream sediment storage and load: Sediment load determines channel shape and pattern \[see stream channel morphology\]. Changes in sediment yield reflect changes in basin conditions, including climate, soils, erosion rates, vegetation, topography and land use. Fluctuations in sediment discharge affect many terrestrial and coastal processes, including ecosystem responses, because nutrients are transported together with the sediment load. Stream deposits also represent huge potential sinks for, and sources of, contaminants.

### Wetlands extent, structure and hydrology: Wetlands are areas of high biological productivity and diversity. They provide important sites for wildlife habitat and human recreation. Wetlands mediate large and small-scale environmental processes by altering downstream catchments. Wetlands can affect local hydrology by acting as a filter, sequestering and storing heavy metals and other pollutants, such as Hg, and serving as flood buffers and, in coastal zones, as storm defenses and erosion controls. 

### \*Volcanic unrest: Natural hazards associated with eruptions of the world\'s 550 or so historically active volcanoes pose a significant threat to about 10% of the world\'s population, especially in densely-populated circum-Pacific regions. By the year 2000, more than half a billion people will be at risk. 

**\*[Seismicity]{.underline}: Earthquakes constitute one of the greatest
natural hazards to human society. Between 1960 and 1990 earthquakes
killed about 439,000 people worldwide and caused an overall economic
loss of some \$ 65 billion. Surface effects include uplift or
subsidence, surface faulting, landslides and debris flows, liquefaction,
ground shaking, and tsunamis ('tidal' waves caused by undersea tremors).
Damage to buildings, roads, sewers, gas and water lines, power and
telephone systems, and other built structures commonly occurs.**

\*[Slope failure (landslides)]{.underline}: Annual property damage from
landslides worldwide is estimated in the tens of billions of dollars,
with more than \$1.5 billion in annual losses in the USA alone. There
are innumerable small to medium-size slope failures that cumulatively
impose costs to society as great or greater than the large infrequent
catastrophic landslides that draw so much attention. Landslides can
alter habitat and impact resources down slope and add sediment to
waterways.

### \*Soil and sediment erosion: Soil erosion is an important social and economic problem and an essential factor in assessing ecosystem health and function. Estimates of erosion are essential to issues of land and water management, including sediment transport and storage in lowlands, reservoirs, estuaries, and irrigation and hydropower systems. In the USA, soil has recently been eroded at about 17 times the rate at which it forms. 

### \*Soil quality: As one of Earth\'s most vital ecosystems, soil is essential for the continued existence of life on the planet. As sources, stores, and transformers of plant nutrients, soils have a major influence on terrestrial ecosystems. Soils continuously recycle plant and animal remains, and they are major support systems for human life, determining the agricultural production capacity of the land. Soils buffer and filter pollutants, they store moisture and nutrients, and they are important sources and sinks for CO~2~, methane and nitrous oxides. Soils are a key system for the hydrological cycle \[see groundwater chemistry in the unsaturated zone\]. Soils also provide an archive of past climatic conditions and human influences.

### 

### \*Subsurface temperature regime: The thermal regime of soils and bedrocks exercises an important control on the soil ecosystem, on near-surface chemical reactions (e.g. involving groundwater), and on the ability of these materials to sequester or release greenhouse gases. It may affect the type, productivity and decay of plants, the availability and retention of water, the rate of nutrient cycling, and the activities of soil microfauna. It is also of major importance as an archive of climate change, indicating changes in surface temperature over periods of up to 2-3 centuries, for example in regions without a record of past surface temperatures. In permafrost, the ground temperature controls the mechanical properties of the soils, especially during the freeze-thaw transition in the active layer. 

### \*Sediment sequence and composition: The chemical, physical and biological character of aquatic sediments can provide a finely resolvable record of environmental change, in which natural events may be clearly distinguishable from human inputs. 

### \*Surface displacement: Most surface displacements have but minor effects on landscapes and ecosystems. However, there are exceptions, such as where drainage channels are suddenly displaced by faults, or where seismically-induced uplift raises intertidal ecosystems above sea-level. Moreover, extraction of fluids can induce land subsidence and cause flooding, especially of coastal parklands near sea-level. Subsidence damages buildings, foundations and other built structures. 

#### **What does geologic monitoring look like and who does it?**

**Geologic monitoring involves collecting information through observing,
measuring and sampling elements of geologic processes at work and their
resulting geologic features. This can be done on the ground or remotely
and by an individual or a team. Some monitoring is very complex
requiring sophisticated instruments employed by scientists and trained
technicians; while other types of geologic monitoring utilizes standard
measuring and recording devices that others can operate with little
training required.**

**When parks consider vital indicators, it is important to be familiar
with the monitoring activities they can expect and any potential for
damage to park resources. No one wants to have a swarm of rock
hammer-wielding geologists show up in their park - And, that is not what
it takes to measure geoindicators. Since geoindicators are measures of
processes at or near the surface that change rapidly, they focus less on
the hard rock and more on rates of moving material, and physical and
topographic change. Activities associated with monitoring of
geoindicators include using GPS, aerial photography, seismography,
temperature readings, remote sensing, surveying, measuring flow rates,
gathering meteorology data, and others. Monitoring of geoindicators can
easily be conducted in a resource-sensitive and park friendly maner.**

**Who should do the geologic monitoring? In many instances a team will
do monitoring. In some cases scientists and highly trained technicians
will be needed to do the geologic monitoring but often other park staff
or non-park personnel such as students, retirees, or volunteer
participants can carry out routine measurements or observations.
However, in all instances park personnel should be "active" members of
the monitoring team. Park involvement will insure that the NPS stays
connected to the monitoring project, park needs continue to be
addressed, management is kept informed, and information transfer extends
throughout the NPS network. Because park staff are located on-site they
will probably be most effective in implementing field activities and
recording the data in park databases, such as, GIS and Synthesis.**

Guidance for the design of monitoring programs for geologic resources in
the 32 monitoring networks

This section outlines the recommend steps each monitoring network should
follow to ensure adequate planning for the monitoring of geologic
indicators. Although a few monitoring networks may have already
addressed some of these steps, the guidance outline should help all
networks to ensure a comprehensive review of their geologic monitoring
needs.

A. Identify geologic expertise:

> 1\. Most networks do not have geologic expertise and will need to
> develop a team of specialists to consult with them for evaluation and
> design of geologic monitoring. The Geologic Resources Division is
> available to all networks to help locate geoscientists for this
> purpose - Contact Bob Higgins, Supervisory Geologist, GRD for
> assistance, bob_higgins@nps.gov, or call (303) 969-2018.
>
> 2\. Geologic expertise will be identified from the geologic community
>
> a\) GRD geology staff and other NPS geologists
>
> b\) U.S. Geological Survey
>
> c\) American Association of State Geologists
>
> d\) Geological Society of America
>
> e\) University partners
>
> f\) Museum geologists
>
> 3\. Networks should recruit geoscientists to participate in workshops,
> review proposed monitoring strategies and design monitoring protocols.

B. Have geoscience contact(s) compile a summary of existing geologic
monitoring and information sources for the network.

C. Have geoscientists participate in network workshops to:

> 1\. Rate importance of 27 geoindicators and determine which ones are
> significant for monitoring in parks within the network;
>
> 2\. Compile a description of alternatives (methods) for comprehensive
> monitoring of all priority geoindicators of environmental change,
> including any potential for using existing monitoring done by other
> organizations;
>
> 3\. Work with network resource specialists to identify preferred
> options for implementing geologic monitoring in parks (cost effective,
> resource friendly, easy to measure and replicative for time series
> analysis with adequate accuracy and precision);
>
> 4\. Write a geology panel report for the network (based on network
> format or outline below);
>
> Introduction
>
> Summary of group discussion
>
> Results - for each vital sign chosen, report the following:

-   Management Issue:

-   Monitoring Question Addressed:

-   Vital Sign:

-   What ecosystems does this Vital Sign apply to?

-   Why was this vital sign chosen?

-   Other information (monitoring information, protocols, costs,
    potential partners, related on-going research, suggested inventory
    needs, reviewers, etc.):

-   Contact person:

> Methods
>
> Design and Implementation
>
> 5\. Recommend specialists to design specific monitoring protocols (in
> some instances, panel members can do this at the workshop).

D. Continuing Geologic Monitoring Process

> 1\. Networks will need to incorporate geologic resource monitoring
> into their ecosystem monitoring program under GPRA goal Ib3 and their
> long-term monitoring programs.
>
> 2\. The NPS Geologic Resource Division will continue to be available
> to parks and networks to implement monitoring strategies, facilitate
> partnerships and reevaluate monitoring protocols as the program
> evolves.
>
> 3\. In many cases, the geoscientists that participate in network
> workshops will be willing to assist with developing partnership
> agreements to collect, process and analyze data.
>
> Appendices
>
> A. Desert Biotic Crusts and Pavements
>
> B. Dune Formation and Reactivation
>
> C. Frozen Ground Activity
>
> D. Glacier Fluctuations
>
> E. Karst Processes
>
> F. Relative Sea Level
>
> G. Sediment Sequence and Composition
>
> I. Seismicity
>
> J. Shoreline Position
>
> K. Slope Failure (landslides)
>
> L. Soil and Sediment Erosion
>
> M. Soil Quality
>
> N. Stream Channel Morphology
>
> O. Stream Sediment Storage and Load
>
> P. Subsurface Temperature Regime
>
> Q. Surface Displacement
>
> R. Volcanic Unrest
>
> S. Wind Erosion

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Desert Biotic Crusts and Pavements**          | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** The appearance or disappearance of thin (mm to
cm) surface crusts in playas and depressions in arid and semi-arid
regions may indicate changes in aridity. The formation of persistent
deep, polygonal cracks in the mud and silt floors of closed basins and
depressions may indicate the onset of aridification or severe drought.
Surfaces may contain other desiccation features such as sedimentary
dikes, evaporite deposits (especially gypsum and halite), adhesion
ripples and large salt polygons.

**Significance:** Desert surface crusts are important because they
protect the underlying fine material from wind erosion.

**Environment where Applicable**: Arid to semi-arid terrains

**Types Of Monitoring Sites:** Playas and sabkhas in arid regions

**Method Of Measurement:** Field measurements of feature size, depth and
extent, supplemented by ground surveys, air photos, and satellite
images.

**Frequency of Measurement**: Fissures: 1-50 years. Crusts: 5-10 years

**Limitations of Data and Monitoring**: Surface features may not be
preserved.

**Possible Thresholds:** NA

**Key References**:

Dunbar, R.B. & J.E. Cole 1993. Coral records of ocean-atmosphere
variability. Report from the Workshop on Coral Paleoclimate
Reconstruction, NOAA Climate and Global Change Program, La Parguera,
Puerto Rico, Nov. 5-8, 1992.

Pernetta, J.C. (ed) 1993. Monitoring coral reefs for global change.
Cambridge, International Union for the Conservation of Nature.

Shen, G. 1996. Rapid change in the tropical ocean and the use of corals
as monitoring systems. In Berger, A.R. & W. J. Iams (eds).
Geoindicators: Assessing rapid environmental changes in earth
systems:141-146. Rotterdam: A.A. Balkema.

**Related Environmental And Geological Issues**: Changes in quality of
shallow groundwater.

**Overall Assessment**: Surface crusts and fissures in deserts are good
indicators of rapid changes in precipitation and temperature

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | # GEOLOGIC RESOURCE MONITORING PARAMETERS       | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Dune Formation and Reactivation**             | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Dunes and sand sheets develop under a range of
climatic and environmental controls, including wind speed and direction,
and moisture and sediment availability. In the case of coastal dunes,
sea-level change and beach and nearshore conditions are important
factors. Organized dune systems and sheets in continental environments
form from sediment transported or remobilized by wind action. New
generations of dunes may form from sediment remobilized by climatic
change and/or human disturbances.

Dune formation and movement is well documented from the margins of many
deserts, as well as from temperate regions and along sandy coasts \[see
shoreline position\]. Sand movement is inhibited by moisture and
vegetation cover, so that dunes can also be used as an indicator of
near-surface moisture conditions. Changes in dune morphology or position
may indicate variations in aridity, wind velocity and direction \[see
wind erosion\], or disturbance by humans. Dune changes can be correlated
with climatic variables using aridity indices and the dune mobility
index, which is the ratio between available wind energy and the
precipitation-potential evapotranspiration ratio.

**Significance:** Moving dunes may engulf houses, fields, settlements
and transportation corridors. Active dunes in sub-humid to semi-arid
regions decrease arable land for grazing and agriculture. They also
provide a good index of changes in aridity. Coastal dunes are important
determinants of coastal stability, supplying, storing and receiving sand
blown from adjacent beaches. Dunes play an important role in many
ecosystems (boreal, semi-arid, desert, coastal) by providing
morphological and hydrological controls on biological gradients.

**Environment where Applicable:** Sand dunes occur widely - in deserts,
in tropical and sub-tropical latitudes, semi-arid continental
mid-latitude regions. They also occur along sandy ocean beaches,
estuaries and lake shorelines from the Arctic to the Equator.

**Types of Monitoring Sites:** Margins of active dune areas. Sand hills
and vegetation-stabilized dunes in mid-continental areas, ideally
located along climatic transects.

**Method of Measurement:** Changes in size, shape and position of sand
sheets and dune fields can be monitored by repeated ground surveys and
measurement of active and dormant/relict dunes, by air photos, or by
satellite images.

**Frequency of Measurement:** Dune systems should be monitored every
5-10 years to observe changes associated with drought cycles, more
frequently when movement is detected.

**Limitations of Data And Monitoring:** Climatic records, especially
wind data, are commonly lacking.

**Possible Thresholds:** Dune mobility index M\>50, where M is the ratio
between (1) the percentage of the time the wind blows above about 5
m/sec (the threshold velocity for sand transport), and (2) annual
rainfall divided by potential transpiration. Other thresholds could be
based on acceptable limits for active dune areas on agricultural land,
as well as on associated groundwater levels.

**Key References:**

Berger, A.R. & W.J.Iams (eds). Geoindicators: Assessing rapid
environmental changes in earth systems. Rotterdam: A.A. Balkema. (Papers
by Vance & Wolfe and Lancaster).

Cooke, R., A.Warren & A.Goudie 1993. Desert geomorphology. London, UCL
Press.

McKee, E.D. 1979. A study of global sand seas. U.S. Geological Survey
Professional Paper 1052.

Muhs, D.R. & V.T.Holliday 1995. Active dune sand on the Great Plains in
the 19th Century: evidence from accounts of early explorers. Quaternary
Research 43: 118-124.

Nordstrom, K.F., N.Psuty & B.Carter 1990. Coastal dunes: form and
process. Chichester, John Wiley and Sons.

**Related Environmental and Geological Issues**: Mobile dunes may invade
and destroy productive agricultural land and affect transportation
routes. Human efforts to stabilize dunes commonly fail because they
introduce disequilibrium structures that run counter to natural trends.
Many efforts have been made to stabilize dunes, especially in coastal
complexes by planting sand-binding vegetation. Dune migration may affect
shallow water table levels by reducing surface evaporation.

**Overall Assessment:** Dunes are very important indicators of
environmental change in arid and semi-arid regions and coastal zones.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | # GEOLOGIC RESOURCE MONITORING PARAMETERS       | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Frozen Ground Activity**                      | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Permafrost is present in 13% (18 million km2) of
the world\'s soils . In permafrost and other cryogenic (periglacial)
areas and in temperate regions where there is extensive seasonal
freezing and thawing of soils, a wide range of processes lead to a
variety of surface expressions, many of which have profound effects on
human structures and settlements, as well as on ecosystems. These
sensitive periglacial features are found around glaciers, in high
mountains (even at low-latitudes) and throughout polar regions. The
development (aggradation) or degradation of permafrost is a sensitive
and early indicator of climate change \[see subsurface temperature
regime\]. Important geological parameters related to permafrost regions
include:

1\. Active layer thickness: The thickness of the active layer, the zone
of annual freezing and thawing above permafrost, determines not only the
overall strength of the ground but also many of the physical and
biological processes that take place in periglacial terrains. Soil
moisture and temperature, lithology and landscape morphology exercise
important controls on active layer thickness. Soil moisture and
temperature depend largely on climatic factors, so that if the mean
annual air temperature rises several degrees Celsius, the thickness of
the active layer may change over time periods of years to decades.

2\. Frost heaving is a basic physical process associated both with near
surface winter freezing and with deeper permafrost aggradation. Frost
heaving can displace buildings, roads, pipelines, drainage systems and
other structures. Many frozen soils have a much greater water content
than their dry equivalents and undergo a local 10-20% expansion in soil
volume during freezing. The frost heave process and the consequences of
thawing are of great importance in the development of many of the unique
features of cold terrains, including perennial hummocks and seasonal
mounds, patterned ground, palsas and pingos.

3\. Frost cracks are steep fractures formed by thermal contraction in
rock or frozen ground with substantial ice content. They commonly
intersect to create polygonal patterns, which may lead to the formation
of wedges of ice and surficial material. The frequency of cracking is
linked to the intensity of winter cold. Where climate is warming,
ice-wedge casts replace ice wedges over periods of decades.

4\. Icings are sheetlike masses of layered ice formed on the ground
surface, or on river or lake ice, by freezing successive flows of water
that may seep from the ground, flow from a spring or emerge from below
river or lake ice through fractures. The intensity of icings in the
southern portions of the permafrost zone may change annually, increasing
with colder winters and lower snow cover combined with autumnal
precipitation. Further north, icings increase in size but decrease in
number when the climate cools, and vice-versa when it warms.

5\. Thermoerosion refers to erosion by water combined with its thermal
effect on frozen ground. Small channels can develop into gullies up to
several kms in length, growing at rates of 10-20 m/year, and in sandy
deposits, as fast as 1 m/hour. The main climatic factors controlling the
intensity of thermoerosion are snow melt regime and summer
precipitation.

6\. Thermokarst refers to a range of features formed in areas of low
relief when permafrost with excess ice thaws. These are unevenly
distributed and include hummocks and mounds, water-filled depressions,
'drunken' forests, mud flows on sloping ground, new fens, and other
forms of thaw settlement that account for many of the geotechnical and
engineering problems encountered in periglacial landscapes. Even where
repeated ground freezing takes place, thermokarst features, once formed,
are likely to persist.

7\. Permafrost terrains are characterized by a wide range of slow
downslope movements involving creep, such as rock glaciers and
gelifluction, and by more rapid landslides and snow avalanches \[see
slope failure\].

**Significance:** Permafrost influences natural and managed ecosystems,
including forests, grasslands and rangelands, mountains and wetlands,
and their hydrological systems. It is an agent of environmental change
that affects ecosystems and human settlements. Permafrost may enhance
further climate change by the release of carbon and other greenhouse
gases during thawing. It is estimated that nearly 1/4 of the world\'s
terrestrial carbon is tied up in dead organic mater in the active layer
and in permafrost: long-term climate warming would facilitate
decomposition and drying, releasing huge quantities of methane and CO2
\[see wetlands extent, structure and hydrology\]. Permafrost can result
in serious and costly disruptions from ground subsidence, slope failure,
icings, and other cryogenic processes.

**Environment where Applicable:** High and medium latitudes and high
altitudes (arctic and cold deserts, tundra, taiga, mountains) where
ground freezing is extensive.

**Types of Monitoring Sites**: Vegetated polar regions, high altitude
locations, areas of obvious disturbance of the active layer (e.g.
icings, polygons, failing slopes, areas of frost heaving).

**Method of Measurement:** There are many approaches to the monitoring
of permafrost activity:

1\. Active layer thickness can be easily measured, except in coarse and
bouldery soils, by probing with a steel rod. Geophysical techniques such
as ground probing radar can be useful for detecting relatively large
changes in thaw depth. More accurate measurements may be obtained using
relatively inexpensive frost tubes, which can be utilized over any time
interval, though, ideally, active layer data should be collected at
regular intervals from time of snowmelt until annual freezeup. Soil
temperature probes are also useful \[see subsurface temperature
regime\].

2\. Frost heaving can be determined by scribers mounted on the outside
of frost tubes, or by other scriber recorders, which permit maximum
annual heave to be measured. Heaving associated with deeper freezing
(permafrost aggradation) can be assessed through repeated levelling of
an area. In the case of drained basins where aggradation can be quite
rapid annual determinations are best, but, in general, surveys over
periods of decades will suffice.

3\. Frost crack patterns on ice wedges can be measured annually by the
use of breaking cables that record crack opening and spreading.

4\. The persistence of icings through a summer is an indication of the
relative warmth of the season. In colder years icings persist. Where
springs are common, change over years to decades can be deduced from
sequential air photos or satellite images.

5\. The frequency and distribution of thermoerosion and thermokarst
provide indicators of regional change, readily assessed over periods of
years to several decades with sequential air photos of satellite images.

6\. Slope stability and creep can be measured by installed inclinometer
tubes, though these may become inoperable after considerable creep has
taken place.

**Frequency of Measurement:** Depends on the kind of disturbance being
monitored, as detailed above. Certain features need to be checked weekly
to several times during a summer season, others on an annual or decadal
basis.

**Limitations of Data and Monitoring:** It is difficult to do field work
in areas of active thawing without disturbing mobile soils and landforms
or without endangering sensitive ecosystems. In response to highly
variable local conditions, grids installed to monitor polygon
development should be left in place or extended from year to year.

**Possible Thresholds:** The freeze-thaw transition is a major threshold
that, once crossed, may lead to the development of various landforms,
some of which (e.g. thermokarst) are irreversible at least on time
scales of less than centuries. Many frozen ground features are closely
linked to the ground thermal regime, and changes in moisture conditions
or in vegetation or snow cover can offset changes in air temperature
\[see subsurface temperature regime\].

**Key References:**

Romanovskii, N., G.F.Gravis, M.O.Leibman & E.Melnikov 1996. Periglacial
processes as geoindicators in the cryolithozone. In Berger, A.R. &
W.J.Iams (eds). Geoindicators: Assessing rapid environmental changes in
earth systems:33-54. Rotterdam: A.A. Balkema. (see also paper by Rasch
et al.)

Washburn, A.L. 1980. Geocryology. New York, Wiley & Sons, Halstead
Press.

Williams, P.J. & M.W.Smith 1989. The frozen Earth - fundamentals of
geocryology. Cambridge: Cambridge University Press.

**Related Environmental and Geological Issues:** Thawing effects are
hazardous to animal and human habitation, and permafrost ecosystems are
easily disturbed.

**Overall Assessment:** Frozen ground (permafrost and periglacial)
activity is sensitive to local climate, hydrology, and vegetation cover.
Apart from the thickness of the active layer, which is a most useful
indicator of local environmental change, most frozen ground features
reflect regional change about the freezing point and require much effort
to monitor.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Glacier Fluctuations**                        | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Changes in glacier movement, length and volume
can exert profound effects on the surrounding environment, for example
through sudden melting which can generate catastrophic floods, or surges
that trigger rapid advances (in the recent surge of the Bering Glacier,
Alaska, as much as 12 km in a 60 day period). Standard parameters
include mass balance and the glacier length, which determines the
position of the terminus. The location of the terminus and lateral
margins of ice and rock glaciers exerts a powerful influence on nearby
physical and biological processes. Through a combination of specific
balance, cumulative specific balance, accumulation area ratio and
equilibrium-line altitude, mass balance reflects the annual difference
between net gains (accumulation) and losses (ablation). It may also be
important to track changes in the discharge of water from the glacier as
indicators of glacier hydrology. Abrupt changes may warn of impending
acceleration in melting, cavitation, or destructive flooding.

**Significance:** Glaciers are highly sensitive, natural, large-scale,
representative indicators of the energy balance at the Earth\'s surface
in polar regions and high-altitudes. Their capacity to store water for
extended periods exerts significant control on the surface water cycle.
The advance and retreat of mountain glaciers creates hazards to nearby
human structures and communities through avalanches, slope failure,
catastrophic outburst floods from ice and moraine-dammed lakes.
Notwithstanding local glacier advances, the length of mountain glaciers
and their ice volume has decreased throughout the world during the past
century or two, providing strong evidence for climate warming, though
there may also be local correlations with decreasing precipitation. It
is estimated that the European Alps have lost more than half their ice
in the past century

**Environment where Applicable:** Wherever glaciers and icecaps occur.

**Types Of Monitoring Sites:** Selected glacier forelands and icecaps
strategically located to record climate changes, or liable to rapid
advances/retreats that may affect fluvial systems or nearby settlements.

**Method of Measurement:** Analysis of air photos and high-resolution
satellite images, ground surveys. GPS data may be useful in detecting
glacial surges and estimating the volume of ice being transferred

**Frequency of Measurement:** Annually, more frequently where glaciers
are surging.

**Limitations of Data and Monitoring:** The monitoring of continental
glaciers, such as the Antarctic and Greenland ice sheets, is a complex
matter, and there is no easy technique for detecting volume changes that
will affect sea levels. Horizontal advances or retreats of an ice sheet
margin may not provide timely information on volume changes, and field
studies of mass balance can never adequately cover the entire ice sheet.

**Key References:**

Hambrey, M. 1994. Glacial environments. London, UCL Press.

Matthews, J.A., 1992. The ecology of recently-deglaciated terrain: a
geoecological approach to glacier forelands and primary succession.
Cambridge University Press.

Nesje, A. 1996. Geological indicators of rapid environmental change -
glacier fluctuations and avalanche activity. In Berger, A.R. & W.J.Iams
(eds). Geoindicators: Assessing rapid environmental changes in earth
systems:17-32. Rotterdam: A.A. Balkema.

UNEP/GEMS, 1992. Glaciers and the environment. United Nations
Environment Programme, Environment Library 9.

**Related Environmental and Geological Issues:** Glacier melting can
sometimes trigger catastrophic flood outbursts (jökulhlaups) from
marginal lakes blocked by moraines, though failure of these natural dams
may have a variety of other causes. The decreasing capacity of
retreating glaciers to store water affects downstream water supply and
thus the availability of water for agriculture and human consumption.
Glacier forelands newly exposed in front of receding glaciers provide
excellent natural laboratories to study plant succession and soil
development.

**Overall Assessment:** Fluctuations in glaciers are among the most
sensitive indicators of climatic change. They can be also used as
indicators of temperature and precipitation changes that occurred prior
to instrumental weather records.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Karst Processes**                             | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Karst is a type of landscape found on carbonate
rocks (limestone, dolomite, marble) or evaporites (gypsum, anhydrite,
rock salt) and is typified by a wide range of closed surface
depressions, a well-developed underground drainage system, and a paucity
of surface streams. The highly varied interactions among chemical,
physical and biological processes have a broad range of geological
effects including dissolution, precipitation, sedimentation and ground
subsidence. Diagnostic features such as sinkholes (dolines), sinking
streams, caves and large springs are the result of the solutional action
of circulating groundwater, which may exit to entrenched effluent
streams. Most of this underground water moves by laminar flow within
narrow fissures, which may become enlarged above, at or below the water
table to form subsurface caves, in which the flow may become turbulent.
Caves contain a variety of dissolution features, sediments and
speleothems (deposits with various forms and mineralogy, chiefly
calcite), all of which may preserve a record of the geological and
climatic history of the area. Karst deposits and landforms may persist
for extraordinarily long times in relict caves and paleokarst.

Karst can be either a sink or a source of CO2, for the karst process is
part of the global carbon cycle in which carbon is exchanged between the
atmosphere, surface and underground water and carbonate minerals.
Dissolution of carbonates, which is enhanced by the presence of acids in
water, ties up carbon derived from the rock and from dissolved CO2 as
aqueous HCO3-. Deposition of dissolved carbonate minerals is
accompanied - and usually triggered - by release of some of the carbon
as CO2. In many karst locations, CO2 emission is associated with the
deposition of calcareous sinter (tufa, travertine) at the outlet of cold
or warm springs.

Though most abundant in humid regions, karst can also be found in arid
terrains where H2S in groundwater rising from reducing zones at depth
oxidizes to produce sulphuric acid, which can form large caves, such as
the Carlsbad Caverns of New Mexico. Similar processes also operate in
humid regions but tend to be masked by the CO2 reaction. Sulphates and
rock salt are rarely exposed in humid climates. They are susceptible to
rapid dissolution during periodic rains where they are at the surface in
drier terrains.

**Significance:** It is estimated that karst landscapes occupy up to 10%
of the Earth\'s land surface, and that as much as a quarter of the
world\'s population is supplied by karst water. The karst system is
sensitive to many environmental factors. The presence and growth of
caves may cause short-term problems, including bedrock collapse,
disparities in well yields, poor groundwater quality because of lack of
filtering action, instability of overlying soils, and difficulty in
designing effective monitoring systems around waste facilities.
Instability of karst surfaces leads annually to millions of dollars of
damage to roads, buildings and other structures in North America alone.
Radon levels in karst groundwater tend to be high in some regions, and
underground solution conduits can distribute radon unevenly throughout a
particular area.

Because the great variety of subsurface voids and deposits are protected
from surface weathering and disturbance, karst preserves a record of
environmental change more faithfully than most other geological
settings. Temperature, rainfall, nature of soil and vegetation cover,
glaciation, fluvial erosion and deposition, and patterns of groundwater
flow can usually be read from cave patterns and deposits. This record
can be resolved on an annual scale in the case of certain fast-growing
speleothems \[see coral chemistry and growth patterns\].

**Environment where Applicable**: Karst is most common in carbonate
terrains in humid regions of all kinds (temperate, tropical, alpine,
polar), but processes of deep-seated underground dissolution can also
occur in arid regions.

**Types of Monitoring Sites:** Caves provide unique, productive and
extensive field sites, because they allow direct observation and mapping
of underground features and their relation to the surface and to
groundwater flow. Furthermore, their origin, morphology and distribution
patterns are the dominant factors in controlling the nature of the
overlying land surface (e.g. distribution of sinkholes) and the
directions of groundwater movement. Wells, borings and quarries are less
useful as monitoring sites, because they provide only discontinuous
points of information.

**Method of Measurement:** A holistic approach is required for karst
studies, one that addresses the entire suite of interacting features and
processes: geology, chemistry, engineering, soil science, biology,
meteorology and, especially, hydrology must all be involved.
Hydrological and geochemical measurements of springs, sinking streams,
drip waters into caves, and cave streams provide records of short-term
changes in water quality and chemical processes. The most important
variables include pH, temperature, Ca, Mg, Na, Cl, HCO3, and SO4.
Pumping tests on wells are useful in clarifying the nature of the
porosity and permeability of karst aquifers, as are simple monitoring of
natural changes in water levels in cave streams. Dye tracing is a useful
technique for demonstrating patterns of underground flow and delineating
drainage divides, which may vary with time. Studies of the mineralogy
and geochemistry of cave precipitates (using X-ray diffraction,
luminescence, isotope ratios and trace elements) can reveal past changes
in temperature, humidity, infiltration rates and groundwater chemistry.
In built-up areas it is important to locate buried cavities and to
monitor their potential for collapse, using a combination of geophysical
surveys, exploratory drilling and repeated levelling.

**Frequency of Measurement:** Surface features and soils in karst
terrains are notoriously unstable and can change rapidly, commonly at
catastrophic rates. In humid climates, most surface collapses occur
during or soon after floods, when soil and debris is eroded from beneath
incipient sinkholes. Groundwater chemistry and contamination change so
rapidly during floods that continuous measurements are needed in order
to interpret the karst system.

**Limitations of Data and Monitoring:** Surface studies of karst are
hampered by the fact that surface features are controlled by underground
water movement, without knowledge of which it is impossible to interpret
the surface features properly. Changes in karst are often so sudden that
it is difficult to design a valid monitoring strategy.

**Possible Thresholds:** The slow, gradual movement of soil tends to
fill depressions in the karst bedrock surface, keeping pace with the
solutional growth of sinkholes. However, where this material can be
transported away from the site by cave streams, an arch of rock and soil
can be produced over an underground void, resulting in sudden collapse.
The threshold between gradual and catastrophic subsidence is not
generally predictable from the surface. There is, however, an important
threshold between dissolution and precipitation, which is governed by
the degree of saturation of karst water with respect to minerals,
especially calcite. The threshold can be crossed for a number of
different reasons, with CO2 level enhanced by decay processes and
reduced by aeration. Calcite and CO2 solubility both decrease with
temperature, but high temperatures generate greater CO2 production,
which in turn offsets the diminution of CO2 solubility. Solution
conduits form along paths of greatest groundwater discharge, with their
rate of enlargement at first determined by discharge rates and
saturation concentration. Once the water is able to pass through the
conduit without exceeding the threshold for calcite solubility (about
70% saturation), the enlargement rate becomes almost independent of
discharge and is determined by dissolution kinetics.

**Key References:**

Beck, B.F. 1989. Engineering and environmental implications of sinkholes
and karst. Rotterdam: Balkema.

Ford, D.C. & P.W.Williams 1989. Karst geomorphology and hydrology.
London: Unwin Hyman.

Jennings, J.N. 1985. Karst geomorphology Oxford: Basil Blackwell.

White, W.B. 1988. Geomorphology and hydrology of karst terrains. Oxford:
Oxford University Press.

**Related Environmental and Geological Issues:** Flooding of caves in
highly populated areas can disperse contaminants over wide areas. For
example, in the mid-1980s, flood-induced ponding of water under high
pressure in caves beneath the city of Bowling Green, Kentucky dispersed
hydrocarbons (from industrial wastes) throughout many fissures, bringing
their concentration to nearly explosive levels in overlying basements
and nearby wells. Under steep hydraulic gradients, fissures may enlarge
sufficiently to cause significant leakage through the ground during a
human lifetime, as around some of the Tennessee Valley Authority dams in
the mid-twentieth century. The most vexing problem in karst today is the
lack of rational regulations concerning groundwater monitoring, a
situation complicated by a common misunderstanding of the great
differences in flow behaviour between karst and non-karst (porous-media)
aquifers.

**Overall Assessment:** Karst landscapes are particularly dynamic and
subject to rapid change. They preserve a valuable record of
environmental change, and should be monitored closely for their effect
on human settlements and built structures.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | # GEOLOGIC RESOURCE MONITORING PARAMETERS       | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Relative Sea Level**                          | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** The position and height of sea relative to the
land (relative sea level - RSL) determines the location of the shoreline
\[see shoreline position\]. Though global fluctuations in sea level may
result from the growth and melting of continental glaciers, and
large-scale changes in the configuration of continental margins and
ocean floors, there are many regional processes that result in rise or
fall of RSL that affect one coastline and not another. These include:
thermal expansion of ocean waters, changes in meltwater load, crustal
rebound from glaciation, uplift or subsidence in coastal areas related
to various tectonic processes (e.g. seismic disturbance and volcanic
action), fluid withdrawal, and sediment deposition and compaction. RSL
variations may also result from geodetic changes such as fluctuations in
the angular velocity of the Earth or polar drift. Tide-gauge records
suggest an average global sea-level rise over the past century of 0 to 3
mm per year, though there is no firm evidence of acceleration in these
rates. Indeed, a recent study by the US Environmental Protection Agency
predicts that global sea level is likely to rise 15 cm by 2050 (about 3
mm/year) as a result of human-induced climate warming.

**Significance:** Changes in RSL may alter the position and morphology
of coastlines, causing coastal flooding, waterlogging of soils and a
loss or gain of land. They may also create or destroy coastal wetlands
and salt marshes, inundate coastal settlements, and induce salt-water
intrusion into aquifers, leading to salinization of groundwater. Coastal
ecosystems are bound to be affected, for example, by increased salt
stress on plants. A changing RSL may also have profound effects on
coastal structures and communities. Low-lying coastal and island states
are particularly susceptible to sea level rise. It is estimated that 70%
of the world\'s sandy beaches are affected by coastal erosion induced by
RSL rise.

**Environment where Applicable**: Marine coastlines

**Types of Monitoring Sites:** Near harbors, shore installations and
coastal communities. Holocene RSL trends can be investigated through
geological studies of beach ridge plains, coastal terraces, coral reefs
and other 'bioconstructions', beaches, marshes, the intertidal zone, and
coastal archaeological sites.

**Method of Measurement:** Tide gauges, GPS techniques, and re-leveling
surveys to identify changes in coastal land elevation. Holocene RSLs are
commonly documented by locating a feature associated with a former sea
level and determining its present elevation and age. In general, coastal
lagoons, barrier coral reefs, and flooded river mouths imply
submergence. More specific indicators include raised strandlines and
marine shell deposits, drowned coastal deposits, and saltwater to
freshwater transitions in silled basins.

**Frequency of Measurement:** Continuous for tide gauges, less frequent
for other techniques such as re-levelling.

**Limitations of Data and Monitoring:** Though there are many ways to
tell whether RSL has changed in a particular area, distinguishing land
subsidence or uplift from submergence or recession due to other sources
of sea-level change is difficult. For modern RSL, a datum is required,
and because of high frequency variability, more than 30 years of data
may be needed to establish a reliable trend. For Holocene RSLs, the lack
of true sea-level indicators and the coarse temporal resolution make
interpretation difficult. There are also errors introduced when dating
geological and geomorphological features and when using them to
determine the exact RSL position. Note that most of the RSL work has
been carried out in the Northern Hemisphere (especially on both sides of
the North Atlantic) and in the more developed countries: few RSL curves
apply to Africa, Latin America, or Oceania or southern Asia.

Possible Thresholds: An important threshold is crossed when sea levels
rise above the mean land elevation of coastal communities and
terrestrial ecosystems or, at least, above a high-water level to which
they have become adapted.

**Key References**:

Berger, A.R. & W.J.Iams (eds). Geoindicators: Assessing rapid
environmental changes in earth systems. Rotterdam: A.A. Balkema. (see
papers by Forbes & Liverman and Morton).

Emery, K.O. & D.G.Aubrey 1991. Sea-levels, land levels and tide gauges.
New York:

Springer-Verlag.

French, J.R., T.Spencer & D.J.Reed (eds) 1995. Geomorphic response to
sea level rise: existing evidence and future impacts. Special issue of
Earth Surface Processes and Landforms 20/1: 1-103.

Pirazzoli, P.A. 1991. World atlas of Holocene sea-level changes.
Amsterdam: Elsevier.

Titus, J.G. & V.K.Narayanan 1995. The probability of sea level rise. US
Environmental Protection Agency, Office of Policy, Planning and
Evaluation.

Van de Plaasche, O. (ed) 1986. Sea level changes: a manual for the
collection and evaluation of data. Norwich, UK: Geo-Books.

Warwick, R.A., E.M.Barrow & T.M.L.Wigley 1993. Climate and sea level
change: observations, projections and implications. Cambridge: Cambridge
University Press.

**Related Environmental and Geological Issues:** Many geomorphological
changes in the marine coastal zone are affected by fluctuations in RSL.
Low-lying islands and coastal cities are vulnerable to rising sea
levels.

**Overall Assessment:** Understanding changes in coastal environments
requires monitoring of relative sea levels.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary

of a wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Sediment Sequence and Composition**           | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Lakes, wetlands, streams (and overbanks),
estuaries, reservoirs, fjords, shallow coastal seas and other bodies of
marine or fresh water commonly accumulate deposits derived from
bedrocks, soils, and organic remains within the drainage basin, though
fine particles can also be blown in by winds from distant natural, urban
and industrial sources. These aquatic deposits may preserve a record of
past or on-going environmental processes and components, both natural
and human-induced, including soil erosion \[see soil and sediment
erosion; wetlands extent, structure and hydrology\], air-transported
particulates \[see dust storm magnitude, duration and frequency\],
solute transport, and landsliding \[see slope failure\].

Some of these bodies of water are dynamic and sensitive systems whose
sedimentary deposits preserve in their chemical, physical and biological
composition a chronologically ordered and resolvable record of physical
and chemical changes through their mineralogy, structure, and
geochemistry (e.g. organic C, biogenic silica, stable O isotopes in
carbonates and cellulose, trace metals) \[see surface water quality\].
Of particular value in determining long-term data on water chemistry are
the remains of aquatic organisms (e.g. diatoms, chrysophytes,
chironomids, and other algae and invertebrates) which can be correlated
with various environmental parameters. In addition, fossil pollen,
spores, and seeds reflect past terrestrial and aquatic vegetation.
Sediment deposits can, thus, provide an indication of the degree and
nature of impact of past events on the system, and a baseline for
comparison with contemporary environmental change.

Some lakes (and reservoirs) are open systems characterized by relatively
stable shorelines and a limited residence time for solutes; others are
closed (endorheic) and/or ephemeral (playas). Lake water solute
concentrations may range over five orders of magnitude from dilute,
monsoonal rainwater to viscous chloride brines of 500,000 mg/kg; the pH
may range from less than 2 in some sulphuric-acid rich Japanese crater
lakes to more than 11 in alkaline brines of the East African rift.

**Significance:** The chemical, physical and biological character of
aquatic sediments can provide a finely resolvable record of
environmental change, in which natural events may be clearly
distinguishable from human inputs.

**Environment where Applicable:** Any depositional environment (e.g.
lakes, ponds, estuaries, river bottomlands, lagoons, bays, fjords) where
water permits the accumulation of sediment. River deposits can preserve
useful records, but the precise source and environmental context of
fluvial sediments are commonly uncertain, except for those in oxbow
lakes and meander cut-offs \[see stream sediment storage and load\].

**Types of Monitoring Sites:** Topographic lows which are open water or
wet over the long term. Especially valuable are deposits in lake basins
with no outlets, confined basins with low inflows, and rain-fed
peatlands.

**Method of Measurement**: Surface sediments collected by gravity
corers, grab sampling or dredging are useful for measuring the status of
prime indicators, and may represent the last decade or so, depending on
the local accumulation rate. Surficial deposits are commonly very loose
and hard to collect: special sampling devices may be required, such as
tubes filled with dry ice on which a thin skin of sediment is frozen and
kept stratigraphically coherent. Sediment cores obtained by piston
coring, or drilling from barges or from winter ice are used to determine
the long-term environmental background. A chronology can be established
by measuring unstable isotopes (e.g. 210Pb, 137Cs), datable tephra
layers, or fossil content. There are standard methods of geochemical and
limnological analysis that characterize individual layers which can, in
turn, be dated through a variety of methods. Shipborn acoustic and
seismic investigations can be helpful in establishing stratigraphic
sequences.

Important parameters include humification, mineral content, magnetic
susceptibility, major element, trace element and stable isotope
geochemistry, specific pollutants (e.g. DDT), biogenic silica, fossil
remains, and biochemical markers such as photosynthetic pigments from
blue-green algae. Many of these indicators can be related to
environmental variables using quantitative transfer functions. For
example, biotic fractions, such as diatoms, can provide direct or proxy
data on pH, total lake phosphorous, temperature and salinity. Spores and
pollen grains can reveal past vegetation patterns. Diagnostic indicators
of human activity found in sediments include: pollen or seeds of
cultivated plants; fly-ash, charcoal, soot and oil particles from coal
or oil-fired power stations and industrial and domestic sources; high
concentrations of heavy metals (such as Pb from leaded fuels and
paints), artificial radionuclides, and derivatives from fertilizers and
pesticides; and geochemical gradients related to acidification.

**Frequency of Measurement:** At least every five years. In the case of
modern sediments, which are expected to reflect environmental changes
within a drainage basin or sediment catchment, sampling may be carried
out at monthly, yearly or longer intervals, depending on the rate of
deposition.

**Limitations of Data and Monitoring:** The degree of resolution of past
records depends on deposition rates and sediment preservation, and on
the ability to establish a detailed chronology. This can be difficult,
for temporal and spatial resolution of the record are controlled by
properties of the accumulating system. In some lakes, sediments are
continuously deposited, whereas others, such as playas, dry out
periodically and are less useful as a source of paleo-data. Fluvial
sediments, particularly in estuaries, may preserve a record of
environmental changes, but river systems tend to be more open than
lacustrine. There are also problems with processes that affect organisms
after death (taphonomy) and sediments after their initial deposition,
such as bioturbation and diagenesis. The ecological optima and
tolerances of some indicators are poorly understood. For example, trace
element profiles may reflect human inputs or a natural redistribution in
response to redox potential within the water column.

**Possible Thresholds:** A critical load or threshold may be crossed
when the concentration of pollutants changes the structure or function
of aquatic ecosystems.

**Key References:**

Berglund, B.E. 1986. Handbook of Holocene palaeoecology and
palaeohydrology. New York: John Wiley.

Charles, D.F. & J.P.Smol 1994. Long-term chemical changes in lakes:
quantitative inferences from biotic remains in the sediment record. In
Baker, L (ed) Environmental chemistry of lakes and reservoirs: 3-31.
Advances in Chemistry Series 237, Washington DC: American Chemical
Society.

Hammer, U.T. 1986. Saline lake ecosystems of the world. Dordrecht: W.
Junk Publishers.

Rosen, M.R. (ed) 1994. Paleoclimate and basin evolution of playa
systems. Geological Society of America Special Paper 289.

Smol, J.P. 1995. Paleolimnological approaches to the evaluation and
monitoring of ecosystem health: providing a history for environmental
damage and recovery. In Rapport, D.J., C.L.Gaudet & P.Calow Evaluating
and monitoring the health of large-scale ecosystems: 301-318. Berlin:
Springer-Verlag.

Street-Perrott, F.A. 1994. Palaeo-perspectives: changes in terrestrial
ecosystems. Ambio 23:37-43.

Warner, B.J. (ed) 1990. Methods in Quaternary Ecology St. John\'s, NF:
Geological Association of Canada.

**Related Environmental and Geological Issues:** Paleoenvironmental data
from sediment deposits can provide a record of the impact of distant
human activity (e.g. burning of fossil fuels or the release of
chemicals) on the wider ecosystem. They can be invaluable in
environmental management by providing a baseline for management
decisions within a watershed.

**Overall Assessment:** The chemical, physical and biological
composition of sediment sequences provides one of the best natural
archives of recent environmental changes in terrestrial and aquatic
systems.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Seismicity**                                  | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**BRIEF DESCRIPTION:** Shallow-focus earthquakes (those with sources
within a few tens of kms of the Earth\'s surface) are caused by crustal
movements along strike-slip, normal and thrust faults, though they can
also be induced anthropogenically. They can result in marked temporary
or permanent changes in the landscape, depending on the magnitude of the
earthquake, the location of its epicenter, and local soil and rock
conditions \[see surface displacement\]. Deep-focus earthquakes (below
about 70 km), unless of the highest magnitude, are unlikely to have
serious surface manifestations.

To avoid, reduce or warn of environmental impacts, it is necessary to
know the size, location, and frequency of seismic events. These
parameters can identify active faults and the sense of motion along
them. Also of great importance is the spatial pattern of seismicity,
including the presence of seismic gaps, and the relationship to known
faults and active volcanoes. At least three, and generally many more,
monitoring sites are required to determine the necessary parameters.

Seismic observations constitute one of the oldest forms of systematic
earth monitoring (geoindicators). There are now in operation many
national, regional and international seismic networks, which provide
information about the location, size and motion of earthquakes anywhere
in the world. However, shallow-focus tremors of lower magnitude, may not
be detected by these means, and must be monitored more closely, on a
local basis. Seismic hazard maps can be constructed to identify areas at
varying risk from earthquake damage.

**Significance**: Earthquakes constitute one of the greatest natural
hazards to human society. Between 1960 and 1990 earthquakes killed about
439,000 people worldwide and caused an overall economic loss of some
\$US 65 billion. The 1994 Northridge earthquake in California alone
resulted in over US\$30 billion in property damage, and the 1995 Kobe
earthquake over \$100 billion. Surface effects include uplift or
subsidence, surface faulting, landslides and debris flows, liquefaction,
ground shaking, and tsunamis ('tidal' waves caused by undersea tremors).
Damage to buildings, roads, sewers, gas and water lines, power and
telephone systems, and other built structures commonly occurs.

**Environment where Applicable**: Any area of active tectonics or
weakness in old cratons, or where human activities change subsurface
rock pressures.

**Types of Monitoring Sites:** Remote, away from obvious sources of
ground shaking, such as traffic, mines, quarries, and heavy industry.
For heavily populated areas in seismically-active areas, a dense array
of seismographs is recommended.

**Method of Measurement:** Standard seismographs. These should be able
to record three components of ground acceleration with a dynamic range
of 10-5 to 1 g (acceleration due to gravity) in the frequency band 0.1
to 20.0 Hz, maintaining absolute time to a precision of 5 ms. Monitoring
seismicity induced by mining or fluid extraction activities generally
requires networks of closely-spaced (\<5 km) instruments that can record
considerably higher frequencies (20-1500 Hz) than for natural
seismicity. Seismic data should be transmitted quickly (preferably in
real time) to central analysis units. The effects of increases in
crustal stress, which can be released through earthquakes, is becoming
increasingly important as a tool for estimating seismic hazard. Stress
increase may be detected indirectly in many ways, for example by
monitoring actual earth stress in mines and boreholes, magnetic, gravity
and electric fields, water levels in wells, surface deformation (creep,
tilt, extension or shortening). However, these are not a substitute for
direct observations of seismicity using seismographs.

**Frequency of Measurement**: continuous

**Limitations of Data and Monitoring:** Monitoring seismicity will
identify where earthquakes are likely to occur and their potential
magnitude, but not when they might be expected.

**Possible Thresholds**: A threshold is reached when natural or induced
stresses overcome the strength (resistance to failure) of a rock mass
and rupture occurs, expressed as an earthquake. Several scales of
earthquake magnitude are in common use, based on their surface effects.
Near-surface tremors with magnitudes \<5 may be felt, but are rarely
damaging. Those \>M5 can induce significant damage. Earthquakes above M7
can be expected to have severe environmental and human impacts.

**Key References:**

Bolt, B.A. 1993. Earthquakes, New York: W.H. Freeman.

McGuire, R.K. (ed.) 1993. The practice of earthquake hazard assessment.
International Association of Seismology and Physics of the Earth\'s
Interior.

National Research Council 1991. Real-time earthquake monitoring: early
warning and rapid response. US National Academy Press, Washington.

**Related Environmental and Geological Issues:** Near-surface
earthquakes can induce a wide range of important and generally
irreversible changes in landscape morphology: including faults and
surface fissure \[see surface displacement\], sand-soil liquefaction,
rockfalls, debris flows and other forms of slope failure \[see slope
failure (landslides)\]. Human activities such as constructing dams and
reservoirs, pumping out or in waste fluids, hydrocarbons and water can
trigger seismic activity in normally aseismic ('quiet') areas. The
social and economic impacts of major earthquakes can be devastating,
particularly in urban areas. A proper building code that sets standards
for construction and maintenance should be based on knowledge of both
seismicity and local ground conditions.

**Overall Assessment:** It is essential to monitor the seismicity of any
tectonically active area so as to avoid or minimize injury to life and
damage to property.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **NATURAL RESOURCE MONITORING PARAMETERS**      | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Shoreline Position**                          | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description**: The position of the shoreline along ocean coasts
and around inland waters (lakes) varies over a broad spectrum of time
scales in response to shoreline erosion (retreat) or accretion
(advance), changes in water level, and land uplift or subsidence \[see
relative sea level; surface displacement\]. Long-term trends in
shoreline position may be masked in the short term by variations over
periods of 0.1-10 years or more, related, for example, to individual
storms, changes in storminess, and El Niño/Southern Oscillation effects.
Shoreline position reflects the coastal sediment budget, and changes may
indicate natural or human-induced effects alongshore or in nearby river
catchments. The detailed shape and sedimentary character of a beach
(e.g. beach slope, cusp dimensions, bar position and morphology, barrier
crest and berm elevation, sediment size and shape) are highly sensitive
to oceanographic forcing, including deep-water wave energy, nearshore
wave transformation, wave setup, storm surge, tides, and nearshore
circulation: morphodynamic adjustments and feedbacks are common.
Qualitative assessments of shoreline morphology can be used as a proxy
for shore-zone processes, partially substituting for more quantitative
measures of shoreline change where these are not available.

**Significance**: Changes in the position of the shoreline affect
transportation routes, coastal installations, communities, and
ecosystems. The effects of shoreline erosion on coastal communities and
structures can be drastic and costly. It is of paramount importance for
coastal settlements to know if local shorelines are advancing,
retreating or stable. Rates of recession as high as 5-10 m/yr have been
measured in many places around the world, and much higher rates have
been recorded locally. Coastal erosion in the USA alone is estimated to
cost \$700 million annually. Floods related to recent storm surges along
the low-lying coasts of the Bay of Bengal have caused as many as 50,000
deaths per event.

**Environment where Applicable**: Ocean coasts, lake shores, estuaries.

**Types of Monitoring Sites**: Cliffs, beaches, coastal dunes and
wetlands \[see dune formation and reactivation; wetlands extent,
structure and hydrology\] and other shoreline settings.

**Method Of Measurement**:

Quantitative: Using conventional ground survey and other methods (simple
rod and tape profiles, levelling, electronic total-station surveys,
airphotos, GPS, analysis of old maps and charts), the following
parameters are commonly monitored:

1\. Width of the dry beach, position of the mean water line, the high
water line, or the base of the beach where well defined. However,
measurements are subject to local variations in water level and sand
storage, and it may take 10 years or more to separate long-term trends
from daily, annual or multi-annual variations.

2\. Changes in position of top and toe of bluffs. These can provide
proxies of shoreline movement, though in the short term they can move in
opposite directions to those of the shoreline.

3\. Changes in position of foreshore and backshore vegetation: note that
the vegetation line can move in the short term in an opposite direction
to that of the shoreline.

4\. Beach profiles along sequential transects normal to the shoreline.
Best for evaluating seasonal or other short-term shoreline movements,
and beach morphology.

To help in understanding why shoreline change is occurring, it can be
helpful to measure:

5\. Water levels, wind speed and direction, storm waves, and coastal
currents; these can be related to shoreline change. Storm surge limits
and other high-water indicators of meteorological or oceanographic
forcing are especially important.

6\. Losses or gains of sediment (sediment budget) in specific coastal
compartments or cells. A sediment surplus is typically associated with
an advancing shoreline, whereas a deficit may lead to shoreline retreat.
The procedure attempts to identify where sediment is coming from and
where it is being deposited (i.e. sources and sinks). Common sources are
coastal rivers, updrift beaches or bluffs, and the inner continental
shelf. Common sinks are coastal dunes, storm washovers, tidal deltas,
accreting beaches, and the inner continental shelf.

Qualitative: Simple and immediate visual assessments of shore morphology
can indicate the state of the shoreline (eroding/accreting). These
should be supplemented by photographs and videos taken from low-flying
aircraft, of the mean or high water line, the limit of vegetation, the
landward limit of washover sedimentation, or the base or top of a
coastal cliff. Simple monitoring can be done by repeated assessments of
change along a particular stretch of shoreline, such as an increase in
the degree of erosion at individual sites or an increase in the number
of eroding sites in a particular region.

1\. The following features indicate contemporary or recent erosion:
scarped or breached dunes; bluffs without talus ramps or toe deposits;
peat, mud or tree stumps in the surf zone; toppled trees along the
shore; narrow beaches; and washover fans. Coasts undergoing severe
erosion are commonly marked by: absence of dunes and vegetation,
presence of a washover apron, tidal channels that extend into the surf
zone, unvegetated bluffs without ramps at their base (active
wave-cutting), and man-made shoreline structures now located offshore.
Actively eroding rocky shorelines are characterized by rock falls,
collapsing caves and seastacks.

2\. The following features indicate accreting or stable coasts: robust
dunes, newly formed beach ridges, wide beaches with well-developed
berms, absence of overwash or dune breaching, well-developed beach
vegetation (berm colonizers, dune grasses and shrubs, healthy forests
extending to shoreline), well-vegetated bluff face and toe, substantial
toes at base of bluffs or cliffs.

3\. Long-term shoreline retreat may be marked by the presence on the
foreshore of material distinct in texture or composition, such as older
relict sediments, backshore peat or shell assemblages underlying
foreshore deposits.

**Frequency of Measurement**: Seasonal, before and after storms.
Semi-annual or annual, once seasonal variability is established.

**Limitations of Data and Monitoring**: Results are site specific,
temporally and spatially discontinuous, and of varying quality.
Historical records are commonly short. Qualitative results can be
misleading, and many methods have severe limitations. Sediment budget
calculations are hampered by lack of accurate data on coastal bathymetry
and topography; map analysis by lack of accurate maps and reliable datum
levels; photo analysis by radial distortion and tilt and by difficulties
in determining high-water lines.

Adjacent shoreline segments may respond differently to the same
environmental conditions. Gravel-dominated coastal systems may exhibit
progressive beach crest growth and sediment sorting that can lead to
increased stability with time or to a growing potential for rapid
destabilization during extreme events. Changes in relative sea level and
in sediment supply are critical factors in coastal evolution and in the
response of shorelines to environmental change. In some cases sediment
supply may be controlled by processes external to the coastal system,
such as glacier-burst floods, changes in ice-marginal drainage, or
artificial river impoundment.

**Possible Thresholds**: Subtle changes in sediment supply or other
factors can shift the balance between shoreline stability or accretion
and shoreline erosion, with significant implications for coastal
ecosystems and settlements.

**Key References**:

Berger, A.R. & W.J.Iams (eds). Geoindicators: Assessing rapid
environmental changes in earth systems. Rotterdam: A.A. Balkema. (see
papers by Forbes & Liverman, Morton, and Young et al.).

Carter, R.W.G. 1988. Coastal environments: an introduction to the
physical, ecological and cultural systems of coastlines. London:
Academic Press.

Carter, R.W.G. & C.D.Woodroffe (eds) 1994. Coastal evolution: Late
Quaternary shoreline morphodynamics. Cambridge: Cambridge University
Press. (especially paper by Cowell and Thom on coastal morphodynamics).

Godschalk, D.R., D.J.Brower & T.Beatley 1989. Catastrophic coastal
storms and hazard mitigation and development management. Raleigh NC:
Duke University Press.

Pilkey, O.H., R.A.Morton, J.T.Kelley & S.Penland 1989. Coastal land
loss. Washington, American Geophysical Union.

**Related Environmental and Geological Issues**: Changes in the
shoreline affect the distribution and functioning of salt marsh,
estuarine and littoral ecosystems, as well as the planning and
management of coastal resources and built structures.

**Overall Assessment**: The shoreline position is perhaps the most
important geoindicator for low-lying coastal communities and islands.
Quantitative methods are best for predicting future shoreline movements.
Qualitative indicators of shoreline position and morphology are
practical, inexpensive, and rapid guides to coastal erosion.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC MONITORING PARAMETERS**              | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Slope Failure (landslides)**                  | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** There are many ways in which slopes may fail,
depending on the angle of slope, the water content, the type of earth
material involved, and local environmental factors such as ground
temperature. Mass movements (landslides, mass wasting) may take place
suddenly and catastrophically, resulting in debris and snow avalanches,
lahars, rock falls and slides, flows (debris, quick clay, loess, and dry
or wet sand and silt). For example, the initial velocity of mudflows can
reach 30m/second in a few seconds, slowing to several m/day. Slower
movements result in slides (debris, rock blocks), topples, slumps (rock,
earth), complex landslides and creep. Landsliding is commonly regarded
as one of the most predictable of geological hazards. Three parameters
are particularly important for monitoring all kinds of mass movements.

1\. Ground cracks are the surface manifestation of a variety of mass
movements. In plan, they are commonly concentric or parallel, and have
widths of a few centimeters and lengths of several meters, which
distinguishes them from the much shorter desiccation cracks \[see desert
surface crusts and fissures\]. The formation of cracks and any increase
in their rate of widening is a common measure of impending slope
failure.

2\. The appearance of and increases in ground subsidence or upheaval is
also a good measure of impending failure.

3\. The area of slope failure is a measure of the extent of landsliding
in any region. Changes over time may both reflect significant
environmental stresses (e.g. deforestation, weather extremes) and
provide important clues about landscape and ecosystem degradation.

Special conditions and processes exist in permafrost terrains.
Landslides and mudflows of permafrost regions are mobilized and shaped
by the freezing and thawing of pore water in the active layer, the base
of which acts as a shear discontinuity. Failure here can occur on slopes
as low as 1o. Gelifluction (a form of solifluction, the slow downslope
movement of waterlogged soil and surficial debris) is the regular
downslope flow or creep of seasonally frozen and thawed soils. Gentle to
medium slopes with blankets of loose rock fragments overlying frozen
ground may be subject to mass movements such as rock glaciers and rock
streams or kurums \[see frozen ground activity\]. Catastrophic slope
failure here can expose new frozen ground, setting off renewed mass
wasting.

Climate change may accelerate or slow the natural rate of slope failure,
through changes in precipitation or in the vegetation cover that binds
loose slope materials: wildfires can also promote mass movements by
destroying tree cover. However, it is difficult to generalize where
information is lacking on the present distribution and significance of
landslides, and because many parameters, in addition to climate change,
contribute to slope stability.

**Significance:** Thousands of people are killed each year by
landslides: in China and Peru, tens of thousands of deaths have resulted
from single landslides. Annual property damage from landslides worldwide
is estimated in the tens of billions of dollars, with more than \$1.5
billion in annual losses in the USA alone. There are innumerable small
to medium-size slope failures that cumulatively impose costs to society
as great or greater than the large infrequent catastrophic landslides
that draw so much attention. Damage to ecosystems has not generally been
documented, but landslides may destroy habitats, for example by blocking
streams and denuding slopes.

**Environment where Applicable:** Landslides are most common on moderate
to steep slopes worldwide, but even gentle and flat-lying slopes may
fail where adjacent to steep slopes, rivers, and other bodies of water.
The risk of failure is generally greater where rocks are highly
fractured, or where there are surficial soils, clays and silts that are
liable to liquefaction. Many pre-existing landslides are re-activated,
even under conditions that the original slope, prior to first failure,
could have resisted.

**Types of Monitoring Sites:** The highest part (crown) of landslides
and other potential failures is generally the most important place for
monitoring cracks, subsidence and sagging. Upheaval or buckling
generally begins in the toe area. As failure progresses and the slide or
flow develops, cracks and ground subsidence may form at any point
including the toe: one landslide in Japan formed cracks and uplifted a
railroad tunnel in the toe area over 1 km away and on the other side of
a river from the crown.

**Method of Measurement:** Surface methods for measuring the development
of cracks, subsidence and uplift include repeated conventional
surveying, installation of various instruments to measure movements
directly, and tiltmeters to records changes in slope inclination near
cracks and areas of greatest vertical movements. Subsurface methods
include installation of inclinometers and rock noise instruments to
record movements near cracks and other areas of ground deformation,
bucket auger holes large enough to accommodate a person who locates,
records and monitors cracking and deformation at depth, and geophysical
techniques for locating shear surfaces throughout the landslide area.
The areal extent of landsliding over large areas is most effectively
determined using air photos. Satellite images may be helpful in
identifying large landslides and in noting changes in soil and
vegetation cover that may be associated with landsliding. Conversion of
landslide extent from photos to a digital database will permit easy
measurement of areal changes for each type of landslide deposit. At
higher latitudes, color infrared photos at scales of 1:25,000 to
1:50,000 are best for most landslides, if taken in early spring or late
fall (no snow or deciduous leaves) when sun angle is high and shadows
are at minimum.

**Frequency of Measurement:** The frequency of monitoring will largely
be dictated by changes in rate of crack propagation and ground
deformation and by the degree of potential damage if the slope fails.
For example, urban or industrial areas of high risk and rapid change
will require continuous monitoring and, probably, the installation of
automatic warning devices such as sirens and barriers. Areas of low risk
and very slow development of cracks and ground deformation can be
examined much less frequently. Critical periods for monitoring are
during and immediately after intense rains and rapid snowmelt: real-time
monitoring of rainfall from telemetered rain gauges and precipitation
forecasts may be very important. Once a comprehensive and reliable
baseline of past and present landslide activity has been established,
the measurement should be repeated after hurricanes and other
significant snowfall/snowmelt and rainfall events, or after fires,
deforestation or human activities that extensively modify the land
surface. If little activity has taken place in a particular area,
re-assessment can be delayed for several years or more.

**Limitations of Data and Monitoring:** The factors influencing slope
stability are numerous and often complex, and monitoring of cracks may
provide little insight in dealing with particular landslides. Many
cracks form and are followed by landsliding within seconds, as do many
areas with active subsidence and upheaval, so that monitoring these
slopes will not help in warning local residents. Other landslides may
form cracks, subside or buckle over long periods of time and then fail
suddenly with little warning. Other methods may be more useful for
predicting failure, such as regional landslide hazard mapping, rainfall
monitoring, and monitoring of pore water pressure. In assessing changes
in areal extent, the skill of the interpreter, the quality of the air
photography, and factors such as cloud and vegetation cover, haze, and
sun angle may greatly limit the usefulness of the data. Many landslides
cannot be detected on available air photos, and if their scale is too
large, the expense and time required to analyze them may be prohibitive.
Radar images may be needed for tropical area where vegetation cover is
extensive. Most of the features used to identify landslides are too
small be to recognized on currently available satellite images.

**Possible Thresholds:** Slope failure takes place when the critical
slope angle is exceeded. The angle depends on the frictional properties
of the slope material and increases slightly with the size and
angularity of the fragments. Dry, cohesionless material will come to
rest on similar material when the angle of repose ranges generally
between 33o and 37o. For wet, cohesive materials underlain by frozen
ground, downslope movement may occur on slopes as low as 1o. A related
threshold for permafrost is the freeze-thaw transition \[see frozen
ground activity\]. In humid areas of unstable slopes, the cumulative and
anticipated rainfall may reach empirical threshold values, at which time
warnings of impending slope failure should be issued.

**Key References:**

Berger, A.R. & W.J.Iams (eds). Geoindicators: Assessing rapid
environmental changes in earth systems. Rotterdam: A.A. Balkema (see
papers by Nesje, Rasch et al., Romanovskii et al.).

Brabb, E.E. 1984. Innovative approaches to landslide hazard and risk
mapping. Proceedings of IV International Symposium on Landslides 1:
307-324.

Brabb, E.E. and B.L.Harrod 1989. Landslides - extent and economic
significance. Rotterdam: Balkema.

Casale, R., R.Fantechi & J.C.Flageollet 1995. Temporal occurrence and
forecasting of landslides in the European Community. European
Commission, 2 vols.

Jones, D.K.C. & E.M.Lee 1994. Landsliding in Great Britain. London: HM
Stationery Office

Novosad, S. & P.Wagner (eds) 1993. Landslides. Proceedings of 7th
International Conference on Landslides. Rotterdam:Balkema. (especially
papers by Glawe et al. and Moriwaki).

Keefer, D.K. 1987. Real-time landslide warning during heavy rainfall.
Science, 238: 921-925.

Selby, M.J. 1993. Hillslope materials and processes. 2nd edition.
Oxford: Oxford University Press.

Schuster, R.L. & R.J.Krizek (eds) 1978. Landslides, analysis and
control. U.S. National Academy of Sciences Transportation Research Board
Special Report 176. (especially papers by Varnes, and Wilson &
Mikkelson - N.B. A new edition is in preparation).

**Related Environmental and Geological Issues**: Removal of forest and
plant cover (fire, deforestation); land clearing and accelerated soil
erosion in sloping terrain; potential destruction of ecosystems affected
by slope failure.

**Overall Assessment:** Slope failure is one of the most widespread
causes of land disturbance, so that the initiation and development of
landslides should be closely monitored.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Soil and Sediment Erosion**                   | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**BRIEF DESCRIPTION:** Erosion, the detachment of particles of soil and
surficial sediments and rocks, occurs by hydrological (fluvial)
processes of sheet erosion, rilling and gully erosion, and through mass
wasting and the action of wind \[see sediment geochemistry and
stratigraphy; stream sediment storage and load; wind erosion\]. Erosion,
both fluvial and eolian (wind) is generally greatest in arid and
semi-arid regions, where soil is poorly developed and vegetation
provides relatively little protection. Where land use causes soil
disturbance, erosion may increase greatly above natural rates. In
uplands, the rate of soil and sediment erosion approaches that of
denudation (the lowering of the Earth\'s surface by erosional
processes). In many areas, however, the storage of eroded sediment on
hillslopes of lower inclination, in bottomlands, and in lakes and
reservoirs, leads to rates of stream sediment transport much lower than
the rate of denudation.

When runoff occurs, less water enters the ground, thus reducing crop
productivity. Soil erosion also reduces the levels of the basic plant
nutrients needed for crops, trees and other plants, and decreases the
diversity and abundance of soil organisms. Stream sediment degrades
water supplies for municipal and industrial use, and provides an
important transporting medium for a wide range of chemical pollutants
that are readily sorbed on sediment surfaces. Increased turbidity of
coastal waters due to sediment load may adversely affect organisms such
as benthic algae, corals and fish.

**Significance:** Soil erosion is an important social and economic
problem and an essential factor in assessing ecosystem health and
function. Estimates of erosion are essential to issues of land and water
management, including sediment transport and storage in lowlands,
reservoirs, estuaries, and irrigation and hydropower systems. In the
USA, soil has recently been eroded at about 17 times the rate at which
it forms: about 90% of US cropland is currently losing soil above the
sustainable rate. Soil erosion rates in Asia, Africa and South America
are estimated to be about twice as high as in the USA. FAO estimates
that 140 million ha of high quality soil, mostly in Africa and Asia,
will be degraded by 2010, unless better methods of land management are
adopted.

**Environment where Applicable**: Potentially any land surface, but
especially where disturbed for any reason, and sloping areas mantled
with soil or loose sediment.

**Types of Monitoring Sites:** Representative sites in uplands and
bottomlands.

**Method of Measurement:** Standard techniques, using erosion pins to
detect soil creep or sheet and rill erosion, painted-rock lines and
other sediment tracers to determine soil movement, cliff-recession and
headcut markers, Young pits, repeated profile and slope measurements,
and repeat photography using reference points. Repeat measurements of
water and sediment collected in permanently installed hillslope troughs
provide seasonal, annual and longer-term estimates of erosion and
storage along hillslope profiles. Rates of soil erosion can be estimated
using erosion-prediction equations developed during the last four
decades. Among these algorithms are the Universal Soil Loss Equation
(and its recent update the Revised Universal Soil Loss Equation), the
Water Erosion Prediction Project model, and the European Soil Erosion
Model.

**Frequency of Measurement**: Seasonally, annually to once per decade,
depending on local conditions and parameter measured.

**Limitations of Data and Monitoring:** Erosion is very irregularly
distributed in time and space, and it is difficult to determine how
representative a particular site is.

**Possible Thresholds:** Gully erosion may become pronounced following
cyclic periods of local to regional deposition, during which a critical
threshold slope for drainageways is developed. When these threshold
slopes are exceeded, the bottomlands adjacent to channels or
drainageways may become unstable and subject to erosion. The slope angle
above which instability occurs depends on local conditions of water and
sediment distribution and on particle sizes of the sediment subject to
transport. One result is a natural alternation of gully filling and
evacuation of sediment, especially in arid areas over decadal periods.
Another result may be intense rill and gully erosion where land use has
reduced or destroyed soil cover (vegetation, litter, rock fragments) or
has increased runoff and its erosive effects.

**Key References:**

Commission on Applied Geomorphology, 1967. Field methods for the study
of slope and fluvial processes. Revue de Geomorphologie dynamique:
152-58.

Foster, G.R., & L.J.Lane, 1987. User requirements - USDA Water Erosion
Prediction Project (WEPP). NSERL Report 1, U.S. Department of
Agriculture, Agricultural Research Service, West Lafayette, IN: National
Soil Erosion Research Laboratory.

Osterkamp, W.R., W.W.Emmett & L.B.Leopold 1991. The Vigil Network - a
means of observing landscape change in drainage basins. Hydrological
Sciences Journal, 36:331-344.

Osterkamp, W.R. & S.A.Schumm 1996. Geoindicators for river and
river-valley monitoring. In Berger, A.R. & W.J.Iams (eds).
Geoindicators: Assessing rapid environmental changes in earth
systems:83-100. Rotterdam: A.A. Balkema (see also paper by Lancaster).

Renard, K.G., G.R.Foster, G.A.Weesies, D.K.McCool & D.C.Yoder 1995.
Predicting soil erosion by water: a guide to conservation planning with
the revised universal soil loss equation (RUSLE). Agricultural Handbook
703, Washington DC: U.S. Department of Agriculture.

Schumm, S.A., M.O.Harvey & C.C.Watson 1984. Incised channels:
morphology, dynamics and control. Littleton, Colorado: Water Resources
Publications.

Wolman, W.G. & H.C.Riggs 1990. Surface water hydrology. The Geology of
North America vol. 0-1, Boulder, Colorado: Geological Society of
America. (especially paper by Meade, R.H., T.R.Yuzyk & T.J.Day, Movement
and storage of sediment in rivers of the United States and Canada,
p255-280).

**Related Environmental and Geological Issues**: Land degradation.
Deposition of eroded soil particles with sorbed contaminants can
endanger entire ecosystems along continental margins, in estuaries,
wetlands and bottomlands, and on other areas of low slope angle. Soil
erosion both affects and is affected by vegetation and crop cover.

**Overall Assessment:** Monitoring soil and sediment erosion is of the
greatest importance in determining rates of land degradation.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Soil Quality**                                | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Soils vary greatly in time and space. Over
time-scales relevant to geoindicators, they have both stable
characteristics (e.g. mineralogical composition and relative proportions
of sand, silt and clay) and those that respond rapidly to changing
environmental conditions (e.g. ground freezing). The latter
characteristics include soil moisture and soil microbiota (e.g.
nematodes, microbes), which are essential to fluxes of plant nutrients
and greenhouse gases. The soils of boreal regions are estimated to hold
the equivalent of some 60% of the current atmospheric carbon: long-term
warming is expected to increase decomposition and drying, thus
potentially releasing huge volumes of methane and CO2. Recent research
shows that the Alaskan tundra no longer serves as a carbon sink, but has
begun to release significant quantities of carbon.

Most soils resist short-term climate change, but some may undergo
irreversible change such as lateritic hardening and densification,
podsolization, or large-scale erosion. Soil properties and climatic
variables such as mean annual rainfall and temperature can be related by
mathematical functions known as climofunctions.

Chemical degradation takes place because of depletion of soluble
elements through rainwater leaching, overcropping and overgrazing, or
because of the accumulation of salts precipitated from rising
groundwater or irrigation schemes. It may also be caused by sewage
containing toxic metals, precipitation of acidic and other airborne
contaminants, as well as by persistent use of fertilizers and
pesticides. A widespread problem is the retention in the soil organic
matter and clay minerals of potentially toxic metals and radionuclides
(e.g. Cu, Hg, Pb, Zn, 226Ra, 238U). These and other chemical components
may be catastrophically released as what are commonly referred to as
'chemical time bombs' where the pH of the soil is decreased by
acidification or where other environmental disturbances (e.g. erosion,
drought, land use change) intervene. Soils also act as a primary barrier
against the migration of organic contaminants into groundwater. Key
indicators are pH, organic matter content, sodium absorption ratio,
cation exchange capacity, and cation saturation.

Physical degradation results from land clearing, erosion and compaction
by machinery. Soil structure may be altered so that infiltration
capacity and porosity are decreased, and bulk density and resistance to
root penetration are increased. Such soils have impeded drainage and are
quickly saturated: the resultant runoff can cause accelerated erosion
and transport of pollutants such as pesticides \[see soil and sediment
erosion\]. The key soil indicators are texture (especially clay
content), bulk density, aggregate stability and size distribution, and
water-holding capacity.

**Significance:** As one of Earth\'s most vital ecosystems, soil is
essential for the continued existence of life on the planet. As sources,
stores, and transformers of plant nutrients, soils have a major
influence on terrestrial ecosystems. Soils continuously recycle plant
and animal remains, and they are major support systems for human life,
determining the agricultural production capacity of the land. Soils
buffer and filter pollutants, they store moisture and nutrients, and
they are important sources and sinks for CO2, methane and nitrous
oxides. Soils are a key system for the hydrological cycle \[see
groundwater chemistry in the unsaturated zone\]. Soils also provide an
archive of past climatic conditions and human influences.

**Environment where Applicable:** Any land surface, especially
agricultural and afforested areas.

**Types of Monitoring Sites:** Undisturbed lands, such as uncultivated
grasslands and forests, can provide reference sites for comparison with
changes in soils subject to human activities related to forestry,
agriculture and urbanization.

**Method of Measurement:** Routine physical, chemical and morphological
descriptions. Chemical degradation can also be monitored by analysis of
groundwater \[see groundwater quality\].

**Frequency of Measurement**: Every 1-10 years

**Limitations of Data And Monitoring:** Soils can vary considerably in
chemical, physical and biological properties, both vertically through
the soil profile, and horizontally, so that it may be difficult to
select representative sites for monitoring.

**Possible Thresholds**: Threshold values for chemical and physical
degradation vary according to the usage of soils for agricultural,
forestry, waste disposal, and other purposes.

**Key References:**

Acton, D.F. & L.J.Gregorich (eds.) 1995. The health of our soils -
toward sustainable agriculture in Canada. Centre for Land and Biological
Resources Research, Ottawa: Agriculture and Agri-Food Canada.

Batjes, N.H. & E.M.Bridges 1992. A review of soil factors and processes
that control fluxes of heat, moisture and greenhouse gases. Technical
paper 23, Wageningen: International Soil Reference and Information
Center.

Klute, A. (ed) 1986. Physical and mineralogical methods. Methods of soil
analysis: Part 1. American Soil Science Society Agronomy Monograph 9.

Page, A.L., R.H.Miller & D.R.Keeney 1986. Chemical and microbiological
properties. Methods of soil analysis: Part 2. American Soil Science
Society Agronomy Monograph 9.

Peirce, F.J. & W.E.Larson 1996. Quantifying indicators for soil quality.
In Berger, A.R. & W.J.Iams (eds). Geoindicators: Assessing rapid
environmental changes in earth systems:309-321. Rotterdam: A.A. Balkema.

Ringrose-Voase, A.J. & G.S.Humphrey (eds) 1994. Soil micromorphology:
studies in management and genesis. Amsterdam: Elsevier.

**Related Environmental and Geological Issues:** Accelerated
contamination of groundwater can occur if the sorption capacity of soils
for potentially toxic chemicals is exceeded by elevated levels from
human activities. There is an extensive body of knowledge dealing with
physical and chemical changes in soils under cultivation.

**Overall Assessment:** Soil quality is a sensitive indicator of natural
and human-induced perturbations of the environment: changes may affect
the quality of surface and groundwater. Monitoring changes in soil
properties can assist in predicting the future value of soils for
agricultural, forestry and other purposes.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Stream Channel Morphology**                   | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Alluvial streams (rivers) are dynamic landforms
subject to rapid change in channel shape and flow pattern. Water and
sediment discharges determine the dimensions of a stream channel (width,
depth, and meander wavelength and gradient). Dimensionless
characteristics of stream channels and types of pattern (braided,
meandering, straight) and sinuosity are significantly affected by
changes in flow rate and sediment discharge, and by the type of sediment
load in terms of the ratio of suspended to bed load \[see stream
sediment storage and load\]. Dramatic changes in stream bank erosion
within a short time period indicate changes in sediment discharge.
Because changes in alluvial channel cross-section, especially width, may
indicate change in the discharge characteristics of the stream, known
discharges can be expressed as a simple power relation with channel
width (Q = aWb, where Q = discharge, a = a coefficient, W = channel
width, and b is an exponent). At ungauged stream sites, therefore,
measurements of channel morphology can lead to indirect estimates of
discharge, which, if varying with time, may indicate changes in mean
discharge or in the occurrence of floods at specific recurrence
intervals.

**Significance:** Channel dimensions reflect magnitude of water and
sediment discharges. In the absence of hydrologic and streamflow
records, an understanding of stream morphology can help delineate
environmental changes of many kinds. Changes in stream pattern, which
can be very rapid in arid and semi-arid areas, place significant limits
on land use, such as on islands in braided streams and meander plains,
or along banks undergoing erosion.

**Environment where Applicable:** Alluvial streams occupying bottomlands
comprised of terraces and flood plains.

**Types of Monitoring Sites:** Characteristic stream reaches

**Method of Measurement**: Repeated ground and/or aerial surveys of
channel patterns and cross-sections, using streamflow gauges, channel
cross-section monuments, and other automated and manual loggers.

**Frequency of Measurement:** Depends on observed rate of change, but no
less than once every 5 years.

**Limitations of Data and Monitoring:** It is difficult to gauge stream
change without historical records. Floods may destroy observation sites.

**Possible Thresholds:** Meander amplitude can increase until cutoff is
inevitable. Stream variability involving changes between straight,
meandering, and braided forms can reflect changes on valley gradients as
a result of active tectonics and tributary influences.

**Key References:**

Chang, H.H. 1988. Fluvial processes in river engineering. New York: John
Wiley & Sons.

Osterkamp, W.R. & E.R.Hedman 1982. Perennial-streamflow characteristics
related to channel geometry and sediment in Missouri River basin. U.S.
Geological Survey Professional Paper 1241.

Osterkamp, W.R. & S.A.Schumm 1996. Geoindicators for river and
river-valley monitoring. In Berger, A.R. & W.J.Iams (eds).
Geoindicators: Assessing rapid environmental changes in earth
systems:83-100. Rotterdam: A.A. Balkema.

Schumm, S.A. & B.R.Winkley (eds) 1994. The variability of large alluvial
rivers. New York: American Society of Civil Engineers Press.

**Related Environmental and Geological Issues:** Condition of riverine
ecosystems; stability of islands and channels, and jurisdictional
boundaries defined by rivers.

**Overall Assessment:** Monitoring stream channel morphology can be
useful when no data are available on sediment load, flow rates and other
hydrologic parameters.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Stream Sediment Storage and Load**            | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** The load (discharge, tonnes/year) or yield
(tonnes/km2/year) of sediment (in suspension and as bed load of sand and
gravel) through stream (river) channels reflects upland erosion within
the drainage basin and change in storage of sediment in alluvial
bottomlands \[see soil and sediment erosion\]. In turn, this is
influenced by climate, vegetation, soil and rock type, relief and slope,
and human activities such as timber harvesting, agriculture, and
urbanization. Much of the sediment eroded from upland areas is deposited
(stored) on lower hillslopes, in bottomlands, and in lakes and
reservoirs. In terms of sediment budget, net erosion = total
denudation - sediment storage + channel erosion, where denudation is a
measure of regional upland erosion. Flash floods in ephemeral desert
streams may transport very large sediment loads, accounting for
unforeseen sedimentation problems in dryland stream reservoirs.

**Significance:** Sediment load determines channel shape and pattern
\[see stream channel morphology\]. Changes in sediment yield reflect
changes in basin conditions, including climate, soils, erosion rates,
vegetation, topography and land use. Fluctuations in sediment discharge
affect a great many terrestrial and coastal processes, including
ecosystem responses, because nutrients are transported together with the
sediment load. For example, to reproduce effectively, salmon and trout
need gravel stream beds for spawning and egg survival; silt and clay
deposits formed by flooding or excessive erosion can destroy these
spawning beds. Stream deposits also represent huge potential sinks for,
and sources of, contaminants.

**Environment where Applicable:** Fluvial systems

**Types of Monitoring Sites**: Stream channels where evidence of erosion
or sedimentation is available and where local observations can be
extrapolated to larger areas.

**Method of Measurement:** Periodic sampling of suspended sediment to
determine its concentration, combined with periodic coring of bed load
to determine the rate of storage, and measurement of bedload flux
(discharge). Sampling should be carried out at enough sites to provide
estimates of volume, and should be supported by direct examination of
stream margins, cutbank exposures and overbank deposits. Where more
quantitative data are not available, studies of changes in biomass
distribution (especially woody plants) can provide reliable qualitative
measures of hydrologic and geomorphic events over the past several
hundred years.

**Frequency of Measurement:** Daily, or often enough to obtain a
continuous record of changes. Measurements of sediment storage at least
once every 5 years.

**Limitations of Data And Monitoring:** Bedload is difficult and
expensive to measure, and is rarely monitored. The deepest parts of
streams are hard to sample. The effectiveness of stream sediment storage
and load as an indicator is strongly dependent on a well-designed,
systematic monitoring network. Sediment discharge may increase or
decrease due to natural cycles of stream development under conditions of
stable climate.

**Possible Thresholds**: NA

**Key References**:

Guy, H.P. & V.W.Norman 1970. Field methods for measurement of fluvial
sediment. US Geological Survey Techniques of Water Resources
Investigation, Book 3, Chapter C-2.

Osterkamp, W.R. & S.A.Schumm 1996. Geoindicators for river and
river-valley monitoring. In Berger, A.R. & W.J.Iams (eds).
Geoindicators: Assessing rapid environmental changes in earth
systems:83-100. Rotterdam: A.A. Balkema.

Vanoni, V.A. (ed) 1975. Sedimentation engineering. New York: American
Society of Civil Engineering Press.

Wolman, W.G. & H.C.Riggs 1990. Surface water hydrology. The Geology of
North America Volume 0-1, Boulder, Colorado: Geological Society of
America. (especially paper by Meade, R.H., T.R.Yuzyk & T.J.Day Movement
and storage of sediment in rivers of the United States and Canada,
p255-280).

**Related Environmental and Geological Issues:** Stream sediment storage
and load affects virtually all environmental issues in drainage basins
and along coastlines fed by stream sediment. Stream sediments may
affect, for example, the health of aquatic organisms, and the silting-up
of reservoirs and harbours. They may also store chemical contaminants in
'chemical time bombs' which can be subsequently released into the
environment by flood events or other disturbances.

**Overall Assessment:** Stream sediment storage and load is of extreme
importance in determining the transport of erosion products through and
out of drainage basins.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Subsurface Temperature Regime**               | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Temperatures in boreholes a few hundred metres
deep can be an important source of information on recent climatic
changes, because the normal upward heat flow from the Earth\'s crust and
interior is perturbed by the downward propagation of heat from the
surface. As temperature fluctuations are transmitted downward, they
become progressively smaller, with shorter-period variations attenuating
more rapidly than longer ones. Although seasonal oscillations may be
undetectable below about 15 m, century-long temperature records may be
observed to depths of 150 m or so. Bedrocks thus selectively retain the
long-term trends required for reconstructing climate change.

The surface temperature is strongly affected by local factors such as
thickness and duration of snow cover, type of vegetation, properties of
organic soil layers, depth to the water table, and topography. It
influences, in turn, a wide range of ground and surface processes,
particularly in the near-surface portions of permafrost \[see frozen
ground activity\]. Below the active layer, where ground temperature
fluctuates seasonally as thawing and freezing take place, long-term
temperature variations may be recorded. Here, repeated measurements of
soil temperature at fixed locations can reveal both the long-term
dynamics of seasonally frozen ground and long-term climatic
fluctuations, though the conversion of ground temperature to climate
history is a complex matter. In the northern Canadian prairies ground
temperatures have risen by 2oC and permafrost has retreated northwards
by 100 km in the past 50 years. In contrast, permafrost temperatures
have fallen in northern Quebec in recent years.

**Significance:** The thermal regime of soils and bedrocks exercises an
important control on the soil ecosystem, on near-surface chemical
reactions (e.g. involving groundwater), and on the ability of these
materials to sequester or release greenhouse gases. It may affect the
type, productivity and decay of plants, the availability and retention
of water, the rate of nutrient cycling, and the activities of soil
microfauna. It is also of major importance as an archive of climate
change, indicating changes in surface temperature over periods of up to
2-3 centuries, for example in regions without a record of past surface
temperatures. In permafrost, the ground temperature controls the
mechanical properties of the soils, especially during the freeze-thaw
transition in the active layer.

**Environment where Applicable:** Any terrestrial area, but particularly
in permafrost regions.

**Types of Monitoring Sites:** Remote sites no more than 500-1000 km
apart and away from obvious human disturbances, bodies of surface water,
or areas of high geothermal flow where the ground cover is left
undisturbed. The best results are obtained from measurements in
relatively impermeable bedrocks or where there has been minimal
groundwater movement. To ensure a good representation of climate-induced
change, measurements should be made in clusters of boreholes drilled
specifically for this purpose.

**Method Of Measurement:** Many parameters must be measured, and many
factors need to be considered when converting the signal to changes in
surface temperature. Temperatures must be accurately measured
(±millidegrees) in boreholes, using thermocouples, thermistors,
thermoresistors and other measuring devices. Automated data loggers are
most convenient for repeated measurements.

**Frequency of Measurement:** At least once every 5 years for deep
boreholes, more frequently (as often as twice daily) for near-surface
temperatures in permafrost.

**Limitations of Data And Monitoring:** The thermal coupling of the
Earth\'s surface to the atmosphere is complex, and the temperature
signal recorded in the near surface is a filtered version of changes in
surface climate. Physical movements in the active layer of permafrost
regions complicate the picture \[see frozen ground activity\], as do the
effects of snow cover and vegetation in temperate and tropical areas,
and human activities such as urbanization, agriculture or deforestation.
Moreover local topography, precipitation, hydrology and vegetation can
mask the downward propagation of atmospheric temperatures. The
installation of bore-holes disturbs the natural temperature regime,
which should be allowed to recover before monitoring begins.

**Possible Thresholds:** In near-surface permafrost, the freeze-thaw
threshold, which may vary in temperature according to soil and water
salinity, controls a wide range of surficial (periglacial) processes
\[see frozen ground activity\].

**Key References:**

Lachenbruch, A.H. & B.V.Marshall 1986. Changing climate: geothermal
evidence from permafrost in the Alaskan Arctic. Science 234: 689-696.

Lewis,T. (ed.), 1992. Climatic change inferred from underground
temperatures. Global and Planetary Change 6:71-281.

Williams, P.J. & M.W.Smith 1989. The frozen Earth - fundamentals of
geocryology. Cambridge: Cambridge University Press.

**Related Environmental and Geological Issues:** Climate change,
groundwater flow. Changes in near-surface ground temperature may affect
soil fauna and sensitive surface vegetation.

**Overall Assessment:** The subsurface temperature regime is a direct
measure of ground temperature history. It constitutes a very important
indicator of thermal change in the periglacial environment, in soils
(e.g. due to past deforestation, draining of wetlands), and in climate.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Surface Displacement**                        | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** In many regions the Earth\'s surface in many
regions is subject to small but important displacements (uplift,
subsidence, lateral movement, rotation, distortion, dilation) that
affect elevation and horizontal position. These movements result from
active tectonic processes within the Earth, collapse into underground
cavities, or the compaction of surficial materials. Sudden movements may
be caused by faulting associated with earthquakes \[see seismicity\],
and from the collapse of rock or sediment into natural holes in soluble
rocks (e.g. salt, gypsum, limestone \[see karst activity\]), or into
cavities produced by mining of near-surface rocks (especially coal) and
solution-mining of salt. Slower local subsidence may also be induced by:
fluid withdrawal (gas, oil, groundwater, geothermal fluids);
densification or loss of mass in peat being developed for agriculture;
drainage of surface waters from wetlands, which can cause oxidation,
erosion and compaction of unconsolidated soils and sediments \[see
wetlands extent, structure and hydrology\]; and filtration of surface
water through porous sediments such as loess. On a much larger scale,
the land surface elevation responds slowly to plate movements,
compaction of sedimentary basins, and glacial rebound.

In tectonically active mountains, uplift may be as much as 20 mm/year.
Although vertical crustal movements of continental platforms may range
from less than 1 mm/1000 years, rates of 8-9 mm/year have been measured
around Churchill, Manitoba, near the centre of the former Laurentide ice
sheet. In California, groundwater pumping in the San Joaquin Valley
between 1925 and 1967 led to land subsidence of up to 9 m, and oil
withdrawal at Long Beach caused part of the city to subside 9.5 m. The
outflow of geothermal fluids has caused up to 4.5 m subsidence at
Wairaki, New Zealand. Surface subsidence due to sediment compaction in
the Nile Delta ranges up to 50 mm/year, and parts of central California
near the San Andreas fault have moved laterally as much as 3.2 cm/yr
over the past two decades. Large-scale lateral movements of tectonic
plates may average as much as 7 cm/year and more: the Pacific plate is
now converging on the Tonga Ridge near Samoa at rates of up to 24
cm/year.

Fissures and faults can develop suddenly during earthquakes and as a
result of volcanic processes and landsliding, or more slowly as a result
of differential compaction during subsidence. In arid and semi-arid
terrains, fissures up to several km long and a few cm wide may be
rapidly eroded by surface run-off to gullies, some as much as 1-2 m wide
and 2-3 m deep. In China, surface cracks due to fault growth have been
observed to extend laterally at rates well over 100 m per year. In the
USA, surface fault scarps have been noted up to 16 km long and 1 m or
more high, growing vertically by aseismic creep at rates up to 60 mm/yr.
Regional shortening of 15 cm over a distance of 50 km was measured in
Japan prior to an earthquake in April, 1995, following which the
shortened distance returned to normal.

**Significance:** Most Surface Displacements Have But Minor Effects On
Landscapes And Ecosystems. However, there are exceptions, such as where
drainage channels are suddenly displaced by faults, or where
seismically-induced uplift raises intertidal ecosystems above sea-level.
Moreover, extraction of fluids beneath urban areas can induce land
subsidence (as in Bangkok, Mexico City, Shanghai, and Venice) and cause
flooding, especially of coastal communities near sea-level. Subsidence
damages buildings, foundations and other built structures: in the
Houston-Galveston area of Texas, movements on more than 80 surface
faults due to regional subsidence have caused millions of dollars of
property damage.

**Environment where Applicable:** Tectonically active areas (active
fault zones, areas of high seismicity), areas formerly covered by ice
sheets, and areas where subsurface fluids are being withdrawn.

**Types of Monitoring Sites:** Active fault zones, reservoirs, coastal
communities, deltas, urban areas extracting groundwater, oil or gas.

**Method of Measurement:** Repeated precise levelling and ground
surveys, gravity determinations, and in coastal zones tide-gauge
records. Standard geodetic techniques, especially using GPS and laser
range finders. Archaeological studies of former coastal settlements now
below or substantially above sea level.

**Frequency of Measurement:** Depends on the movement taking place

**Limitations of Data and Monitoring:** The sudden collapse of the
ground surface in karst terrain or above mined cavities, and surface
movements due to earthquake faulting are not generally predictable.

**Possible Thresholds:** NA

**Key References:**

Holzer, T.L. (ed) 1984. Man-induced land subsidence. Boulder, CO:
Geological Society of America, Reviews in Engineering Geology VI.

Johnson, A.I. (ed) 1991. Land subsidence. Proceedings of 4th
International Symposium on Land Subsidence. International Association of
Hydrological Sciences Publication 200.

National Research Council 1986. Active Tectonics. National Academy
Press, Washington.

**Related Environmental and Geological Issues:** Surface flooding in
subsiding areas, damage to built structures, changes to hydrological
systems. Rapid, warping of the ground surface may be a sign of impending
sudden stress release, a precursor of an earthquake or, in an area of
active volcanicity, an eruption.

**Overall Assessment:** Displacements of the ground surface can be used
to assess and warn of environmental problems, especially in coastal
areas and in areas liable to subsidence from bedrock solution, mining
and fluid extraction.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | # GEOLOGIC RESOURCE MONITORING PARAMETERS       | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Volcanic Unrest**                             | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** Eruptions are almost always preceded and
accompanied by volcanic unrest, indicated by variations in the
geophysical and geochemical state of the volcanic system. Such
geoindicators commonly include changes in seismicity, ground
deformation, nature and emission rate of volcanic gases, fumarole and/or
ground temperature, and gravity and magnetic fields. Volcanic unrest can
also be expressed by changes in temperature, composition, and level of
crater lakes, and by anomalous melting or volume changes of glaciers and
snow fields on volcanoes. When combined with geological mapping and
dating studies to reconstruct comprehensive eruptive histories of
high-risk volcanoes, these geoindicators can help to reduce
eruption-related hazards to life and property. However, not all volcanic
unrest culminates in eruptions: in many cases the unrest results in a
failed eruption in which the rising magma does not breach the surface
and erupt.

**Significance:** Natural hazards associated with eruptions of the
world\'s 550 or so historically active volcanoes pose a significant
threat to about 10% of the world\'s population, especially in
densely-populated circum-Pacific regions. By the year 2000, more than
half a billion people will be at risk. Before 1900, two indirect
hazards - volcanogenic tsunamis and post-eruption disease and
starvation - accounted for most of the eruption-associated human
fatalities. In the 20th century, however, direct hazards related to
explosive eruptions (e.g. pyroclastic flows and surges, debris flows,
mudflows) have been the most deadly hazards. Lava flows can cause great
economic loss from property damage and decreased agricultural
productivity, but they rarely cause deaths.

**Environment where Applicable:** Most active volcanic systems are
located along or near divergent and convergent boundaries between the
Earth\'s tectonic plates. However, some volcanoes (e.g. Hawaii) occur
thousands of kilometers from the nearest plate boundary and result from
melting and eruptive processes associated with the passage of a tectonic
plate over a fixed thermal anomaly (or hotspot) in the mantle.

**Types of Monitoring Sites:** Geologically young volcanic regions
containing active or potentially active volcanoes, subaerial or
submarine (including the deep ocean floor). Diagnostic monitoring sites
commonly include active vents and fumaroles, crater lakes, and areas of
ground cracking. Ideally the sites should be distributed over the entire
volcanic system, to monitor both the summit and flank areas of eruptive
centers.

**Method of Measurement:** Optimum monitoring of volcanic unrest must be
based on a combination of geophysical, geodetic and geochemical methods,
rather than reliance on any single technique. These involve a networks
of monitoring sites at key locations around a volcanic center at which
repeated measurements are made of horizontal and vertical ground
displacements (borehole strainmeter, laser distance measurements,
gravimeter, tiltmeter, GPS observations), seismicity (automatic event
recording, 3-component and broad band seismometry, and special array
techniques), and a wide range of geochemical parameters.

Ground-based seismic and deformation monitoring approaches have proven
to be the most reliable and diagnostic in early detection and tracking
of volcanic unrest. In recent decades these two approaches have been
augmented by volcanic-gas, microgravity, geomagnetic, and remote-sensing
studies. Satellite-based methods are increasingly used for measuring
ground displacements and variations in thermal and volatile output at
volcanic centers. Experience worldwide shows that volcano surveillance
is best accomplished by on-site volcanic observatories or nearby
centralized facilities at which all of the monitoring data are
collected, processed and interpreted by experienced multi-disciplinary
scientific teams.

**Frequency of Measurement:** For frequently active volcanoes,
measurement should be continuous. For potentially active volcanoes
currently in repose, geophysical and geochemical baseline monitoring
data should be obtained and then followed by repeat measurements every
few years. However, after the recognition of possible departure from
baseline behaviour, the monitoring networks should be expanded and
measurements should be made on a more frequent, preferably continuous,
basis.

**Limitations of Data and Monitoring:** The paramount limitation in
detecting and tracking volcanic unrest is simply that no more than a
small percent of the world\'s volcanoes are now being monitored. An
overwhelming majority of the high-risk volcanoes are in developing
countries that lack sufficient economic and scientific resources to
conduct the necessary monitoring. Even in the richer nations, current
efforts to reduce government expenditures are compromising the
effectiveness of existing monitoring programs.

**Possible Thresholds:** With current knowledge and volcano-monitoring
techniques, it is not yet possible to determine a fixed threshold value
in the magnitude or duration of volcanic unrest, which, if exceeded,
inexorably leads to eruptive activity. However, at a few well-monitored
volcanoes, scientists are beginning to recognize patterns of build-up of
precursory geoindicators that characterize magma movement and/or
hydrothermal-pressurization effects at a given volcano.

**Key References:**

Ewert, J.J. & D.A.Swanson (eds) 1993. Monitoring volcanoes: techniques
and strategies used by the staff of the Cascades Volcano Observatory
1980-1990. U.S. Geological Survey Bulletin 1966.

McGuire, B., C.R.J.Kilburn & J.Murray (eds) 1995. Monitoring active
volcanoes: strategies, procedures and techniques. London: University
College London Press.

Scarpa, R. & R.I.Tilling 1996. Monitoring and mitigation of volcano
hazards. Berlin: Springer-Verlag.

**Related Environmental and Geological Issues:** Injections of volcanic
ash and gases high into the atmosphere during explosive eruptions can
have significant, and possibly global environmental effects. It is now
well documented that large explosive eruptions that form stratospheric
clouds of volcanic aerosols (e.g. Tambora, Indonesia, in 1815; El
Chichon, Mexico, in 1982; and Mount Pinatubo, Philippines, in 1991)
produce measurable effects on global climate, such as a hemispheric
cooling of up to 0.5C, that can persist for several years. In-flight
encounters between jet aircraft and volcanic ash have recently emerged
as a serious and growing volcanic hazard, as air traffic increases
worldwide.

**Overall Assessment:** Early recognition and systematic monitoring of
unrest in volcanic areas is essential. It can significantly mitigate
eruption-related hazards by improving understanding of volcanic
phenomena before, during and after eruptions, by refining long-term and
short-term eruption-forecasting capability, and by providing the
fundamental data for preparing hazard-zonation maps and for assessing
volcano hazards.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.

+---------+-------------------------------------------------+----------+
| !       | **GEOLOGIC RESOURCE MONITORING PARAMETERS**     | ![       |
| [](medi |                                                 | ](media/ |
| a/image | **Wind Erosion**                                | image3.p |
| 2.png){ |                                                 | ng){widt |
| width=" |                                                 | h="0.914 |
| 0.70902 |                                                 | 58333333 |
| 7777777 |                                                 | 33333in" |
| 7778in" |                                                 | height   |
| he      |                                                 | ="1.0541 |
| ight="0 |                                                 | 66666666 |
| .892361 |                                                 | 6667in"} |
| 1111111 |                                                 |          |
| 112in"} |                                                 |          |
+---------+-------------------------------------------------+----------+

**Brief Description:** The action of wind on exposed sediments and
friable rock formations causes erosion (abrasion) and entrainment of
sediment and soil particles \[see dust storm magnitude, duration and
frequency\]. Eolian action also forms and shapes sand dunes, yardangs
(streamlined bedrock hills) and other landforms. Subsurface deposits and
roots are commonly exposed by wind erosion. Wind can also reduce
vegetation cover in wadis and depressions, scattering the remains of
vegetation in interfluves. Stone pavements may result from the deflation
(removal) of fine material from the surface leaving a residue of coarse
particles. Blowouts (erosional troughs and depressions) in coastal dune
complexes \[see dune formation and reactivation\] are important
indicators of changes in wind erosion. The potential for deflation is
generally increased by shoreline erosion or washovers, vegetation
die-back due to soil nutrient deficiency or to animal activity, and by
human actions such as recreation and construction.

**Significance:** Changes in wind-shaped surface morphology and
vegetation cover that accompany desertification, drought, and
aridification are important gauges of environmental change in arid
lands. Wind erosion also affects large areas of croplands in arid and
semi-arid regions, removing topsoil, seeds and nutrients.

**Environment Where Applicable:** arid and semi-arid lands

**Types Of Monitoring Sites:** Dune fields, coastlines, desert surfaces

**Method Of Measurement**: Field observations, aided by airphotos and
field surveys. Changes in vegetation cover can be monitored using
historical records, sequential maps, air photos, satellite images, and
by ground survey techniques.

**Frequency Of Measurement:** Every 5-20 years

**Limitations Of Data And Monitoring:** The effect of wind erosion on
different rock types and landforms (with contrasted aerodynamic shapes)
varies, so that it is not easy to assess the degree of erosion of a
complex landscape.

**Key References:**

Abrahams, A.D, & A.J.Parsons 1994. Geomorphology of desert environments.
London: Chapman and Hall.

Cooke, R., A.Warren & A.Goudie 1993. Desert geomorphology. London: UCL
Press.

Lancaster, N. 1996. Geoindicators from desert landforms. In Berger, A.R.
& W.J.Iams (eds). Geoindicators: Assessing rapid environmental changes
in earth systems. :251-268.Rotterdam: A.A. Balkema.

**Related Environmental And Geological Issues:** Degradation of
agricultural land, desertification.

**Overall Assessment:** Wind erosion is a valuable indicator of
environmental change in arid and semi-arid regions.

**Source**: This summary of monitoring parameters has been adapted from
the Geoindicator Checklist developed by the International Union of
Geological Sciences through its Commission on Geological Sciences for
Environmental Planning. Geoindicators include 27 earth system processes
and phenomena that are liable to change in less than a century in
magnitude, direction, or rate to an extent that may be significant for
environmental sustainability and ecological health. Geoindicators were
developed as tools to assist in integrated assessments of natural
environments and ecosystems, as well as for state-of-the-environment
reporting. Some general references useful for many geoindicators are
listed here:

Berger, A.R. & W.J.Iams (eds.) 1996. Geoindicators: assessing rapid
environmental change in earth systems. Rotterdam: Balkema. The
scientific and policy background to geoindicators, including the first
formal publication of the geoindicator checklist.

Goudie, A. 1990. Geomorphological techniques. Second Edition. London:
Allen & Unwin. A comprehensive review of techniques that have been
employed in studies of drainage basins, rivers, hillslopes, glaciers and
other landforms.

Gregory, K.J. & D.E.Walling (eds) 1987. Human activity and environmental
processes. New York: John Wiley. Precipitation; hydrological, coastal
and ocean processes; lacustrine systems; slopes and weathering; river
channels; permafrost; land subsidence; soil profiles, erosion and
conservation; impacts on vegetation and animals; desertification.

Nuhfer, E.B., R.J.Proctor & P.H.Moser 1993. The citizens\' guide to
geologic hazards. American Institute for Professional Geologists (7828
Vance Drive, Ste 103, Arvada CO 80003, USA). A very useful summary of a
wide range of natural hazards.