**Course Title:** **Floodplain Management**

**Module 2:** Stream Systems on Dynamic Earth

**Session 4**: Meteorological Processes -- The Production of Water on
Land

**Author**: Dr. Donald R. Reichmuth, P.E., President, Geomax, P.C.,
Spokane, WA

(E-mail -- <Geomax@comcast.net>)

**Time 75 minutes**

# 

# Objectives: (PP 1 -- 2, Title and Objectives)

At the end of this session, the students will be able to:

4.1 Show how temperature and pressure gradients affect North American
atmospheric conditions.

4.2 Show how water sources are generated and distributed on earth.

4.3 Explain the concepts of a **catchment area** and a **river basin**
and show how they are related.

4.4 Explain how to find and use published resources concerning drainage
basins; climate and stream flow history and predicted behavior.

4.5 Examine how drought and other meteorological conditions besides
flooding can cause major disruptions of streams and river basins.

4.6 Illustrate how elevation, location, and surface cover affect weather
patterns and runoff in drainage basins.

4.7 Discuss metrological processes within the context case study
floodplains.

**Scope:**

During this session, the instructor first explains the atmosphere's
driving forces and the hydrologic cycle. Then watershed parameters are
defined; critical watershed data illustrated, and local characteristics
effecting stream flow in the river basins shown.

**Readings:**

***Student:***

[General Overview]{.underline}

Pidwirny, M., 2004. *Fundamentals of Physical Geography*, Chapter 7 --
Introduction to the Atmosphere. & Chapter 8 -- Introduction to the
Hydrosphere.

On line at: http://www.physicalgeography.net/home.html

***Instructor Reading:***

Flannery, T., 2001, *The Eternal Frontier*, Grove Press, 404 pgs.

Groisman, P.Y., Knight, R.W., & Karl, T.R., 2001, *Heavy Precipitation
and High Streamflow in the Contiguous United States: Trends in the
20^th^ Century*, Bulletin of the American Meteorological Society,
February 2001.

Easterling, J.L., et.al., 2000, *Observed Variability and Trends in
Extreme Climate Events: A Brief Review*, Bulletin of the American
Meteorological Society, 81, March 2000, Pg 417-425.

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**General Requirements:**

The students should start to apply the concepts learned in this session
to their individual Case Studies. During class, the instructor should
spend some time engaging the students in a discussion of local
meteorological conditions that impact the local streams.

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**Objective 4.1** **Show how temperature and pressure gradients affect
North American atmospheric conditions.**

**Requirements:**

The information in this section is presented as a lecture using the
Power Point slides.

**Remarks:**

The water in all streams is intimately tied to the world's oceans. The
sun provides the energy to move water from the oceans to continental
areas where it falls as precipitation. It is important in this session
to develop a comprehensive view of water's availability, movement, and
physical properties.

I.  **North American temperature varies considerably. (PP 3, North
    American Temperature Data)**

    A.  The Mid-Continent area has the greatest range.

        1.  Winters are cooled by air coming south from Canada. **(PP 4,
            Winter Temperature Data)**

        2.  Summers are heated by ground absorption of the sun's
            radiation.

II. **The sun's heat primarily drives** **atmospheric circulation**.

    A.  Water evaporates from the ocean.

    B.  Convection carries water to land areas.

    C.  Pressure systems distribute moisture-laden clouds.

        1.  Weather systems in North America are controlled by ground
            temperature and topography.

            a.  The Mid-continent area has hot summers and cold winters

            b.  Western mountains tend to act as **barriers**.

            c.  The system has a **Monsoon Pattern**. **(PP 5, North
                American Air Flow) (PP 6, Monsoon Air Flow (Summer) PP
                7, Monsoon Air Flow (Winter)**

**Supplemental Considerations:**

The instructor should identify the typical, local atmospheric
circulation pattern and provide some examples of how nearby streams are
affected.

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**Objective 4.2 Show how water sources are generated and distributed on
earth.**

**Requirements:**

The information in this section is presented as a lecture using **Power
Point** slides.

**Remarks:**

I.  Water on earth comes from outer space, volcanoes, and rock
    disintegration.

II. The total volume of water on earth is 309,000 Units. (PP 8, Earth's
    Water)

    A.  For this Course, a Unit is defined as 4475 Cubic Km or 1070
        Cubic Miles.

        1.  This arbitrary [Unit is]{.underline} chosen for this course
            to simplify comparison between various types and locations
            of water sources.

            a.  The present yearly evaporation from all oceans is 100
                Units.

            b.  The present volume of all oceans is 300,000 Units.

III. Water is found in many forms and locations on earth. (PP 9, Water
     Distribution)

     A.  The oceans and sea ice contain **300,000 Units (97%)** of all
         water on earth at the present time. This water is salty and
         unfit for most on-land uses.

     B.  **Glaciers and ice caps** now contain **6000 Units (2%)** of
         water. This water is fresh . (2004 estimate).

         1.  The relative abundance of water contained in oceans and ice
             varies considerably over time (i.e. "ice ages
             come-and-go").

             a.  During the last ice age, glaciers contained **18,000
                 Units** of water.

             b.  This water was removed from the oceans, which caused
                 the ocean levels to **drop about 140 meters**.

     C.  **Water remaining** at all other locations amounts to only
         about **3000 Units (1%)** of the total at present.

         1.  **Groundwater** accounts for about **2950 Units** of this
             total.

             a.  About **150 Units** of this groundwater can move into
                 and out of streams. This portion is active and is
                 usually fresh**.**

             b.  About **1200 Units** of this groundwater is located in
                 **aquifers** that were filled by precipitation during
                 earlier, wetter periods (i.e. during glacial periods,
                 for example). This portion is **inactive (meteoric);**
                 usually is fresh and can be "mined" by pumping from
                 wells.

             c.  The remaining groundwater (**1600 Units)** was trapped
                 in rock formations during original deposition. This
                 portion is old formation **(connate)** water**;**
                 usually is salty and often brought to the surface as
                 **brine** during oil well development and extraction.

         2.  Inland lakes and seas now make up about **50 Units** of
             this total.

             a.  Salty lakes (i.e. Great Salt Lake) make up about half.

             b.  Fresh water lakes (i.e. Lake Superior) make up the
                 other half.

         3.  The remaining water **(about 3.5 Units)** is located in the
             atmosphere and in streams.

             a.  These sources are constantly being transferred from one
                 location to another by heat energy and gravity.

             b.  The total water stored in the **atmosphere** is about
                 **3 Units**.

             c.  The total water stored in **streams is** about **0.28
                 Units or less than 0.0001%** of the total earth's
                 water.

             d.  Water in these latter two sources is extremely
                 important in maintaining life of earth; but they make
                 up an extremely small percentage of the total water
                 present on the planet.

IV. **The movement of water on earth is called the Hydrologic Cycle. (PP
    10, Hydrologic Cycle) (PP 11, Simplified Hydrologic Cycle) (PP 12,
    Detailed Hydrologic Cycle)**

    A.  The sun provides the primary energy source for evaporating
        water.

        1.  **100 Units per year** are taken into the atmosphere from
            the oceans.

        2.  **16 Units per year** are taken into the atmosphere from
            land areas.

    B.  **Convection** is then primarily responsible for moving **10
        Units per year** of condensed ocean water to land areas. The
        rest **(90 Units per year)** falls back into the oceans.

    C.  **26 Units per year** falls on land from clouds as rain or snow.

    D.  When precipitation falls on land, it is either absorbed into the
        ground or runs off in surface streams.

**Supplemental Considerations:**

Presenting local examples of evaporation and precipitation rates should
spark student interest.

**Objective 4.3 Explain the concepts of a catchment area and a river
basin and show how they are related.**

**Requirements:**

The information in this section is presented as a lecture using **Power
Point** slides.

**Remarks:**

The instructor must make it clear that a SURFACE catchment area and a
GROUNDWATER catchment area often include different topographic areas. A
SURFACE catchment area always falls within one river basin but a
GROUNDWATER catchment area **may** include parts of multiple river
basins.

I.  **Precipitation falling on the land surface becomes runoff and it
    can take different paths. (PP 13, Runoff Defined)**

    A.  Water can be taken back into the atmosphere by **evaporation,
        sublimation, or transpiration.**

    B.  Water can enter streams as surface flow.

        1.  Surface flow is controlled by **surface topography**.

        2.  The s**urface catchment area** is that area of a river basin
            upstream from a given point on a stream where **surface
            runoff** is determined. **(PP 14, Catchment Defined)**

    C.  Water can soak into the ground and become **groundwater**.

        1.  Groundwater flow is controlled by **subsurface structure.**

        2.  The flow may move in directions different from surface flow.

        3.  The **groundwater catchment area** is all areas that
            contribute recharge to the subsurface aquifer.

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I.  **Topographic and geologic maps are used to define river basin and
    catchment areas.**

    A.  Topographic maps define: **(PP 15, River Basin Example) (PP16,
        Basin Topographic Map)**

        1.  Surface flow paths.

        2.  Cultural features that affect runoff and infiltration.

        3.  Surface water storage areas.

        4.  Computer-generated maps are now available that show
            3-dimensional landforms. **(PP 17, Block Diagram)**

    B.  Geologic maps define:

        1.  Subsurface flow paths.

        2.  Subsurface water storage zones.

        3.  Subsurface permeability and porosity.

        4.  The location and shape of the groundwater catchment area.

**Supplemental Considerations:**

It would be preferable to use diagrams for a local river basin in the
PowerPoint presentation. This substitution would allow the students to
use familiar names and locations to better visualize the elements of a
river basin.

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**Objective 4.4 Explain how to find and use published resources
concerning drainage basins; climate and stream flow history and
predicted behavior.**

**Requirements:**

The information in this section is presented as a lecture using Point
slides.

**Remarks:**

I.  The Federal government collects and distributes large amounts of
    topographic and hydrologic data that can be used in analyzing past,
    present, and future conditions concerning climate, river basin, and
    stream conditions.

    A.  The U.S. Geologic Survey (USGS) provides the following data:

        1.  Topographic maps (7 ½ minute quads) at scale 1:24000

        2.  Geologic (both surface and subsurface) maps of many areas.

        3.  Hydrologic and river basin maps.

        4.  Hydrologic data (Stream gages)

    B.  The National Oceanic & Atmospheric Administration (NOAA)

        1.  National Weather Service (NWS)

            a.  Web homepage --
                [**http://www.nws.noaa.gov**](http://www.nws.noaa.gov/)

            b.  The NWS operates the Climate Prediction Center that
                provides both short and long term weather forecasts.
                These forecasts include predictions and alerts
                concerning stream flood stages. (PP 18, Moisture
                Forecast)

            c.  The US is organized into Regional Centers that provide
                river forecasts. See
                [**http://www.nws.noaa.gov/er/nerfc**](http://www.nws.noaa.gov/er/nerfc)
                for the locations of specific locations. (PP 19, River
                Forecast Centers)

            d.  The NWS provides a periodic, national Hazards Assessment
                Briefing. (PP 20, Hazards Assessment Briefing) See
                [**http://www.cpc.ncp.noaa.gov/products/predictions/threats**](http://www.cpc.ncp.noaa.gov/products/predictions/threats)

    C.  The National Resources Conservation Service (NRCS) (PP 21,
        Precipitation Data)

        1.  Western Regional Climate Center

            a.  Web homepage --
                [**http://wrcc.dri.edu/index.html**](http://wrcc.dri.edu/index.html)

            b.  Snow survey data from SNOTEL sites. (PP 21, NRCS Snow
                Water Content) See
                [**http://mt.nrcs.usda.gov/snow/data/current.html**](http://mt.nrcs.usda.gov/snow/data/current.html)

            c.  Basin precipitation data (PP 23, River Basin
                Precipitation Data) See
                [**wrcc@dri.edu**](mailto:wrcc@dri.edu)

        2.  National Climate Data Center

            a.  General climate information for entire country. See
                [**http://wrcc.dri.edu/climmaps**](http://wrcc.dri.edu/climmaps)

    D.  National Weather Service (NWS)

        1.  General Weather Forecasts.

        2.  River Forecast Center (RFC)

            a.  Issues Flood Threat predictions (PP 24, Flood-threat
                Example).

            b.  Issues Flood Risk predictions (PP 25, Flood Risk
                Example).

        3.  Advanced Hydrologic Prediction Service (PP 26, Flood Warning
            Example). See
            [**http://www.noaa.gov/ahps/rhc.html**](http://www.noaa.gov/ahps/rhc.html)

    E.  Federal Emergency Management Agency (FEMA)

        1.  Flood (FIRM) Maps

        2.  Community flood studies.

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G.  USACOE

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1.  Basin specific studies

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I.  Numerous state, county and city agencies collect resource data for
    their jurisdictional areas.

**Supplemental Considerations:**

The instructor should identify and explain local sources of resource
data that the students could use in their case studies.

Objective 4.5 Examine how drought and other meteorological conditions
besides flooding can cause major disruptions of streams and River
Basins.

I.  There are numerous ways a floodplain can be impacted besides being
    flooded.

    A.  Drought can radically change riparian vegetation making channels
        more unstable.

    B.  Drought can make river basins more susceptible to fire.

    C.  Chemical pollutants can significantly alter streams and
        floodplains.

        1.  Chemicals (from pipeline ruptures, for example) can be
            mobilized during storm events and carried into streams where
            they can wipe out in-steam habitat and organisms.

        2.  Agricultural chemicals can leach or be carried by wind into
            water systems causing over fertilization and/or poisoning.

        3.  Airborne pollutants (sulfur dioxide from power plants for
            instance) can kill vegetation and change the surface water
            pH.

II. There are a number of ways to determine and characterize drought
    susceptibly.

    A.  The Palmer Drought Severity Index (PDSI) is a measure of
        moisture conditions within regions. (PP 27, Palmer Drought
        Severity Index)

    B.  Historic data has been recovered using Dendrochronology (the
        study of tree rings). (PP 28, Dendrochronology)

        1.  Laboratory of Tree-Ring Research at the University of
            Arizona is one major dendrochronology research center

        2.  Over 2000 years of climate conditions have been determined
            using this method.

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III. A number of groups in the U.S. study drought.

     A.  National Drought Mitigation Center (NDMC) (PP 29, Drought
         Information Center)

     B.  Web Homepage -- [**http://www.ndmc@drought.unl.edu**]()

     C.  Provides information on drought conditions and risk

     D.  U.S. Drought Monitor. (PP 30, Drought Conditions) See
         [**http://www.drought.unl.edu/dm/monitor.html**](http://www.drought.unl.edu/dm/monitor.html)

     E.  Drought Prediction (PP 31, Drought Prediction). See
         [**http://www.ncep.noaa.gov/products/expert_assessment/season_drought.gif**](http://www.ncep.noaa.gov/products/expert_assessment/season_drought.gif)

     F.  NOAA Drought Information Center. See
         [**http://www.drought.noaa.gov**](http://www.drought.noaa.gov/)

     G.  National Interagency Fire Center. See
         [**http://www.nifc.gov**](http://www.nifc.gov/)

**Objective 4.6** **Illustrate how elevation, location and surface cover
affect weather patterns and runoff in drainage basins.**

**Requirements:**

The information in this section is presented as a lecture using Power
Point slides.

**Remarks:**

I.  **Local Microclimates can have significant impact on local climate.
    (PP 32 Local Microclimates)**

    A.  **Orographic** conditions (**mountain barriers** interfering
        with wind patterns) often control precipitation patterns. **(PP
        33, Topographic Influence)**

        1.  Moisture laden clouds often drop moisture as they rise to
            pass over mountain barriers. **Rain Forest** conditions can
            develop.

        2.  Airflow down mountain slopes causes the air to heat and draw
            moisture from the terrain. **Rain shadow** conditions can
            develop.

    B.  **Smoke Stack Emissions** can cause the precipitation to become
        **acidic**. **(PP 34, Effect of Smoke Stack Emissions)**

        1.  Mid-west power plants often burn high sulfur coal.

        2.  Sulfuric acid forms in the clouds.

        3.  **Acid rain** often falls in the Northeastern USA and
            Southeastern Canada.

    C.  Urban areas often produce sufficient heat to change local
        climate. This heating creates local **"Heat Islands." (PP 35,
        Effect of Urban Heat Islands)**

    D.  Large lakes often create high precipitation areas downwind**.
        "Lake Effect"** snowfall is common. **(PP 36, Lake Effect on
        Snowfall)**

        1.  Areas east of the Great Lakes are affected.

        2.  Mountains east of the Great Salt Lake in Utah are affected.

II. **Runoff is not uniform in the U.S. (PP 37 Average Runoff
    Patterns)**

    A.  Except in the Pacific Northwest, the average runoff east of the
        Mississippi River is significantly greater than to the west.

    B.  The difference (as a percent of the average) between peak flows
        (flood stage) and low flow (base flow) is greater west of the
        Mississippi River than to the east.

        1.  The term "flashy drainage" is often used to describe this
            type of river basin.

        2.  Loss of surface vegetation significantly increases "flashy
            behavior".

    C.  Mountains always produce more runoff than nearby lower areas.

        1.  This difference has led to widespread use of irrigation
            systems to the lower agricultural areas that are naturally
            too dry to support crops.

        2.  Water withdrawals from streams to support agriculture often
            dewater streams.

**Supplemental Considerations:**

The instructor should identify the local site-specific conditions that
modify the local climate and precipitation pattern.

**Objective 6.7 Discuss Metrological processes within the context case
study floodplains.**

**Remarks:**

A.  Students will continue to work on Task 1. The instructor should
    spend some class time answering questions concerning problems that
    the Student Groups might have in researching their Case Studies.
    Additionally, the instructor should emphasize that the Handouts from
    Session 2 are to be used as a guide in preparing their presentations

**References:**

> Sverdrup, K.A., Duxbury, A.C., Duxbury, A.B., 2003. *An Introduction
> to the World's Oceans,* 7^th^ Edition, McGraw-Hill
>
> Chapter 1 -- The Water Planet \-\-\-- This chapter is an excellent
> introduction to mapping, water distribution, geologic time, and the
> hydrologic cycle.
>
> Chapter. 2 -- Plate Tectonics \-- This chapter reviews the material
> covered in\
> Session 2.
>
> Chapter. 4 -- The Physical Properties of Water \-\-\--This chapter
> defines most of the basic physical properties of water that control
> behavior.
>
> Chapter. 6 -- The Structure and Motion of the Atmosphere \-\-\-- This
> chapter describes the basic atmospheric makeup, driving forces and
> flow patterns.