bluuebunny/crossref_metadata_2025 huggingface dataset:
Sediment Transport
Authors: Mikos Matjaz
Published: April 2005

Sediment transport is a natural process of transporting solid particles called sediments from erosion sources to deposition or sedimentation areas. This process has been shaping landscapes throughout geological time. Sediments, sedimentary rocks, and the process by which they were formed are scientifically studied by sedimentology.

One important source of sediments is soil erosion. Geologic soil erosion occurs as surface removal of farm, forest, and other erodible soils in the form of sheet erosion, interrill and rill erosion, gully erosion or deflation, mainly caused by impacts of raindrops (splash erosion, rain erosion) and overland flow on bare soils or land without dense vegetative cover to protect soils. It may be checked on farm soils by such farm management practices as contour plowing, crop rotation, and mulching. Accelerated erosion is the speeding up of erosive processes, such as deforestation, overgrazing, and construction, either directly or indirectly, by the intervention of humans. Its most obvious effects can be seen in the alteration of a river's regime by improper land use or by human intervention into the catchment area. Other important sediment sources are deposits of mass wasting phenomena, driven by gravity, such as rockfalls, rockslides, landslides, debris flows, and mudflows, exposed to fluvial processes of erosion, transportation, and sedimentation. The subjects of these processes are fluvial sediments—solid particles and particles of rock material that have been transported from their sources and deposited elsewhere by flowing water.
Curious Uses of Agricultural Water in the World
Authors: Mollard Eric P.
Published: April 2005

Wetlands show two contradictory characteristics: they discourage and they attract. They are inhospitable because of the fear of marsh fevers, wizards, and legendary animals. More prosaically, great land fertility and moisture are beneficial at the cost of hard labor, not in the direction of general draining, but in that of the work for horticulture. The promise of such lands that have high productivity and are healthiers when water is under control, could overcome the fears, real or imaginary, of the wilderness.
J
acob's Well
Authors: Holst Arthur M.
Published: April 2005

Jacob's well was dug two miles southeast of the ancient city of Schechem, an area that is currently recognized as the city of Nablus in Israel. The generally accepted history of this well begins with Jacob, the original owner of the well and one of the Hebrew patriarchs.
A Concise Glimpse of Water in the History of Photography
Authors: Irland Basia
Published: April 2005

Water is universal and indispensable to life. Therefore, it has always been a central metaphor, both sprightly and exacting, for artists. In this brief article, we examine how a few photographers have looked to water for inspiration and also used it as the very substance of their work. There have, of course, been hundreds of photographers who have tested water as their subject matter or used it in their work in various ways at some stage of their career; some of the more notable and interesting are presented here. A few examples have been chosen, beginning with the earliest photographers of the nineteenth century.
Canals in the
M
ekong
D
elta: A Historical Overview from 200
C
.
E
. to the Present
Authors: Biggs David
Published: April 2005

The Mekong Delta is one of the most productive agricultural regions in the world. It supports more than 20 million people living in a dense network of canals and creeks that today irrigate more than 2 million hectares of rice paddy. This landscape of dense settlement and intensive irrigated agriculture is relatively recent, although the earliest canal projects date to “Fu Nan” or Oc Eo culture circa 200
C.E.
Today's water regime is not so much a single water system as it is a landscape built of multiple layers of canals in various stages of development and degradation. Some waterways continue to serve as primary transportation and irrigation works: others lie abandoned, their traces sometimes only visible through analysis of aerial photography or historical reports. This overview describes these historical layers of canalization and the context for some of the major projects in each period.
J
aubert
de
P
assa: The First World History of Irrigation in 1846
Authors: Mollard Eric P.
Published: April 2005

The first world history of irrigation appeared in 1856, and it has remained the only one to the present. The four volumes of the “Recherches sur les arrosages chez les peuples anciens” (Research on Watering among Ancients) describe hydraulic enterprizes from the most modest to the most monumental, and provide the political and social history of people who mobilized and organized themselves for this purpose.
Water and the History of Man
Authors: Azadpour‐Keeley Ann , Keeley Jack W.
Published: April 2005

In the days of Abraham, following family feuds and other conflicts, the victor often stopped wells by filling them with earth and stones. It was the equivalent of burning the village. Wells of water were so important that their owners gave them names, and communities which took root in the area assumed the names of the wells. In John 4:6, Jesus meets a woman from Samaria at Jacob's well and later reveals that He is the Messiah. The Christian Bible is replete with references to the importance of water to the fabric of life. It speaks of irrigation, of aqueducts, its creation, its purification, and even of it being turned into wine.
Water in History
Authors: Petts Geoff
Published: April 2005

The story of water in history is about human ambition to achieve food security, economic growth, and political power. It is both a social and a technological history. The history of civilization is about social organization and coordination, and for six millennia, successful water resource management was the basis of civilizations. Early cultures were built on the food surpluses produced by managing the floodwaters of large rivers for irrigation. In humid areas dominated by rain‐fed agriculture, water was influential in other ways by enabling trade along inland waterways. Water also powered mills that fueled industrial and economic growth. But the successful use of riparian and floodplain sites was frequently interrupted by tragedies caused by flood and drought. The notorious Huang He was popularly known as ‘China's Sorrow’ because of its devastating floods and dramatic changes in its course, but it is also prone to severe droughts. In recent history, major floods in 1855 and 1938 took millions of lives and in destroying crops, brought widespread famine and disease. In the great drought of 1877–79, 13 million people died of starvation. Similarly, early Sumerian and Babylonian civilizations had to survive flood disasters. The Biblical famine described in Genesis (47: 13–21) may relate to a period of persistent drought when the Nile flood failed. In more recent times, the great Mississippi flood of 1927 was a disaster for millions of people, and it also changed the course of the American nation.
BenFranklin'sGulfStream Weather and Swim Fins
Authors: Marks William E.
Published: April 2005

The initial concept of creating Franklin's famous chart of the Gulf Stream was prompted in 1768 when Franklin was in London serving as Deputy Postmaster General for North America (Van Doren, 1938). While in London, Franklin received complaints from America as to how westbound mail packets [English ships] took up to two weeks longer than American merchant ships (5)Am. Philos. Soc.lxxvi (5). (1936). At about the same time, the English postal authorities had written to Franklin asking similar questions (Cohn, 1998; Richardson, 1980). These inquiries from Americans and the English about the speed of ships crossing the Atlantic prompted Franklin to do some research.

While researching the answers to these complaints in 1768, Franklin made inquiries of Timothy Folger, who happened to be in London at the time. Folger informed Franklin that based on experience, Nantucket whalers had developed a working knowledge of the Gulf Stream between Europe and America. This knowledge came from the whalers following the migration patterns of whales, which were consistently found north or south beyond the edges of the Gulf Stream, but never inside the Gulf Stream. Whaling captains from Nantucket and Martha's Vineyard knew that whales could be found feeding along the Gulf Streams plankton‐rich boundaries. They also had learned that sailing back to New England whaling ports could be achieved in less time by staying north of the Gulf Stream and thereby avoiding its current.
Wetlands Policy in theUnitedStates: From Drainage to Restoration
Authors: Gerlak Andrea K.
Published: April 2005

Historically, swamps have been regarded as wastelands, evoking reactions of “disgust at their sight and smell, fear of malaria and yellow fever, and unease about rich resources running to waste within them.” By the beginning of the twentieth century, perceptions began to change. Sportsmen and hunters called attention to declining number of waterfowl and initial federal efforts regarding wetlands focused almost exclusively on waterfowl habitat. In 1903, President Theodore Roosevelt established the first National Wildlife Refuge by executive order to protect endangered species on Pelican Island, Florida. With the Migratory Bird Hunting Stamp Act of 1934, Congress established a special fund to finance wetland acquisitions for duck habitat.
Economic Value of Water: Estimation
Authors: Ramírez‐Vallejo Jorge
Published: April 2005

The global awareness of the vital role water plays in sustainable national development is increasing. Water is vital for sustaining life on the earth. It is crucial for economic and social development, including energy production, agriculture, and domestic and industrial water supplies. Therefore, each unit of water should be used efficiently, equitably, and soundly. The economic value that water generates should be given due attention, when apportioning scarce water resources among competing uses.

Water is often regarded as a naturally occurring, freely available commodity. However, its supply, especially in an unpolluted state, is often limited compared to the demands placed upon it. Hence, water is both a constraint on and an essential input of economic activity, and decisions are required to allocate it among competing uses.
Water Supply Planning—Federal
Authors: Feldman David L.
Published: April 2005

The U.S. government has been engaged in water supply planning for domestic, agricultural, commercial, and industrial needs from its inception. Planning was initially undertaken for inland navigation and flood control. Later, primacy was given to irrigation, municipal needs, and hydroelectricity. The Army Corps of Engineers, the largest and most important federal water supply planning entity, was initially given responsibility for all these efforts. In 1902, the Bureau of Reclamation (BOR) was established and given principal responsibility for water supply projects in the West.
Water Transfers
Authors: Feldman David L.
Published: April 2005

Water transfers are the diversion, reallocation, or appropriation of surface or groundwater from one watershed, drainage basin, or aquifer to another. All transfers entail water exchange between catchments. They may also move water from one
political jurisdiction
to another, exacerbating their impacts and complicating efforts to resolve stakeholder conflicts that they generate. In addition, transfers may be endeavored through various
means
including pipelines, tunnels, aqueducts, pumping facilities, or even seaborne tankers—an idea contemplated under proposals to transfer water from the Great Lakes to the Middle East.
Quantitative Groundwater Law
Authors: Lawson Marshall
Published: April 2005

From ancient times, the law looked upon surface water and groundwater as separate resources, requiring separate rules for ownership and use. Whereas surface water was considered a public good to be shared among competing users, groundwater was equated with private property to be appropriated by the landowner at will.

The separate classification and treatment of groundwater can be attributed, in part, to a primitive understanding of hydrogeology; a mathematical description of groundwater storage and movement was not formulated until the midnineteenth century and not widely disseminated until the late twentieth century. Without an understanding of aquifer characteristics, legal authorities lacked a basis for developing sophisticated groundwater allocation rules. The occurrence and nature of groundwater was, to them, too “… uncertain …[to] subject it to the regulations of law…”.
Representing Geopolitics of (Hydro) Borders in
S
outh
A
sia
Authors: Saroch Eva
Published: April 2005

In the tradition of political geography, the concept of boundary/border has been of major importance where researchers have understood it mainly as an empirical manifestation of political processes and particularly of the sovereignty of the state. But borders not only represent a ‘fixed line’ in space or time, rather, they need to be understood as being produced and reproduced in the
socio‐spatial consciousness
of society a (broader form of consciousness that reflects the ideological and hegemonic structures). Therefore, it is argued here that boundaries, apart from being located on terra‐firma as a physical line, also exist metaphorically, symbolically in many ways as a manifestation of socio‐spatial consciousness and as ‘plays of power’ that generate and exert various codes, rules and procedures of ‘distinction’ in the process of Othering such as us/them, sacred/profane, inclusive/exclusive, to impose specific understanding through the construction of knowledge in sociocultural practices and discourses in politics, administration, economics, or the organization of ethnic relations on various scales.
Legal Protection for In‐Stream Flow
Authors: Kassen Melinda R.
Published: April 2005

In the United States, states, rather than the federal government, have primary authority over water allocation. Those states west of the 100th meridian are, for the most part, arid or semiarid. Since early in their settlement, they have found a need to reconcile disputes between water users; each of these states follows the doctrine of prior appropriation to allocate water among competing users. Each state's system is unique, but their systems share many features. Most importantly, these systems define the value of water in terms of its use, and until late in the twentieth century, this meant use out of the stream. The prior appropriation system did not recognize any value for leaving water in a stream. Because the prior appropriation system functions as a seniority system, where the earliest user of a river retains always the first right of use, the system has created a challenge today for states and others seeking to protect remaining in‐stream values, where water is “unused” except in sustaining the environment or by recreationists in a non‐consumptive manner.
The National Pollution Discharge Elimination System
Authors: von Oppenfeld Rolf R.
Published: April 2005

All facilities that discharge pollutants from a point source into waters of the United States must obtain a National Pollution Discharge Elimination System (NPDES) permit from the EPA or an authorized state [42 U.S.C. §§ 1311(a), 1342; 40 C.F.R. § 122.1(b)]. Permits typically allow the permittee to discharge specified pollutants from designated outfalls. See the NPDES program homepage at
http://www.epa.gov/npdes/
. The NPDES program generally imposes technology‐based standards and water‐quality‐based effluent limits on point source discharges of pollutants to surface waters, although less stringent requirements presently apply to stormwater runoff discharges.

Currently, 46 states and territories are authorized (have primacy) under Section §r402(b) of the CWA to administer the NPDES program. The EPA regions are the lead permitting authority in the other states and territories. State NPDES programs must use federal standards as a baseline; however, states may impose stricter requirements.
Biosorption of Toxic Metals
Authors: Loukidou M. X. , Zouboulis A. I.
Published: April 2005

Generally, biosorption is a treatment process that uses inexpensive biomass, usually by‐product, to sequester toxic metals from contaminated effluents. Biosorbents can be prepared from natural abundant biomass sources, such as seaweeds, or from waste biomass of algae, fungi or bacteria.

Generally, biosorption is a treatment process that uses inexpensive biomass, usually by‐product, to sequester toxic metals from contaminated effluents. Biosorbents can be prepared from natural abundant biomass sources, such as seaweeds, or from waste biomass of algae, fungi or bacteria.

The unique capabilities of certain types of biomass to concentrate and immobilize particularly heavy metal can also offer some degree of selectivity. This property depends on the following parameters:

the specific type of biomass,

the mixing conditions of the suspension,

the type of biomass preparation, and

the specific physicochemical conditions.

Broad‐range biosorbents can collect most of the heavy metals from an aqueous solution (wastewater), presenting rather a smaller degree of selectivity among them. A specific metal can be separated either during sorption uptake, by manipulating the properties of a biosorbent, or upon desorption during the regeneration cycle of the biosorbent.
Field Sampling and Monitoring of Contaminants
Authors: Downs Timothy J.
Published: April 2005

Field sampling and monitoring of water/wastewater contaminants are strategically important for more sustainable integrated water resources management (IWRM). One of the vital first steps in IWRM is the collection of an inventory that characterizes existing watershed conditions. Relevant features include geographic and environmental aspects (e.g., land use, topography, wetlands), infrastructure (e.g., supply, sewerage and drainage), municipal data (e.g., numbers of people, growth rate, regulations, by laws), pollution sources/discharges (point and nonpoint sources, e.g., landfills, underground storage tanks), and the characteristics of receiving surface waters and groundwaters (indicators of flow rates and physical, chemical, biological, and microbiological quality).

Water quality problems that require characterization through sampling and monitoring are a combination of the effects of human use and degradation of water in domestic, industrial, commercial, and agricultural activities (and its discharge as wastewater), and the impact of human activities that change land use/land cover on the water quality of runoff.
Overview of Analytical Methods of Water Analyses With Specific Reference to
EPA
Methods for Priority Pollutant Analysis
Authors: Tella Ralph J.
Published: April 2005

This article is an overview of the analytical chemistry behind the analyses of common environmental contaminants. Specific reference is made to the U.S. Environmental Protection Agency (EPA) “priority pollutants.” The list of priority pollutants was first published in the Federal Register in 1980 as the list of toxic pollutants for which categorically defined industries were required to analyze their effluent streams to obtain wastewater discharge permits under the National Pollution Discharge Elimination System (NPDES).
pH
Authors: Dziewatkoski Michael P.
Published: April 2005

Some chemical compounds, when dissolved in water, dissociate to yield hydrogen ions (H+, e.g., protons) and are called acids. Other compounds called bases yield hydroxide ions (OH−), when dissolved in water. The relative strength of an acid or base is related to the degree of dissociation that the compound undergoes. A strong acid is one that dissociates completely to yield a relatively large number of hydrogen ions, whereas the strong base is a compound that yields a relatively large number of hydroxide ions.
The Economics of Water Quality
Authors: Keplinger Keith O.
Published: April 2005

The role of economics in water quality decision‐making is a topic receiving increasing attention today. A number of factors have spurred this interest. On the policy front, the total maximum daily load program has emerged as a premier water quality program in the United States, engendering fresh opportunities for economic analysis, because the means of attaining ambient targets are not prescribed. The increased relevance of economic analysis in the policy arena has been accompanied by a blossoming of the discipline of environmental economics and greater public and governmental acceptance of pursuing cost‐effective and market‐based solutions to environmental problems.

The theory of environmental economics has been extensively developed, but the utility and form of policy instruments are highly influenced by the institutional landscape. Consequently, this report begins with a brief assessment of water quality policy in the United States, focusing on the landmark legislation that constitutes the lion's share of current water quality policy, the 1972 Clean Water Act (CWA). Next, the meaning of costs and benefits in a water quality context are discussed, and the merits of two commonly used economic instruments in water quality assessments are explored: cost–benefit analysis and cost‐effectiveness analysis. Finally, equity issues and the economic implications of water quality policy alternatives are discussed, with particular emphasis on the historical development and potential for incentive‐based mechanisms.
Toxicity Identification Evaluation
Authors: Markle Philip J.
Published: April 2005

Identification of what is “toxic” in aquatic toxicity tests is most often determined quantitatively through the regulatory process as permit limits or objectives and no definitive standards have been defined or are universally used. Although no universal definitions exist, several measures of toxicity are more commonly employed and seem to have achieved greater acceptance. These include the use of the “no observed effect concentration” (NOEC) or “no observed effect level” (NOEL). The NOEC and NOEL use hypothesis testing to identify statistically significant differences relative to a nontoxic control. The NOEC or NOEL is defined as the highest concentration not significantly different from the control. Another commonly used analysis involves various point estimation techniques. These quantitative analyses use dose–response data to estimate “safe” or “nontoxic” concentrations or effects using metrics such as the LC
50
(lethal concentration causing a 50% effect) or EC/IC
25
(effective or inhibition concentration causing a 25% effect). Due to the large amount of toxicity testing required in the TIE process, reductions in testing replication and exposure volume and duration are often made to save on sample and staffing resources.
Trace Element Contamination in Groundwater of District
H
ardwar,
U
ttaranchal,
I
ndia
Authors: Jain C. K.
Published: April 2005

The trace element contamination in the groundwater of District Hardwar in the state of Uttaranchal (India) has been assessed to find the suitability of groundwater for drinking purpose. Forty‐eight groundwater samples from shallow and deep aquifers were collected during both pre‐ and postmonsoon seasons in 2002 and analyzed for Fe, Mn, Cu, Ni, Cr, Pb, Cd, and Zn. The presence of trace elements in groundwater was recorded in all samples, but these were not significantly higher. Water quality standards were violated for iron and manganese at certain locations. The concentration of iron varies from 210–7004 µg/L during the premonsoon season and from 163–6555 µg/L during the postmonsoon season against the maximum permissible limit of 1000 µg/L; that of manganese varies from 7.5–839 µg/L during the premonsoon and from 9–859 µg/L during the postmonsoon season against the limit of 300 µg/L. The concentration of copper, chromium, lead, cadmium, and zinc were well within the permissible limits in all samples from District Hardwar.
Waterborne Bacteria
Authors: Rosen Barry H.
Published: April 2005

Bacteria are so widespread that only the most general statements can be made about their life history and ecology. They are everywhere on the earth, even in the most hostile environments, including extremes of temperature, such as freshwater hot springs. Many live in water; however, they are also an important part of soils and live in and on plants and animals; others are parasites of humans, animals, and plants. Only a handful of waterborne bacteria cause diseases, usually by producing toxins. Most bacteria have a beneficial role in decomposing dead material and releasing nutrients back into the environment.
Water Quality Management and Nonpoint Source Control
Authors: Zhang Harry X.
Published: April 2005

Nonpoint source (NPS) pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human‐made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water.

Nonpoint source pollutants include (1) excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas; (2) oil, grease, and toxic chemicals from urban runoff and energy production; (3) sediment from improperly managed construction sites, crop and forest lands, and eroding stream banks; (4) salt from irrigation practices and acid drainage from abandoned mines; (5) bacteria and nutrients from livestock, pet wastes, and faulty septic systems; and (6) atmospheric deposition and hydromodification are also sources of nonpoint source pollution. NPS pollution is widespread because it can occur any time activities disturb the land or water. Agriculture, forestry, grazing, septic systems, recreational boating, urban runoff, construction, physical changes to stream channels, and habitat degradation are potential sources of NPS pollution. Careless or uninformed household management also contributes to NPS pollution problems. The most common NPS pollutants are sediment and nutrients. These wash into waterbodies from agricultural land, small and medium‐sized animal feeding operations, construction sites, and other areas of disturbance.
Water Quality Modeling—Case Studies
Authors: Ji Zhen‐Gang
Published: April 2005

Although a variety of models are available for studying water quality processes, it is still a complex task to select a model (or models) that best meets all (or most) of the study objectives. Model selection should be balanced among competing demands. Time and resources are always limited, to one degree or another, so the goal should be to identify the model(s) that addresses all of the important processes that affect the waterbody. Selecting a model that is too simple can result in lack of accuracy and certainty that are needed in decision making; selecting an overly complex model may result in misdirected resources, study delays, and increased cost.

It is helpful to ask the following questions during model selection:

What are the key hydrodynamic processes?

What are the water quality concerns?

What spatial and temporal scales are adequate for resolving these processes?

How will the model be used in supporting management decision making?

It might be desirable to select the simplest model that can meet the study needs. However, in real practice, comprehensive models are often preferred to simple models for a variety of reasons. Typical features of comprehensive models include

three‐dimensional (3‐D) in space and time dependent

turbulent scheme for vertical mixing

hydrodynamic, thermal, sediment, and eutrophication processes.
Water Quality Models for Developing Soil Management Practices
Authors: Zhang Harry X.
Published: April 2005

It is important to estimate the collective impacts of all management activities in a watershed to evaluate whether water quality goals will be achieved. In watersheds that have easily characterized problems, it may be easy to project that water quality benefits will be achieved by implementing management measures such as erosion and sediment control and runoff minimization. However, in a watershed that has multiple land uses where agriculture is considered to contribute groups of pollutants, it is more complicated to estimate the combined impacts of a variety of management measures and practices on a fairly large number of diverse farming operations. In this type of situation, computer modeling may be needed. A variety of models exist to help assess the relative benefits of implementing practices at the field and watershed level. Managers can use models to develop goals and objectives for watershed and waterbody use and protection, to develop and to evaluate the effectiveness of various management and mitigation alternatives to improve existing water quality, and to determine the response time of a waterbody after implementing a management alternative. In particular, models can help understanding key “cause‐and‐effect” processes within the natural environment, developing waste load allocations and TMDL analysis, and evaluating the effectiveness of various contaminant reduction scenarios.
Whole Effluent Toxicity Controls
Authors: Markle Philip J.
Published: April 2005

The selection of an appropriate control sample/water for whole effluent toxicity testing is a critical experimental design component. Whole effluent toxicity (WET) testing has been an important tool for toxicity compliance and research testing alike to identify acute and chronic toxicity in effluents and receiving waters. The U.S. EPA and others have developed several manuals detailing specific WET methods; many have been incorporated into the National Pollutant Discharge Elimination System (NPDES) permit program for compliance determination. The primary objective of these aquatic toxicity tests is to estimate a maximum “safe” concentration of toxic substances in a discharge or receiving water that will allow for normal growth and propagation of aquatic organisms. A typical WET test experimental design consists of exposing organisms under controlled laboratory conditions to a series of effluent, receiving water, and/or toxicant dosed samples and recording biological observations such as reproduction, growth, and survival.
Biochemical Oxygen Demand
Authors: Butkus Michael A. , Manous Joe D.
Published: April 2005

A vast number of organisms, primarily bacteria, survives and even thrives in an environment containing no oxygen. However, most living creatures with which we commonly interact are aerobic; they need oxygen to survive. Aerobic creatures include all of the higher life forms such as fish, birds, mammals, and reptiles, as well as simpler species such as some bacteria and protozoa. The 4.7 billion year development of the earth and the evolution of species in response to this development have created many types of ecosystems; most support a balance between the demands of aerobic organisms for oxygen and the availability of oxygen. These “balanced ecosystems” are found in aquatic, terrestrial, and atmospheric biomes.
Remote Sensing and
GIS
Application in Water Resources
Authors: Jain Sanjay Kumar
Published: April 2005

Remote sensing is a tool that permits accurate and real‐time evaluation, continuous monitoring or surveillance, and forecasts of inland water resources. Remote sensing systems are used to observe the earth's surface from different levels of platforms, such as satellites and aircraft, and make it possible to collect and analyze information about resources and environment across large areas. Remote sensors record electromagnetic energy reflected or emitted from the earth's surface. Different kinds of objects or features such as soils, vegetation, and water reflect and emit energy differently. This characteristic makes it possible to measure, map, and monitor these objects and features using satellite or aircraft‐borne remote sensing systems. Satellite imagery offers a number of advantages over conventional survey techniques:

areal synoptic coverage (gives areal information as against point information through conventional techniques)

repetitive global coverage (for monitoring change)

real‐time processing

sensing of surrogates rather than the desired specific observation

multispectral coverage

More automation, less human error.
Spot Prices, Option Prices, and Water Markets
Authors: Lee Terence R.
Published: April 2005

Markets in water rights do not operate only for buying and selling permanent water rights. Using a market makes available a variety of other tools for increasing the efficiency of water use. Among the most interesting of these tools is the use of spot markets and water use options or future markets. Both alternatives lead to a broadening of the market and to an increase in the number of participants on both the buyer and the seller sides of the market. Their use also results in more stable demand and supply conditions as the market has a larger number of buyers and sellers. They also permit water users to hedge against changes in the price and availability of water rights and thus eliminate the need to hoard as a hedge against this risk. On the other hand, the use of spot and option or future markets requires developing storage facilities and interconnected conveyance systems if their full benefits are to be obtained.
State and Regional Water Supply
Authors: Downs Timothy J.
Published: April 2005

Integrated watershed management (IWM) seeks to combine interests, priorities, and disciplines as a multistakeholder planning and management process for natural resources within a watershed ecosystem, centered on water quantity and water quality. Driven bottom‐up by local needs and priorities and top‐down by regulatory responsibilities, it must be adaptive, evolving dynamically as conditions change. Water resource spatial and political scales range from local/municipal, subregional, state, regional (multistate), national, multinational (‘regional’ in a global sense) to continental and global. Large watersheds occupy state and regional spatial scales, presenting considerable challenges for IWM and water supply, in particular, because of the number and diversity of human consumers and biodiverse habitat needs.

A watershed spatial scale is often used by ecologists to analyze species distribution and biogeochemical cycling. Watersheds can be characterized by the proportions of land area taken up by five main land use/land cover categories: urban land, agricultural land, rangeland, forestland, and water. It is arguable whether a watershed or ecoregion scale (region of relative homogeneity based on soil, climate, and vegetative criteria) is most appropriate for managing water quality and aquatic habitats. Even in terms of water stocks and flows, the differences between precipitation and evapotranspiration in one watershed that determine the runoff and infiltration that can be used for water supply are influenced by regional climatic and hydrological processes.
Urban Water Resource and Management in
A
sia:
H
o
C
hi
M
inh
C
ity
Authors: Duc Hiep N.
Published: April 2005

The Ho Chi Minh City Service of Communication and Public Works (SCPW) admitted in September 1998 that the city's decades‐old water supply system cannot meet the growing demand. According to the SCPW, the water consumption is estimated at 800,000 m
3
per day, but the combined daily capacity of its two water plants at Thu Duc and Hoc Mon and underground wells stops short at 750,000 m
3
. But just only 500,000 m
3
is available to users each day after water loss in delivery is taken into account (the proportion of water loss is as high as 32% in some areas). However, in 2000, the daily demand jumped to 1,250,000 m
3
/day but the Water Supply Company can provide only 850,000 m
3
/day.
Water Demand Forecasting
Authors: Renzetti Steven J.
Published: April 2005

There are several issues surrounding the general practice of water demand forecasting. Boland (1) points out that any forecast has two essential components: explanation and prediction: “Explanation of water use usually takes the form of a model that relates the past observed level of water use to various variables. Replacing past values of the explanatory variables with those expected in the future produces a prediction of future water use” (pp. 162–163). Historically, the first of these two tasks—explaining water use—has been done by using ‘fixed‐coefficient’ models. In this approach, it is assumed that water use is related to a single explanatory factor such as population and, further, that the relationship between water use and population is a fixed, proportional one. Dziegielewski (2), for example, provides a brief review of the history of urban water demand forecasting and demonstrates that, in the ‘traditional’ method of forecasting, total future demand is predicted as the product of expected population growth and a fixed per capita water use coefficient. This method was subsequently refined by disaggregating total water use by user classes, area, and time period. The fundamental forecasting method remained the same, however; ‘unit water use coefficients’ is multiplied by the projected growth in a particular user group in a specific location. The fundamental shortcoming of the fixed coefficient approach is that it fails to anticipate changes in the relationship between water use and the dominant explanatory variable that may arise from changes in other, neglected variables. For example, forecasts of residential water use that are based on the number of households in an area may overstate future water demands if they neglect the impacts of rising water prices. More recently, more complex models have sought to estimate statistically the relationship between water use and a set of explanatory variables, including water prices.
Water Resources of India
Authors: Jain Sharad K.
Published: April 2005

With a geographic area of 3.29 million square km, India is an important country of Asia. India is bounded by snow capped Himalayas mountain chain in the North and has Indian Ocean in the south. The country has large variations in climate: at some places summer temperature can go up to 47°C while the temperature can go below −40° C at some places in Himalayas. Most of the precipitation is received through southwest and northeast monsoons. About 80–90% of precipitation is received through southwest monsoon during the months of June to September. Such a skewed temporal distribution of water availability makes it necessary to adopt water conservation measures on a large scale. The population and industrial activities in India are growing rapidly and due to this, sustainable water resources management is a challenging task in India.
Water Resource Sustainability: Concepts and Practices
Authors: Downs Timothy J.
Published: April 2005

The most famous definition of sustainable development is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (1). This unifying concept was the theme of the 1992 Earth Summit in Rio de Janeiro that produced the so‐called Blueprint for Sustainable Development,
Agenda 21
(2). At the core of the sustainability paradigm is the desire to reframe the perceived competition between development and environment (economy vs. ecology) into new forms of development ethics, thought, practice, and policy, reconciling enhancement of the quality of (human) life and social well‐being with the conservation of ecological integrity. Underpinning this lofty goal was the ethical pursuit of a more equitable society both today (intragenerational equity)
and
in the future (intergenerational equity). The term
sustainable development
is somewhat of an oxymoron because it implies stability, yet change, and begs the coupled questions: What to sustain, for how long, and for whom? This has led to confusion and a plethora of debate over the conceptual validity of the model. A useful working definition of a sustainable project, program, practice, or policy is one that yields a steady stream of benefits (or positive impacts) that exceed costs (negative impacts) over intergenerational timescales (25 years and beyond), while conserving ecological integrity.

Too much talk of “achieving” sustainable development has led to some disenchantment with the concept when it is not delivered, or even approximated. The real power of the sustainable development idea lies in its ability to change the way we think about intra‐ and intergenerational equity and our responsibility as custodians of biodiversity (3). It is much more helpful to view sustainability as a
relative
, dynamic state of development practice, one that can be degraded or improved substantially, but never reached absolutely.
Drought and Water Supply Management
Authors: Grigg Neil S.
Published: April 2005

Drought is a normal, albeit extreme, aspect of hydrologic variation, so it should be considered when making plans for water. Planning for water supply management involves both supply augmentation and demand management. Supply augmentation can involve new supplies or extending use of existing supplies.
Water Use Conservation and Efficiency
Authors: Buenfil‐Rodriguez Mario O.
Published: April 2005

Water has many uses and users, ranging from fluvial navigation to employing water as a component in a chemical experiment. On a global level, the four most water demanding human activities are energy—hydroelectricity—generation, irrigation for agriculture, urban supply, and nonurban industrial production. Each of them requires huge quantities of water and in its usage at least some water characteristic is affected, which limits the options of the remaining users to profit from that same water. This causes a competition in which each user would like to have exclusive rights to manage and exploit the resource. Hydroelectricity affects the potential energy of water (topographic elevation), and the other three basically affect water quality. There is a fifth user, frequently neglected by humans, which has the most ancient right to benefit from water, nature. The natural world needs water in lakes, forest, woods, floods, and climate regulation and has been greatly affected by the human desire to conquer and transform and to grow and expand.
Water Use in the
U
nited
S
tates
Authors: Lasserre Frédéric
Published: April 2005

Total water withdrawals in the United States are estimated at 402 billion gallons per day (Bgal/day) in 1995. This is 1.5% less than withdrawals for 1990 and confirms an overall stabilization of withdrawals throughout the country since 1975. That was the first time that withdrawals growth stopped outpacing population increases, implying an intensification of the use of water withdrawn. All major users, thermoelectric, irrigation, and industrial uses, saw their withdrawals stabilize; rural (domestic and livestock) and urban use, on the contrary, witnessed an ongoing trend of withdrawal increase.
Drought Management Planning
Authors: Grigg Neil S.
Published: April 2005

It is impossible to “manage” a naturally occurring drought, so “drought management” refers to managing resources, including water, to mitigate the adverse effects of droughts, which are certain to occur. Other resources that can be managed are food supplies, including animal feed, public facilities of various kinds, and economic resources to aid businesses, farmers, and citizens.
Effluent Water Regulations in Arid Lands
Authors: Meyerhoff Richard , Gensemer Robert , Markwiese James T.
Published: April 2005

This article addresses the regulation of water resources in arid environments and focuses on the special considerations of effluent‐driven ecosystems. Effluent serves as an increasingly important aquatic resource in the arid West, and the application of existing regulations for natural systems to effluent‐based bodies of water is receiving greater scrutiny. Issues affecting regulation of effluent include defining appropriate attainable beneficial uses for these created ecosystems, net ecological benefits of effluent discharge, and impacts from the modification of extant flow regimes resulting from effluent addition. The practical application of regulations in effluent‐driven ecosystems depends on recognizing these key issues.
Landfill Leachates,PartI: Origin and Characterization
Authors: Zouboulis A.I. , Samaras P.
Published: April 2005

Sanitary landfilling is the most widely used method for disposing of urban solid wastes around the world. The extensive use and the public awareness of this disposal method have raised concerns, over the negative environmental impacts and the pollution potential that this practice creates, as well as by the by‐products of landfills (e.g., leachates, biogas, odors, etc.). Among them, leachates are considered the most important environmental burden. Depending on the composition and extent of decomposition of the disposal of refuse, as well as on the hydrological parameters existing in the landfill site, leachates may become highly contaminated wastewaters.

Landfill leachate, as defined in the U.S. Environmental Protection Agency Code of Federal Regulations (CFR) Title 40, Part 258.2, is the liquid that has passed through, or emerged from the disposal of solid wastes and contains soluble, suspended, or miscible materials from these wastes. Over time, the seepage of water through the landfill mainly from precipitation increases the mobility of pollutants and the potential for transferring them into the surrounding environment. As water passes through the layers of disposal of solid wastes, it may “leach” pollutants from them, moving them deeper into the soil.
Air Stripping
Authors: Kuo Jeff
Published: April 2005

Air stripping is a physical process that enhances volatilization of compounds from water by passing clean air through it. It is commonly used in treating groundwater contaminated with volatile organic compounds (VOCs) and in removing ammonia in wastewater.
Metal Speciation and Mobility as Influenced by Landfill Disposal Practices
Authors: Ashworth Samuel C.
Published: April 2005

The precipitation that enters landfill wastes interacts with waste components and leaches metals and other substances. There are very complex interactions between the leachate and waste components that depend on pH, the metal and other component speciation, the presence of ligands, overall waste composition, redox potential, and others. Most of the leachate is collected in the leachate collection and treatment system. However, some of the leachate penetrates the bottom liner system from mechanisms similar to infiltration, and enters the soil column, and subsequently enters the groundwater.

Metal speciation and mobility are influenced by physical, chemical, and biological processes, and complex interactions between these processes may result in transporting specific contaminants at different rates. Attenuation of mobile metals depends on the amount of time that the contaminant is in contact with the material, the physical and chemical characteristics of the material, and the characteristics of the leachate.
Microbial Foaming and Bulking in Activated Sludge Plants
Authors: Stainsby Fiona M. , Philp James C. , Dunbar Sandra , Ivshina Irena B. , Kuyukina Maria S.
Published: April 2005

Microbial foaming and bulking are among the most frequent and widespread problems in activated sludge (AS) wastewater treatment plants (WWTPs). Bulking has plagued AS plants almost since their inception nearly a century ago, whereas microbial foaming was not documented until around 30 years ago. Both problems are associated with the excessive growth of various filamentous bacteria, although the mechanisms by which they form are not fully understood. Initial attempts to identify these bacteria shifted attention from engineering aspects to the microbiological activities fundamental to the activated sludge process. Subsequently, filament identification keys and abundance scales became routine tools for monitoring filamentous populations in activated sludge. More recently, molecular biological techniques have enabled more detailed and precise study of the diversity and ecology of bacterial communities associated with foaming and bulking.