bluuebunny/crossref_metadata_2025_split huggingface dataset:
Media Filters for Microirrigation
Authors: Haman Dorota Z. 
Published: July 2005

Abstract
Media (sometimes called sand) filters are well suited for removal of either organic or inorganic particles. Due to their three‐dimensional nature, media filters have the ability to entrap large amounts of contaminants. They do not seal off as easily and therefore will not clog as often as filters that trap particles on their surface, such as screen filters. Media filters consist of fine gravel and “sand” (that actually is crashed granite or silica) of selected sizes placed in pressurized tanks. The main body of the tank contains sand, which is the active filtering ingredient. The sand is placed on top of a thin layer of gravel that separates it from an outlet screen. Sharp‐edged sand or crushed rocks are recommended for the filtering media since the corners catch soft algal tissue. Crushed granite or silica graded into specific sizes for a particular system are commonly used porous media. Media filters are cleaned by backwashing. This operation consists of reversing the direction of water flow in the tank. Automatic back flush systems will eliminate sudden changes in water quality that can create problems if a filter is washed only at regular intervals.
Classification and Mapping of Agricultural Land for National Water‐Quality Assessment
Authors: Gilliom Robert J. , Thelin Gail P. 
Published: July 2005

Abstract
The U.S. Geological Survey's (USGS) National Water‐Quality Assessment (NAWQA) Program is designed to describe the status and trends in the quality of the nation's ground‐ and surface‐water resources and to link the status and trends with an understanding of the natural and human factors that affect the quality of water. The program integrates information about water quality at a wide range of spatial scales, from local to national, and focuses on water‐quality conditions that affect large areas of the nation or occur frequently within small areas.
Soil Conservation
Authors: Rickson R. J. , McHugh M. , Morgan R. P. C. 
Published: July 2005

Abstract
Soil is a precious natural resource, which performs many vital functions. As a growing medium, soil provides nutrients, air, and water to sustain life on earth, supporting global agricultural and manufacturing industries with renewable raw materials, enabling sustainable economic growth and prosperity. As a habitat, soil is an essential gene reservoir, maintaining a healthy biodiversity that enables micro‐ and macroorganisms to adapt successfully to environmental changes. Soil influences our natural and cultural landscapes by providing the foundation and raw materials for infrastructure, thus affecting the aesthetics of the world around us. Soils have enormous storage capacity, absorbing surface water, which helps to reduce flooding risk, and providing water supplies for agricultural, domestic, and industrial demands. Soil filters the water passing through it, and chemical transformations help neutralize potentially harmful substances. Soils also store nutrients, trace elements, and organic carbon. Soils are essential in the sequestration of carbon and in the absorption, storage, and reflection of solar energy—important processes that influence global climate and climate change.
Soil
N
Management Impact on the Quality of Surface and Subsurface Water
Authors: Sarkar Dibyendu , Vandanapu Vandana , Datta Rupali 
Published: July 2005

Abstract
Nitrogen (N) in the forms of nitrate or ammonium is a nutrient needed for plant growth. When the amount of soil‐supplied N is considered deficient for satisfactory crop yields, N fertilizer is added to supplement the soil‐supplied N. If N is supplied in excess of crop needs, a surplus is created that can cause significant water quality problems. Until recently, the main reason for investigations into the forms of N in soil systems below the rooting depth of plants was to evaluate the loss of nitrate to crops and to estimate the loss of production. In recent years, much attention has been focused on forms of N as potential pollutant sources of both groundwater and surface water. Nitrate concentrations above a certain level in drinking water may have critical health effects on animals and human infants. Alternately, N can also contribute to surface water contamination via surface water runoff and erosion. Excessive nitrate concentrations in surface water bodies, such as streams or lakes, can accelerate algae and plant growth, resulting in oxygen depletion. Nitrogen must be managed properly to protect water quality. Best management practices (BMPs) are methods that are the most effective, practical means of preventing or reducing nutrient pollution from nonpoint sources. Nitrogen BMPs primarily involve a change in fertilizer management practices, such as changing the timing, placement method, and/or the amount of fertilizer applied to reduce the possibilities of contaminating water resources. In addition, conservation tillage practices, cover crops, and crop rotation all help reduce surface runoff, erosion, and leaching of soil N. It is imperative to continue the development and implementation of new and effective management practices that increase N recovery and reduce potential N losses to the environment.
Waterlogging
Authors: Gupta Suresh K. 
Published: July 2005

AbstractIn its simplest form, waterlogging connotes congestion of drainage whether surface or subsurface. According to Webster's dictionary, waterlogging has been defined as follows: to saturate with water, as to waterlog soil by allowing stagnant water to stand on it; waterlogged, rendered soggy and unfit to till by water in excess of soil. Clayton has defined a land as waterlogged when the water table is within ±150 cm of the natural surface. A definition adopted in 1925 by the state of Punjab (India) designated land as waterlogged if it is thrown permanently out of cultivation due to a rise in subsoil water and is recorded asbanjar(barren) in the revenue records.
Water Spreading
Authors: Arasteh Peyman Daneshkar 
Published: July 2005

Abstract
Runoff farming is one of the most common techniques to supply some part of irrigation water in arid and semiarid areas of the world. For runoff farming, because of the lack of normal water supply, water harvesting techniques must be used, and one of these water harvesting methods is floodwater spreading. When rainfall intensity is more than infiltration and other catchment abstractions, surface runoff has occurred, and when the catchment natural waterways have a capacity less than runoff, flood has occurred. Flood spreading is a method to control the risks and hazards of floods, groundwater recharge, crop production, etc. In this article, flood spreading is mentioned as an irrigation method, and some aspects of the history of floodwater spreading, some design criteria, and some suitable references for designation of the system are introduced.
Domestic Solar Water Heaters
Authors: Smyth Mervyn 
Published: July 2005

Abstract
Solar water heating systems convert solar radiation into useable thermal energy in the form of hot water. Domestic solar water heaters can provide households with a large proportion of their hot water needs while reducing the amount of conventional fuel used and hence reducing home energy costs. The amount of hot water produced will depend on the type and size of the system, the climate, and location for solar access. Over the years, a variety of system designs have been developed and tested to meet specific consumer needs and environmental conditions.
Domestic solar water heaters can be categorized as being either active or passive and can be further grouped according to the configuration of the main solar water heating components: integral or distributed. Integrated systems combine the collector and storage functions in a single unit, whereas distributed systems have a separate solar collector and hot water store connected by a piping network. Distributed systems can be either active or passive. In active systems, a pump circulates the transfer fluid between the collector and the store. Integrated systems are almost always passive as they do not require external power.
Water Reuse
Authors: Cartwright, P.E. Peter S. 
Published: July 2005

Abstract

Water reuse
is the general term applied to the act of recovering water from a process and reusing it in the same process, or another one, before discharging it. Some experts attach labels to this activity based on the specific use of the water:
Recycle
involves redirecting the recovered water back to the same process.
Reuse
means reusing the recovered water in a different application.
Recovery
generally refers to the technologies used to accomplish this.
Household Drinking Water Treatment and Safe Storage
Authors: Murcott Susan 
Published: July 2005

Abstract
Household water treatment is the decentralized treatment of drinking water in the home and safe storage is the protection of drinking water in specially designated household storage vessels.
Even for the 50% of people worldwide with a tapped water supply, safety is not always assured. In such homes, household treatment units improve the aesthetics and/or remove harmful contaminants. Homes lacking a tapped drinking water supply are more likely to bear the burden of water‐related illnesses: 3.4 million deaths are water related; 1.4 million children die annually of diarrhea—the third highest cause of illness and sixth highest cause of mortality globally; and 1.1 billion—or about one in six people globally—lack access to improved drinking water.
For these people, household water treatment and safe storage may be their main barrier in the prevention of water‐related illnesses, and evidence shows that household treatment and safe storage systems are capable of dramatically improving the microbial quality of drinking water and reducing diarrheal and other water‐related diseases and death.
In the decade to come, we will witness innovation and scale‐up of these systems from hundreds to thousands to millions to meet the enormous global need for clean drinking water.
Corrosion Control in Drinking Water Systems
Authors: Volk Christian J. 
Published: July 2005

AbstractDrinking water distribution systems are primarily composed of iron and steel pipes or other metallic pipes that are subject to corrosion. Various metals, such as lead, copper, zinc, cadmium, and iron, may be present in water when metals corrode in the water systems. Depending on water quality, the source water either causes corrosion or deposition of a film on pipes and plumbing fixtures. Corrosion of distribution system pipes has economic, hydraulic, and aesthetic impacts including water leaks, corrosion product buildup, increased pumping cost, and water quality deterioration. Corrosion of iron is also the primary factor for controlling bacteria growth. Many systems have to provide corrosion control to comply with the federal and state regulations enacted to protect consumers from health dangers of lead and copper in drinking water. This article provides an overview of corrosion in the distribution system, factors impacting corrosion, corrosion measurement, and the need for corrosion control.
The Arsenic Drinking Water Crisis in
B
angladesh
Authors: Bryce Charlie , Philp Jim 
Published: July 2005

Abstract
Although the incidence of arsenic poisoning in groundwater is worldwide and includes Bangladesh and India, Taiwan, Vietnam, Chile, China, North America, and Finland, the area of the highest demand for a resolution of the problem is Bangladesh. The source seems to be geological, for arsenic has been found in tube well water used for drinking and irrigation, although the geochemistry is not completely understood. As many thousands of boreholes have been produced to support modern irrigation systems, the underground aquifers are aerated, which causes transformation of anaerobic conditions to aerobic conditions. The presence of oxygen in this way decomposes arsenopyrite‐releasing arsenic acid. At low pH, this arsenic dissolves in water and hence leads to water contamination. The arsenic content of sediments is high relative to crustal concentrations. The biogeochemical cycling of arsenic and iron are coupled in deltaic systems; iron oxyhydroxides act as a carrier for the deposition of arsenic in sediments. From there, it can be mobilized by bicarbonate, which can extract arsenic from sediments under both aerobic and anaerobic conditions.
Arsenic also becomes a pollutant as a result of various industrial uses and activities. Arsenic is a metalloid, and its primary usage has been in agriculture, in formulating herbicides, especially for controlling weeds in cotton fields. Sodium arsenite has been used as an insecticidal ingredient in sheep‐dips. In industry, arsenic has found use in glass manufacture and a new role in the semiconductor industry. Copper smelting releases significant amounts into soils.
Applications of Soil Vapor Data to Groundwater Investigations
Authors: Hartman Blayne , Jacobs James A. 
Published: July 2005

AbstractThis article describes the uses and interpretation of soil vapor data for a variety of common applications related primarily to groundwater. It begins with an overview of the applications of soil vapor surveys, a brief discussion of the various soil vapor methods, and then focuses on a number of specific issues relating to soil vapor surveys for groundwater investigations. The intent of this article is to guide professionals on when, why, and how soil vapor data can be useful for groundwater‐related investigations and how to interpret the results.
Connate Water
Authors: Brody Richard C. 
Published: July 2005

Abstract
Connate water is water trapped in the interstices of sedimentary rock (subsequently buried by younger sediments) or igneous rock when it was deposited. Connate water occurs as a film of water around each grain of sand in the rocks, is chemically or physically bound to the lithosphere (soil and rocks), and has existed since the rocks formed (also see Fossil Water). Although connate water resides in the rocks (interstitial or interstratal), it is not part of the groundwater system and does not play a role in the hydrologic cycle.
Sub‐Surface Redox Chemistry: A Comparison of Equilibrium and Reaction‐Based Approaches
Authors: Singhal Naresh , Islam Jahangir 
Published: July 2005

AbstractRedox reactions, which involve the transfer of electrons from one chemical species to another, play an important role in the subsurface environment. The knowledge of redox chemistry is essential to understanding the relationships among chemical speciation, mobilization, and toxicity. Redox reactions can be abiotic or biotic, and they may be described using the equilibrium or kinetic approaches. The equilibrium approach assumes that thermodynamic equilibrium has been established in the system and that the prevailing redox conditions can be described with equilibrium relationships for the various reactions. Although the equilibrium approach has been commonly used, many reactions in the subsurface environment, mostly heterogeneous reactions, progress slowly and do not conform to the equilibrium assumption. Such reactions are best described with the kinetic approach, which describes the reactions using kinetic expressions. However, our current understanding of kinetic processes is primitive. This article presents a summary of the various equilibrium and kinetic approaches that have been used in the literature to describe subsurface redox conditions.
Tidal Efficiency
Authors: Rasmussen Todd 
Published: July 2005

Abstract
Ocean tides often cause water levels in coastal aquifers to fluctuate. These fluctuations result from two different causes. In confined aquifers, the additional weight of the water on the surface increases the pressure on the water at depth, which causes an increase in water levels in observation wells located near the coast. In this case, no movement of water between the ocean and the aquifer may have occurred. In unconfined aquifers, however, the loading effect does not occur. Instead, water that has moved directly through the pores within the aquifer has caused the water level response. Regardless of the mechanism, both processes can be described with the phase lag, or delay, between the tidal peak and the aquifer response peak, as well as the amplitude ratio between the magnitudes of the response and the tides.
Transport of Reactive Solute in Soil and Groundwater
Authors: Capiro Natalie L. , Bedient Philip B. 
Published: July 2005

AbstractThe extensive impacts to soil and groundwater by contaminants such as chlorinated solvents and petroleum hydrocarbons can be attributed to their widespread use in the United States and to their persistence in the environment. Understanding the fate and transport of these pollutants and other solutes is essential for the protection of water supplies and successful field site remediation. Subsurface solute fate and transport is dictated by processes that fall into the general categories of hydrodynamic, abiotic, and biotic. Hydrodynamic processes that include advection and dispersion influence flow patterns through the vadose zone and in groundwater. Those processes that impact solute interactions with the surrounding aquifer matrix, such as sorption or the composition of the contaminant itself, are known as abiotic. The biotic category is variable based on available substrates and nutrients, but under certain favorable conditions, these microbial processes can have a profound impact on contaminant structures and their longevity in the environment. Transport processes are extremely difficult to quantify because of the vast heterogeneities encountered in the field; however, improving our comprehension continues to be an area of extensive research for many science and engineering fields.
Unconfined Groundwater
Authors: El‐kadi Aly I. 
Published: July 2005

AbstractAn unconfined aquifer is a geologic formation with subterranean water that is not confined by relatively impermeable layers. Part of the precipitation and irrigation water as well as water from recharge basins, reservoirs, and ponds moving downward from the soil layer will reach the saturated groundwater zone. The top of this zone is the water table, which separates the fully saturated zone from a partially saturated zone. The latter zone is simply referred to as the unsaturated zone, but it is also known as the zone of aeration or vadose zone. Generally, the water in the unsaturated zone is under less than atmospheric pressure. The unsaturated zone includes the capillary fringe, directly above the water table, which is near saturation but still under negative pressure relative to the atmospheric pressure.
Vadose Zone Monitoring Techniques
Authors: Rykwalder Philip R. , Blanford William J. 
Published: July 2005

AbstractMonitoring fluids of the vadose zone has multiple motives, including detecting contaminants, measuring soil properties and water conditions for construction or monitoring geologic hazards, and determinations of water saturation that may be used for optimizing irrigation. Because fluids must move through the vadose zone to reach the water table, monitoring of the vadose zone allows predicting possible sources and processes of groundwater contamination. Geologic hazards such as landslides, rising water tables, or land subsidence can be partially predetermined by monitoring the vadose zone. And in agriculture, monitoring soil water content to irrigate most efficiently has a long history.
Water in the Unsaturated Zone
Authors: Babel Mukand Singh 
Published: July 2005

Abstract
The soil profile immediately below the land surface and above the water table is called the unsaturated zone, where the pores contain both water and air. This zone differs from the saturated zone, where the pores are saturated with water. The unsaturated zone is sometimes called the vadose zone.
The thickness of an unsaturated zone can range from zero (e.g., when a lake or marsh is at the surface) to hundreds of meters, as is common in arid regions. It is a zone of natural and human‐induced activity. It experiences physical phenomena such as thermodynamic interactions, transport processes of various kinds, and chemical reactions involving both natural and artificial substances. Several biological activities involving plant roots, rodents, worms, microbiota, and other organisms also take place in this zone. The zone is used for cultivating plants, constructing structures, and disposal of waste.
To a large degree, the unsaturated zone controls the transmission of water to aquifers (water bearing strata), as well as to the land surface, to water on the surface, and to the atmosphere. It also acts as a filter as it removes undesirable substances before they reach and affect aquifers.
Well Test
Authors: Williams Dennis E. 
Published: July 2005

Abstract
Well tests are conducted in completed wells after development in order to collect information on the hydraulic parameters of the well and surrounding aquifers. Groundwater level data from the well tests are collected, compiled, and graphically plotted, and the data are evaluated using various methods to determine hydraulic parameters of the aquifer and well.
Step‐drawdown tests are generally the first type of test performed. This test involves pumping the well at several rates and measuring the change in water level as time progresses. Following the step‐drawdown test, a constant rate pumping test is usually performed. The well is pumped continuously at the design discharge rate over a longer period of time, usually more than 24 h, in order to estimate longer‐term drawdown effects. Recovery tests, carried out after pumping tests, involve measuring the rate at which the water level recovers to its initial level after pumping has stopped.
A slug test is a popular and inexpensive method of estimating the hydraulic properties of aquifers in small diameter wells when the hydraulic conductivity of the aquifer materials is too low to conduct a pumping test. This test involves rapidly adding or removing a “slug of water” from a well and measuring the rate at which the water level recovers.
Low Flow Groundwater Purging and Surging
Authors: Vance David B. , Jacobs James A. 
Published: July 2005

Abstract
Groundwater monitor wells are installed primarily as tools to measure the dissolved concentrations of contaminants in groundwater in and around facilities where the release of contaminants has occurred or where the potential exists for such a release to occur (i.e., adjacent to landfills). These wells are installed with the intention of obtaining an accurate assessment of the conditions in the formation adjacent to the well. A significant body of literature and guidance documentation exists concerning the location, drilling, installation, and development of those wells to that end. However, it has become evident that the quality of the data yielded from monitor wells is dependent on screen length and location (addressed during design and installation), purging method, and purge volume.
The use of screened hydraulic probes is recognized as an accurate sampling method and as the yardstick for comparison with various monitor well sampling techniques. Their practical use is of value for initial plume delineation and assessment in aid of the design of a monitor well network; however, they are impractical as a long‐term monitoring system. The groundwater monitor well is essential for that role.
Particulate Transport in Groundwater—Bacteria and Colloids
Authors: Vance David B. , Jacobs James A. 
Published: July 2005

Abstract

Evaluation of mass transport of entrained material in groundwater flow systems is typically focused on two primary areas, dissolved organic or inorganic species, and flowing free phase liquids. However, although generally not as dominant overall, the movement of small particles in groundwater can cause problems at the low concentrations required by regulatory limits. In addition, the proponents of
in situ
bioaugmentation, through injection of bacteria, must rely on successful particulate mass transport through the saturated soil matrix.