bluuebunny/crossref_metadata_2025_split huggingface dataset:
Consolidated Water Bearing Rocks
Authors: Priyadarshi Nitish 
Published: April 2005

Abstract
Consolidated rocks (otherwise known as bedrock) consist of rock and mineral particles of different sizes and shapes that have been welded together by heat and pressure or chemical reaction into a rock mass. Aquifers of this type are commonly composed of one or more of the following rocks: sandstone, limestone, granite, or lava. Water flows through these rocks through fractures, gas pores, and other openings in the rock.
Consolidated rocks are usually classified according to their origin. There are three types: sedimentary, igneous, and metamorphic.
Sedimentary rock is formed by the deposition of material suspended in water; the material may have been material weathered from older rocks, plant or animal remains, or precipitated chemicals. Important types of sedimentary rock aquifers include sandstone, carbonate rock, and conglomerate.
Subsurface Drainage
Authors: Chauhan Harendra S. 
Published: April 2005

AbstractThe basic reason for agricultural lands to be affected by waterlogging and salinity is the inadequacy of the natural drainage system to handle the water that reaches the land either by natural or artificial means. Under such situations, an artificial drainage system has to be provided. The meaning of land drainage varies in different regions and contexts. A geographer or a surface hydrologist may use it to mean the pattern of natural watercourses in a hilly area. A pedologist may think in terms of the permeability of a poorly drained or well‐drained soil. In Peru, engineers interpret drainage as reconstruction of natural waterways rather than removal of water. In Canada, it may mean reclamation of marshland for agricultural or urban development. In Holland, a Dutch farmer may use it for the installation of drainpipe in the soil. Thus, in different areas, this term implies different meanings and objectives. If the land use is primarily agricultural then land drainage could be defined as the establishment and operation of a system by which the flow of water from the soil is enhanced, so that agriculture can benefit from the subsequently reduced or controlled water level in the soil. Agricultural land drainage aims at reclaiming and conserving land for agriculture, to increase crop yields, to permit cultivating more than one crop in an area, and to reduce the cost of production.
Viscous Flow
Authors: Hanspal Navraj S. , Nassehi Vahid , Das Diganta Bhusan 
Published: April 2005

AbstractThis text describes the elementary concepts of viscous fluid flow. The principal laws that govern the motion of fluids are also discussed. From our common experience, we know that fluids deform under the action of external forces. The deforming forces and rate of deformation are related to each other through a proportionality constant known as the coefficient of viscosity. The value of this constant depends upon the chemical identity, material properties, and thermodynamic state of a given fluid. To develop a theory that shows how viscosity affects fluid dynamics, one must understand the relationships between stress and the rate of strain. The outlines given in this article provide basic concepts of viscous flow. For more detailed analysis, the reader should consult specialized texts on this topic. Some of these texts are listed in the references at the end of this article.
Water Dowsing (Witching)
Authors: Commander David P. 
Published: April 2005

Abstract
‘Water dowsing’ is the supposed ability to locate underground water using a simple hand‐held device such as a forked stick, bent wires, or a plumb bob. ‘Dowsing’ is the general term applied to ‘divining’ for objects or materials concealed beneath the ground. Divining, or divination, implies a supernatural intervention and has been practiced for at least 2000 years for a variety of purposes. Water dowsing is also known as water witching.
Water Well Drilling Techniques
Authors: Jacobs James A. 
Published: April 2005

Abstract
Water well installation, for groundwater monitoring projects or for water supply wells for irrigation or human consumption involves a variety of drilling techniques. Rig selection is related to accessibility, time and cost of project, sediment type (consolidated rock or unconsolidated soils), sample type (undisturbed vs. disturbed), and sample integrity. For environmental projects, designing wells and evaluating groundwater also involves assessing the soil, sediments, or rocks above and below the water table.
Darcy's Law
Authors: Holden Joseph 
Published: April 2005

AbstractDarcy's law is a mathematical relationship originally determined by Henry Darcy in 1856 that permits quantification of fluid flow through porous media. Many sophisticated theoretical and practical derivations have been based on Darcy's law, and it has become the foundation for quantitative groundwater flow science and soil physics. In its most useful form, the formula can be used to calculate the amount of water (or other fluid) flowing through a given cross‐sectional area of a porous substance and equates volumetric discharge per unit time (q) to the product of area (A), hydraulic gradient (I = change in head per unit length) and a coefficient (K = saturated hydraulic conductivity). In its simplest terms, the relationship may be expressed asq = KIA.
Drawdown
Authors: Moore John E. 
Published: April 2005

AbstractAccording to Wilson and Moore, drawdown is the lowering of the water level in a well as a result of withdrawal. Drawdown data are collected to evaluate the performance of the well and to determine the aquifer's hydraulic character (transmissivity). Drawdown measurements also provide information on the well efficiency and performance. For example, measurements can be used with well discharge data to detect deterioration of the well screen.The drawdown in a pumping well is the sum of head loss factors. Some of the factors are natural processes, head loss in the aquifer, loss in the damage zone (well drilling), well development, and turbulent loss in the filter zone. The damage zone consists of drilling debris, filter cake, and drilling fluid.
Environmental Isotopes in Hydrogeology
Authors: Adelana S. M. A. 
Published: April 2005

Abstract
In the last three to four decades, environmental isotopes have contributed immensely to studies and investigations in hydrogeology, complementing physical and chemical hydrogeology. Many hydrogeologic studies use stable isotopes of the water molecule to determine groundwater quality, origin, recharge mechanism, and rock–water interaction. A goodly number of the applications of environmental isotopes in hydrogeology have been in the arid and semiarid areas of the world, where water scarcity is most acute and poses constraints on economic development. A substantial amount of basic data and results of applied field investigations have already been published on applications of different isotopes for hydrologic purposes.

Environmental isotopes provide indications of groundwater age and serve as natural traces for groundwater provenance. Stable isotopes of carbon, boron, nitrogen, and sulphur (i.e.,
13
C/
12
C,
11
B/
10
B,
15
N/
14
N, and
34
S/
32
S) can give valuable information about reactions involving these elements and can also serve as pollution tracers. On the other hand, radioactive isotopes of some of these elements decay, providing us with a measure of the circulation time and, invariably, groundwater renewability. The most common of the radioisotopes, carbon‐14, is used to estimate groundwater residence time. Isotopes of the uranium series (
234
U,
238
U,
226
Ra, and
222
Rn) are also useful tracers in isotope hydrogeology but are often not precise enough to establish the age of groundwater due to mineral–water interactions.
Field Capacity
Authors: Skopp Joseph 
Published: April 2005

Abstract
Storage of soil water is important to soil flora and fauna, to hydrologic processes, and to a variety of soil physical properties. One element of soil water storage is an upper limit on water that is available for plant use, referred to as “field capacity.” This entry provides a history of the concept, its relation to soil water holding properties, predictive techniques for field capacity, applications, and failures of the field capacity concept.
Early researchers of plant water relations quickly realized that in water limited regions, the ultimate crop yield depended not only on the amount of rainfall received but on what portion of that rainfall was usable. Three key factors could reduce the usefulness of rainfall: runoff, drainage below the root zone, and evaporation. The net effect of rainfall, runoff, and drainage results in retention of water in the root zone. Evaporation and transpiration reduce this retained water. This retention was studied by Veihmeyer and Hendrickson. The concepts developed by Veihmeyer and Hendrickson provide a means to evaluate whether a soil retains sufficient water to support a particular crop.
Fluoride Contamination in Ground Water
Authors: Jain Chakresh K. 
Published: April 2005

Abstract
Fluoride occurrence in ground water is a natural phenomenon, influenced by the local and regional geological setting and hydrogeological conditions of the region. Fluoride content much higher than the maximum permissible limit has been found in many regions throughout the world. The problem assumes more significance in India and other developing countries because a major portion of the population that lives in rural as well as urban areas have to depend on available groundwater resources for their day‐to‐day requirements. An estimated 62 million people in 17 out of 32 states are affected with dental, skeletal, and/or nonskeletal fluorosis in India. The extent of fluoride contamination varies from 1.0 to 48.0 mg/L.
Geological Occurrence of Groundwater
Authors: Moore John E. 
Published: April 2005

Abstract
The occurrence, movement, and storage of groundwater are controlled by geology. The geologic factors that control groundwater are petrography, stratigraphy, structure, geomorphology, lithology, and thickness. The petrography of a given rock type controls the porosity and permeability. Porosity defines the storage capacity of an aquifer. There are two types of porosity: primary and secondary. Primary porosity, such as pores between sand grains, is created when rocks are formed. The shape, sorting, and packing of grains determine primary porosity. Sedimentary rocks are poorly sorted when the grains are not the same size creating spaces between the larger grains that are filled by smaller grains. Secondary porosity such as joints, fractures, and solution opening, is formed after the rock has been deposited. The number and arrangement of fracture openings and the degree to which they are filled with fine‐grained material control secondary porosity.
Groundwater Dating with
H
–
He
Authors: Divine Craig E. , Humphrey John D. 
Published: April 2005

Abstract

During 1951, it was demonstrated that significant energy is released during hydrogen fusion to provide the basis for developing thermonuclear superbombs. Atmospheric testing (detonation) of these weapons during the next decade resulted in a dramatic increase in atmospheric
3
H concentration, until implementation of a Soviet–American atmospheric test ban treaty in 1963 (Fig. 2). Atmospheric thermonuclear weapons testing released vast quantities of high‐energy neutrons that interacted with
14
N and led to the production of
3
H (Eq. 1). The incredible amount of
3
H produced in the atmosphere resulted in a distinct precipitation input signal of anthropogenic
3
H (Fig. 3), and a notable peak in 1963.

The mid‐1960s
3
H peak has been widely used as a direct time marker to determine groundwater ages. However, because of the relatively short half‐life of
3
H, this peak has become difficult to differentiate in many systems. This is particularly true in the Southern Hemisphere where the anthropogenic
3
H in precipitation was notably lower than in the Northern Hemisphere. However, measurement of both parent
3
H and increases in its decay product,
3
He, can dramatically increase the sensitivity of the method.
Groundwater Dye Tracing in Karst
Authors: Bednar David M. 
Published: April 2005

Abstract
Groundwater dye tracing has proven to be an effective tool for aquifer characterization, protection, and to provide remediation strategies in karst areas. Tracing groundwater flow routes with fluorescent dyes is highly successful because they are water soluble and inexpensive. Fluorescent dyes are usually the best tracers to use in karst because they are easily detected in concentrations that are one to three orders of magnitude less than those at which nonfluorescent dyes can be measured spectrometrically. Additionally, they are safe to use, work effectively in different hydrogeologic settings, and can be used effectively to trace water from subsurface to surface water bodies. Dye tracing in karst has been used successfully to (1) delineate spring recharge areas and subsurface basins, (2) determine site‐specific hydrology, (3) estimate groundwater flow velocities, (4) trace groundwater flow from areas of recharge to discharge, (5) delineate wellhead protection areas, (6) map and characterize conduit flow routes, (7) detect leakage from residential sewage disposal systems, (8) identify sources of potential pollution from hazardous waste sites, (9) detect leakage from dam sites, and (10) characterize groundwater flow routes to important springs and cave streams along highway corridors.
Ambient Groundwater Monitoring Network Strategies and Design
Authors: Towne Douglas C. 
Published: April 2005

Abstract
Groundwater quality can be negatively impacted by a variety of physical features and cultural activities that are not always easily discerned by empirical observations. The detection and continued monitoring of groundwater quality constituents and contaminants requires expensive field sampling operations and laboratory analyses. Once deterioration of groundwater quality begins, it may be difficult to reverse, and treating the impacted water can be prohibitively expensive.
An ambient network is a proactive strategy that uses groundwater monitoring and characterization along with scientific methods and hydrologic models to assess holistically the groundwater of a given area, usually a defined hydrologic basin. Ambient networks are designed to identify regional changes in groundwater levels and/or degradation of groundwater quality such as occurs from widespread nonpoint sources of pollution or a high density of point sources. Information gleaned from an ambient network includes determining where groundwater levels are fluctuating, locating areas of poor water quality, and identifying spatial and temporal water quality patterns. When correctly designed, the data collected in ambient monitoring programs can be statistically analyzed to make broad statements about the groundwater of a basin that have a known degree of confidence using a relatively small number of investigated sites. Several states such as Arizona and Idaho (1) have redesigned their ambient networks because of subjective, rather than statistical, selection of sites. Others such as Minnesota (2) initiated new ambient networks because the previous design failed to meet objectives.
Aquifers
Authors: Harter Thomas 
Published: April 2005

Abstract
An aquifer is a geologic formation or geologic unit from which significant amounts of groundwater can be pumped for domestic, municipal, or agricultural uses. The four major types of rock formations that serve as aquifers are unconsolidated sand and gravel, sandstone, carbonate rocks, and fractured volcanic rocks. Aquifers may also occur in other geologic formations, particularly in fractured zones of igneous, metamorphic, or sedimentary rocks.
The word aquifer was probably adopted around the early twentieth century from the French word aquifère, which originates from the two Latin words aqua (water) and ferre (to carry, to bear). Hence, literally translated from Latin, aquifer means ‘that which carries water.’
There is no strict definition of the hydrogeologic attributes or volumetric extent necessary to make a geologic formation or geologic unit an aquifer. Rather, the term aquifer is used for local formations that have relatively higher permeability than surrounding formations. Geologic units that form an aquifer in one setting may therefore not be considered to constitute an aquifer in other settings.
Groundwater Tracing
Authors: Jahani Hamid R. 
Published: April 2005

Abstract
Groundwater tracing is now a major field in groundwater hydrology aiming mainly at demonstrating the direction of groundwater flow and secondly, at giving as much information on the hydrologic setting as possible. It has been used for several decades to study flow conditions, for groundwater reconnaissance, and for managing water resources. During the last decades, water protection has been one of the main issues due to strong pollution of the environment. A groundwater tracer is a substance or a sort of energy conveyed by water to be detected at a sampling point and to be used in analyzing the temporal and spatial distribution of water and the pollutant. Artificial and natural tracers can help in various ways to assess and to predict contaminant transport in surface and groundwater.
Hydraulic Properties Characterization
Authors: Loo Walter W. 
Published: April 2005

Abstract
Groundwater is becoming an important issue as a source of fresh water. The groundwater that exists at the subsurface is called an aquifer. An aquifer is a geologic unit that can store and transmit water at rates fast enough to supply reasonable amounts to wells. Thus, understanding a groundwater body is an essential factor in groundwater development and protection.
The geohydrologic properties of a groundwater body consist of physical, chemical, and biological parameters of the solid matrix and liquid within its pore space. These parameters determine the quantitative, qualitative, and interpretive aspects of the groundwater body. The solid matrix may consist of various sedimentary deposits or rock types. The liquid within the pore space of the groundwater body consists of water, dissolved minerals and gases, microorganisms, and colloidal material.
Assessment of Groundwater Quality in
D
istrict
H
ardwar,
U
ttaranchal,
I
ndia
Authors: Jain Chakresh K. 
Published: April 2005

Abstract

The groundwater quality of District Hardwar in the state of Uttaranchal (India) has been assessed to see the suitability of groundwater for domestic use. Forty‐eight groundwater samples from shallow and deep aquifers were collected each during pre‐ and postmonsoon seasons during the year 2002. Various water quality constituents, pH, conductance, total dissolved solids, alkalinity, hardness, sodium, potassium, calcium, magnesium, chloride, sulphate, phosphate, fluoride, total coliforms, and fecal coliforms were determined. The data were analyzed with reference to BIS and WHO standards, and hydrochemical facies were determined. The concentration of total dissolved solids exceeded the desirable limit of 500 mg/L in about 25% of the samples analyzed, but the values were well within the maximum permissible limit of 2000 mg/L. The alkalinity exceeded the desirable limit of 200 mg/L in about 50% of the samples, but these were also within the maximum permissible limit of 600 mg/L. From the hardness viewpoint, about 80–85% of the samples were within the desirable limits. One sample of the study area exceeded the maximum permissible limit of 100 mg/L for nitrate. Other constituents such as chloride, sulphate, and fluoride were within the desirable limits. The bacteriological analysis of the groundwater samples indicated bacterial contamination in about 40% of the samples analyzed. Inadequate maintenance of hand pumps, improper sanitation, and unhygienic conditions around the structure may be responsible for bacterial contamination in groundwater of the region and is a cause of concern. It is recommended that the water drawn from such sources be properly disinfected before being used for drinking and other domestic purposes. The grouping of samples according to their hydrochemical facies indicates that all the samples of the study area fall under Ca–Mg–HCO
3
hydrochemical facies.
In SituElectrokinetic Treatment ofMtBE, Benzene, and Chlorinated Solvents
Authors: Loo Walter W. 
Published: April 2005

AbstractThe basic mechanism of bioremediation is triggering the growth of microorganisms that are adapted to organic wastes spilled in the soil and groundwater. Stimulation of the growth of the microorganism is controlled by proper temperature, oxygen, moisture, nutrients, and cosubstrates, and distribution of such in the impacted media. During growth, the microorganism will secrete enzymes and biosurfactants to break down the hazardous organic molecules (detoxification) and to make them available through cellular absorption. Subsequently, the microorganism will grow and multiply, and the process repeats until the food source is depleted. The end result is mineralization of the carbon source (from spilled hazardous organic wastes) aerobically into carbon dioxide, water, and biomass without undesirable side effects. The cometabolic processes for bioremediation of chlorinated solvents and petroleum hydrocarbons are the most promising trouble‐free biotreatment processes and are very efficient. The cometabolic process can be defined as the introduction of an easily biodegradable substrate into the environment, which triggers the secretion of enzymes from microorganisms that are adapted to the spilled hazardous organic waste.
In Situ
Groundwater Remediation for Heavy Metal Contamination
Authors: Jacobs James A. 
Published: April 2005

Abstract
Remediation of heavy metals such as lead, chromium, arsenic, and others in soil and groundwater frequently uses reduction reactions to lower the solubility of an oxidized metal in the higher of two or three valence states to a lower energy and less toxic state. Ultimately, the metal is precipitated as a sulfide or in another immobile and low toxicity form.
The solubilities of arsenic, lead, copper, zinc, cadmium, molybdenum, uranium, and cyanide are pH dependent. Recently, sulfur‐based metals treatment technologies have been the focus of an increasing number of research studies and commercial applications for treating metal contamination in soil and groundwater.

In situ
metal remediation by reduction can be either chemical or biological. For chemical reactions, sulfur compounds have been used successfully in a variety of settings. Precipitation of metals in reducing environments as sulfides, hydroxides, and carbonates has been documented as a remediation method. Even zero‐valent iron has been used to reduce hexavalent chromium in groundwater through reactive permeable barrier walls, as part of a funnel and gate system. Reactive barriers for
in situ
metal treatment are documented.