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Ground Water Resources (ground + water_resources)

Distribution by Scientific Domains

Engineering	85%
Earth and Environmental Science	14%

Selected Abstracts

DECISION SUPPORT SYSTEM FOR MANAGING GROUND WATER RESOURCES IN THE CHOUSHUI RIVER ALLUVIAL IN TAIWAN,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2004
Chen Wuing Liu
ABSTRACT: Ground water is a vital water resource in the Choushui River alluvial fan in Taiwan. A significantly increased demand for water, resulting from rapid economic development, has led to large scale ground water extraction. Overdraft of ground water has considerably lowered the ground water level, and caused seawater intrusion, land subsidence, and other environmental damage. Sound ground water management thus is essential. This study presents a decision support system (DSS) for managing ground water resources in the Choushui River alluvial fan. This DSS integrates geographic information, ground water simulation, and expert systems. The geographic information system effectively analyzes and displays the spatially varied data and interfaces with the ground water simulation system to compute the dynamic behavior of ground water flow and solute transport in the aquifer. Meanwhile, a ground water model, MODFLOW-96, is used to determine the permissible yield in the Choushui River alluvial fan. Additionally, an expert system of DSS employs the determined aquifer permissible yield to assist local government agencies in issuing water rights permits and managing ground water resources in the Choushui River alluvial fan. [source]

Perspectives on Turkish Ground Water Resources

GROUND WATER, Issue 3 2003
Hasan Yazicigil
No abstract is available for this article. [source]

Perspectives on Mexican Ground Water Resources

GROUND WATER, Issue 6 2002
Luis E. Marin
No abstract is available for this article. [source]

Perspectives on Japanese Ground Water Resources

GROUND WATER, Issue 4 2002
Katsuyuki Fujinawa
No abstract is available for this article. [source]

Ground Water Sustainability: Methodology and Application to the North China Plain

GROUND WATER, Issue 6 2008
Jie Liu
This article analyzes part of a ground water flow system in the North China Plain (NCP) subject to severe overexploitation and rapid depletion. A transient ground water flow model was constructed and calibrated to quantify the changes in the flow system since the predevelopment 1950s. The flow model was then used in conjunction with an optimization code to determine optimal pumping schemes that improve ground water management practices. Finally, two management scenarios, namely, urbanization and the South-to-North Water Transfer Project, were evaluated for their potential impacts on the ground water resources in the study area. Although this study focuses on the NCP, it illustrates a general modeling framework for analyzing the sustainability, or the lack thereof, of ground water flow systems driven by similar hydrogeologic and economic conditions. The numerical simulation is capable of quantifying the various components of the overall flow budget and evaluating the impacts of different management scenarios. The optimization modeling allows the determination of the maximum "sustainable pumping" that satisfies a series of prescribed constraints. It can also be used to minimize the economic costs associated with ground water development and management. Furthermore, since the NCP is one of the most water scarce and economically active regions in the world, the conclusions and insights from this study are of general interest and international significance. [source]

Estimating Ground Water Recharge from Topography, Hydrogeology, and Land Cover

GROUND WATER, Issue 1 2005
Douglas S. Cherkauer
Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%. [source]

Quantifying Ground Water Recharge at Multiple Scales Using PRMS and GIS

GROUND WATER, Issue 1 2004
Douglas S. Cherkauer
Management of ground water resources requires a method to calculate demonstrably accurate recharge rates at local to regional scales using readily available information bases. Many methods are available to calculate recharge, but most are unable to satisfy all these conditions. A distributed parameter model is shown to meet the stated needs. Such models are input intensive, however, so a procedure to define most inputs from GIS and hydrogeological sources is presented. It simplifies the PRMS calibration observed streamflow hydrographs by reducing degrees of freedom from dozens to four. For seven watersheds (60 to 500 km2), the GIS-aided calibrations have average errors of 5% on recharge and 2% on total streamflow, verifying the accuracy of the process. Recharge is also calculated for 63 local-scale subwater-sheds (average size 37 km2). For the study area, calculated recharges average 11 cm/yr. Soil and rock conductivity, porosity, and depth to the water table are shown to be the physical properties which dominate the spatial variability of recharge. The model has been extended to uncalibrated watersheds where GIS and climatic information are known. It reproduces total annual discharge and recharge to within 9% and 10%, respectively, indicating the process can also be used to calculate recharge in ungauged watersheds. It has not been tested outside the study area, however. [source]

Salinization of a Fresh Palaeo-Ground Water Resource by Enhanced Recharge

GROUND WATER, Issue 1 2003
F.W. Leaney
Deterioration of fresh ground water resources caused by salinization is a growing issue in many arid and semi-arid parts of the world. We discuss here the incipient salinization of a 104 km2 area of fresh ground water (<3000 mg/L) in the semiarid Murray Basin of Australia caused by widespread changes in land use. Ground water 14C concentrations and unsaturated zone Cl soil water inventories indicate that the low salinity ground water originated mainly from palaeo-recharge during wet climatic periods more than 20,000 years ago. However, much of the soil water in the 20 to 60 m thick unsaturated zone throughout the area is generally saline (> 15,000 mg/L) because of relatively high evapotranspiration during the predominantly semiarid climate of the last 20,000 years. Widespread clearing of native vegetation over the last 100 years and replacement with crops and pastures leads to enhancement of recharge rates that progressively displace the saline soil-water from the unsaturated zone into the ground water. To quantify the impact of this new hydrologic regime, a one-dimensional model that simulates projected ground water salinities as a function of depth to ground water, recharge rates, and soil water salt inventory was developed. Results from the model suggest that, in some areas, the ground water salinity within the top 10 m of the water table is likely to increase by a factor of 2 to 6 during the next 100 years. Ground water quality will therefore potentially degrade beyond the point of usefulness well before extraction of the ground water exhausts the resource. [source]

Chemical and Isotopic Constraints on the Origin of Wadi El-Tarfa Ground Water, Eastern Desert, Egypt

GROUND WATER, Issue 5 2000
M. Sultan
We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River. Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L. Values of ,D and ,18O range from -10 to +34 %o and -2 to +5.2 %o, respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about ,D = -15 %o on a plot of 8D versus ,18O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River water. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium unite), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation. [source]

Effects of Rainfall and Ground-Water Pumping on Streamflow in M,kaha, O'ahu, Hawai'i,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2007
Alan Mair
Abstract:, Land-use/land-cover changes in M,kaha valley have included the development of agriculture, residential dwellings, golf courses, potable water supply facilities, and the introduction of alien species. The impact of these changes on surface water and ground water resources in the valley is of concern. In this study, streamflow, rainfall, and ground-water pumping data for the upper part of the M,kaha valley watershed were evaluated to identify corresponding trends and relationships. The results of this study indicate that streamflow declined during the ground-water pumping period. Mean and median annual streamflow have declined by 42% (135 mm) and 56% (175 mm), respectively, and the mean number of dry stream days per year has increased from 8 to 125. Rainfall across the study area appears to have also declined though it is not clear whether the reduction in rainfall is responsible for all or part of the observed streamflow decline. Mean annual rainfall at one location in the study area declined by 14% (179 mm) and increased by 2% (48 mm) at a second location. Further study is needed to assess the effect of ground-water pumping and to characterize the hydrologic cycle with respect to rainfall, infiltration, ground-water recharge and flow in the study area, and stream base flow and storm flow. [source]

DECISION SUPPORT SYSTEM FOR MANAGING GROUND WATER RESOURCES IN THE CHOUSHUI RIVER ALLUVIAL IN TAIWAN,

Salinity-related desertification and management strategies: Indian experience

LAND DEGRADATION AND DEVELOPMENT, Issue 4 2009
G. Singh
Abstract High concentration of salts in the rootzone soil limits the productivity of nearly 953 million ha of productive land in the world. Australia, followed by Asia, has the largest area under salinity and sodicity. Most of the salt-affected soils and brackish ground water resources are confined to arid and semiarid regions and are the causative factors for triggering the process of desertification. The problem of salinity and sodicity has degraded about 6·73 million ha area in India. Secondary salinization associated with introduction of irrigation in dry areas like Thar desert in the western part of the country and Sharda Sahayak in Central India have caused desertification due to rise of salts with the rise in ground water level. Large scale cultivation of prawns using sea water in coastal Andhra Pradesh and elsewhere rendered about 2.1 million ha area unfit for agriculture. Similarly, 30,84 per cent ground water in north-western states of the country is either saline and /or brackish and is unfit for irrigation. Use of marginal quality water for irrigation has rendered several thousand ha of productive land unfit for cultivation. The Central Soil Salinity Research Institute was established in 1969 at Karnal to develop sustainable and eco-friendly technologies for reclamation and management of salt-affected soils and judicious use of marginal quality waters. The institute has developed location-specific techniques for reversion of salinity related desertification in India. Salient findings of research during the last three decades and more are presented in this review. This paper deals with (a) classification, nature and extent of salt-affected soils and poor quality water in India, (b) case studies/socio-economic concerns of salinity related desertification, (c) chemical, hydrological and biological approaches in use for rehabilitation of salt-affected soils, (d) guidelines for safe and productive use of marginal quality ground water through cyclic and mixed mode and precision irrigation techniques, (e) successful rehabilitation case studies, (f) alternate land use practices such as raising forest plantations, horticulture, agroforestry, high value medicinal, aromatic and flowering crops, etc., (g) technological, social, economic and environmental impacts and (h) future line of research. Issues requiring policy initiatives to halt salinity-related desertification are also discussed in this review paper. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Water Resource Development in the Quaternary Ryukyu Limestone Regions of Japan: Application of the GIS to the Site Selection of Underground Dams

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2001
Kaijun JIANG
Abstract Based on the natural and social conditions as well as hydrogeological characteristics of the Ryukyu limestone, a major aquifer in the Ryukyu Islands, a conception of underground dam, was proposed in the early 1970s in order to develop ground water resources in the Quaternary Ryukyu limestone regions of Japan. The practice of nearly thirty years has shown that the underground dam is an environment-friendly and effective way for developing ground water in these regions. To further improve the technology associated with underground dam, the authors introduced related analytic methods. The application of the geographical information system technology to site selection of the underground dam is reported in this paper. [source]