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Groundwater Resources (groundwater + resource)
Selected AbstractsUsing wind to power a groundwater circulation well,preliminary resultsREMEDIATION, Issue 4 2004Andrew Curtis Elmore In areas of the country where the U.S. Department of Energy has classified the available wind resources as Class 3 or greater, the use of wind turbines to provide power to relatively small remediation systems such as groundwater circulation wells may be technically and economically feasible. Groundwater circulation wells are a good candidate technology to couple with renewable energy, because the remediation system removes contamination from the subject aquifer with no net loss of the groundwater resource, while the wind turbine does not create potentially harmful air emissions. Wind data collected in the vicinity of the former Nebraska Ordnance Plant Superfund site were used to select a wind turbine system to provide a portion of the energy necessary to power a groundwater circulation well located in an area of high trichloroethylene groundwater contamination. Because utility power was already installed at the remediation system, a 10 kW grid inter-tie wind turbine system supplements the utility system without requiring batteries for energy storage. The historical data from the site indicate that the quantity of energy purchased correlates poorly with the quantity of groundwater treated. Preliminary data from the wind turbine system indicate that the wind turbine provides more energy than the remediation system treatment components and the well submersible pump require on a monthly average. The preliminary results indicate that the coupling of wind turbines and groundwater circulation wells may be an attractive alternative in terms of the system operation time, cost savings, and contaminant mass removal. © 2004 Wiley Periodicals, Inc. [source] Methyl- tert -hexyl ether and methyl- tert -octyl ether as gasoline oxygenates: Anticipating widespread risks to community water supply wells,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2007Jeff Snelling Abstract The widespread contamination of groundwater resources associated with methyl- tert -butyl ether (MtBE) use has prompted a search for replacement oxygenates in gasoline. Among the alternatives currently under development are higher methyl- tert -alkyl ethers, notably methyl- tert -hexyl ether (MtHxE) and methyl- tert -octyl ether (MtOcE). As was the case with MtBE, the introduction of these ethers into fuel supplies guarantees their migration into groundwater resources. In the present study, a screening-level risk assessment compared predicted well water concentrations of these ethers to concentrations that might cause adverse effects. A physicochemical model which has been successfully applied to the prediction of MtBE concentrations in community water supply wells (CSWs) was used to predict well water concentrations of MtHxE and MtOcE. The results indicate that these ethers are likely to contaminate water supply wells at slightly lower levels than MtBE as a result of migrating from leaking underground fuel tanks to CSWs. Because very little data is available on the physicochemical and environmental properties of MtHxE and MtOcE, estimation methods were employed in conjunction with the model to predict well water concentrations. Model calculations indicated that MtHxE and MtOcE will be present in many CSWs at concentrations approaching the concentrations that have caused widespread public health concern for MtBE. Based on these results and the possibility that MtHxE and MtOcE are potential carcinogens, testing of the toxicological properties of these ethers is recommended before they are used to replace MtBE in gasoline. [source] IHMS,Integrated Hydrological Modelling System.HYDROLOGICAL PROCESSES, Issue 19 2010Part 2. Abstract The integrated hydrological modelling system, IHMS, has been described in detail in Part 1 of this paper. The system comprises three models: Distributed Catchment Scale Model (DiCaSM), MODFLOW (v96 and v2000) and SWI. The DiCaSM simulates different components of the unsaturated zone water balance, including groundwater recharge. The recharge output from DiCaSM is used as input to the saturated zone model MODFLOW, which subsequently calculates groundwater flows and head distributions. The main objectives of this paper are: (1) to show the way more accurate predictions of groundwater levels in two Cyprus catchments can be obtained using improved estimates of groundwater recharge from the catchment water balance, and (2) to demonstrate the interface utility that simulates communication between unsaturated and saturated zone models and allows the transmission of data between the two models at the required spatial and temporal scales. The linked models can be used to predict the impact of future climate change on surface and groundwater resources and to estimate the future water supply shortfall in the island up to 2050. The DiCaSM unsaturated zone model was successfully calibrated and validated against stream flows with reasonable values for goodness of fit as shown by the Nash-Sutcliffe criterion. Groundwater recharge obtained from the successful tests was applied at various spatial and temporal scales to the Kouris and Akrotiri catchments in Cyprus. These recharge values produced good estimates of groundwater levels in both catchments. Once calibrated, the model was run using a number of possible future climate change scenarios. The results showed that by 2050, groundwater and surface water supplies would decrease by 35% and 24% for Kouris and 20% and 17% for Akrotiri, respectively. The gap between water supply and demand showed a linear increase with time. The results suggest that IHMS can be used as an effective tool for water authorities and decision makers to help balance demand and supply on the island. Copyright © 2010 John Wiley & Sons, Ltd. [source] Estimating the effectiveness of a rotational irrigation delivery system: A case study from Pakistan,IRRIGATION AND DRAINAGE, Issue 3 2010Noor ul Hassan Zardari warabandi; allocation de l'eau; bassin de l'Indus; Pakistan Abstract In this study, basic principles of the rotational irrigation water delivery system of Pakistan (i.e. the warabandi) and the performance of the warabandi system under current socio-economic conditions have been investigated from a farmers' survey completed from 154 farmers located on five watercourses of the lower Indus River Basin. It is shown that irrigation water allocation based on very limited criteria does not give much incentive to the farmers for improving agricultural income. Also, the survey results suggest that the productivity of limited irrigation water could not be maximized under the warabandi system. We have therefore suggested the basic principles of the warabandi system should be revised by making them suitable for the current socio-economic conditions. We propose that the existence or non-existence of fresh groundwater resources along with other critical variables should be taken into consideration when making canal water allocation decisions. A framework to allow distribution equity and efficiency in water allocations , such as considering the gross area of a tertiary canal, sensitivity of crop growth stage to water shortage, crop value, bias of allocation towards most water use efficient areas, the potential losses from water deficiency, etc. , should be developed as a tool to improve water productivity for Pakistan and for individual farmers. The contribution of groundwater in the farmers' income from agriculture and the economic value of irrigation water have also been estimated. Copyright © 2009 John Wiley & Sons, Ltd. Cette étude analyse les principes de base et la performance du tour d'eau (le warabandi) selon les conditions socio-économiques à partir d'une enquête auprès de 154 agriculteurs situés sur cinq cours d'eau du bassin inférieur de l'Indus. Il est montré que la répartition de l'eau d'irrigation basée sur peu de critères n'incite pas les agriculteurs à améliorer leurs revenus. En outre, les résultats de l'enquête suggèrent que la productivité de l'eau rare ne peut pas être améliorée dans le cadre du système warabandi. Nous avons donc proposé que les principes de base du warabandi soient révisés de façon à les adapter à la situation socio-économique actuelle. Nous proposons que la disponibilité en eaux souterraines ainsi que d'autres variables soient prises en compte dans les décisions d'allocation. Un cadre permettant une allocation de l'eau équitable et efficace , prenant en compte la surface brute commandée par un canal tertiaire, la sensibilité de la croissance des cultures au moment de la pénurie d'eau, la valeur de la récolte, l'orientation vers les zones valorisant le mieux l'eau, les pertes dues au déficit en eau, etc. , devrait être développé comme un outil pour améliorer la productivité de l'eau pour le Pakistan et pour les agriculteurs. La contribution des eaux souterraines au revenu des irrigants et la valeur économique de l'eau ont également été estimées. Copyright © 2009 John Wiley & Sons, Ltd. [source] Irrigation and drainage systems research and development in the 21st century,IRRIGATION AND DRAINAGE, Issue 4 2002Bart Schultz irrigation; drainage; développement durable; système de réseau Abstract One critical problem confronting mankind today is how to manage the intensifying competition for water between expanding urban centres, traditional agricultural activities and in-stream water uses dictated by environmental concerns. In the agricultural sector, the dwindling number of economically attractive sites for large-scale irrigation and drainage projects limits the prospects of increasing the gross cultivated area. Therefore, the required increase in agricultural production will necessarily rely largely on a more accurate estimation of crop water requirements on the one hand, and on major improvements in the construction, operation, management and performance of existing irrigation and drainage systems, on the other. The failings of present systems and the inability to sustainably exploit surface and groundwater resources can be attributed essentially to poor planning, design, system management and development. This is partly due to the inability of engineers, planners and managers to adequately quantify the effects of irrigation and drainage projects on water resources and to use these effects as guidelines for improving technology, design and management. To take full advantage of investments in agriculture, a major effort is required to modernize irrigation and drainage systems and to further develop appropriate management strategies compatible with the financial and socio-economic trends, and the environment. This calls for a holistic approach to irrigation and drainage management and monitoring so as to increase food production, conserve water, prevent soil salinization and waterlogging, and to protect the environment. All this requires, among others, enhanced research and a variety of tools such as water control and regulation equipment, remote sensing, geographic information systems, decision support systems and models, as well as field survey and evaluation techniques. To tackle this challenge, we need to focus on the following issues: affordability with respect to the application of new technologies; procedures for integrated planning and management of irrigation and drainage systems; analysis to identify causes and effects constraining irrigation and drainage system performance; evapotranspiration and related calculation methods; estimation of crop water requirements; technologies for the design, construction and modernization of irrigation and drainage systems; strategies to improve irrigation and drainage system efficiency; environmental impacts of irrigation and drainage and measures for creating and maintaining sustainability; institutional strengthening, proper financial assessment, capacity building, training and education. Copyright © 2002 John Wiley & Sons, Ltd. Résumé Aujourd'hui le problème critique pour l'humanité est comment manier la compétition intensifiante pour de l'eau entre les centres urbains en expansion, pour des activités traditionnellement agricoles et pour l'usage de l'eau fluviale prescrit par des conditions écologistes. Dans le secteur agricole les perspectives d'agrandir les champs cultivés bruts sont limitées par le nombre diminuant des terrains économiquement attractifs pour des projets d'irrigation et du drainage de grande envergure. Par conséquent l'augmentation nécessaire de la production agricole comptera surtout sur une évaluation plus précise du besoin des plantes d'un côté, et de l'autre sur de grandes améliorations dans la construction, dans l'opération, dans le management et dans la performance des systèmes d'irrigation et du drainage. On peut attribuer les défauts des systèmes actuels et l'incompétence d'exploiter durablement les ressources hydriques de surface et souterraines au planification, au système de la gestion de l'eau et au système du développement. Cela est partiellement dû à l'incapacité des ingénieurs, des planificateurs et des gérants, de quantifier adéquatement les effets des projets d'irrigation et de drainage sur les ressources hydriques et d'utiliser ces résultats pour améliorer la technologie, la planification et la gestion de l'eau. Pour profiter le mieux possible des investissements dans l'agriculture, on exige un effort considérable pour moderniser les systèmes d'irrigation et de drainage et pour développer des stratégies de gestion de l'eau qui doivent être appropriées et compatibles avec les tendances financières et socio-économiques et avec l'environnement. Ceci a besoin d'une procédure holistique pour la gestion et le monitorage de l'eau, pour augmenter la production d'aliments, pour conserver l'eau, pour prévenir la salination du sol et pour protéger l'environnement. Tout cela demande, entre autres choses, une recherche d'avant-garde et une variété d'instruments comme les contrôles du régime hydrique et les appareils de régulation, la télédétection, les systèmes de l'information géographique, les systèmes et les modèles de support de décision et de même les levés sur le terrain et les techniques d'évaluation. Pour entreprendre ce défi nous devons nous concentrer sur les questions suivantes: capacité de mettre enoeuvre des technologies nouvelles; le développement des procédures pour intégrer la planification et la gestion des systèmes d'irrigation et de drainage; l'analyse pour identifier les causes et les effets de forcer à la performance des systèmes d'irrigation et de drainage; l'évapotranspiration et les méthodes de calcul en question; l'évaluation des exigences hydriques des cultures; les technologies pour le dessein, la construction et la modernisation des projets d'irrigation et de drainage; les stratégies pour améliorer l'efficacité des systèmes d'irrigation et de drainage; les impacts des projets d'irrigation et de drainage et des mesures appropriées pour créer et entretenir la durabilité; l'amélioration du contexte institutionnel, l'évaluation financière, la formation et l'amélioration des compétences techniques. Copyright © 2002 John Wiley & Sons, Ltd. [source] Sustainable use of groundwater for irrigation: a numerical analysis of the subsoil water fluxes,IRRIGATION AND DRAINAGE, Issue 3 2002Mobin-ud-Din Ahmad irrigation; eaux souterraines; surexploitation de l'aquifère; recharge des eaux souterraines; utilisation nette de l'eau souterraine; modélisation au niveau de la parcelle cultivée; le Pakistan Abstract The food-producing regions of the world increasingly rely on irrigation from groundwater resources. Further increases of groundwater use can adversely affect the sustainability of irrigated agriculture and put food security at risk. Sustainability of irrigation at field scale with groundwater is obtained if groundwater recharge is in equilibrium with tubewell extractions and capillary rise. Traditional information on phreatic surface behaviour does not explain the processes causing a phreatic surface to decline or incline. In this study, the physically based numerical model Soil,Water,Atmosphere,Plant (SWAP) was applied to compute soil moisture content and vertical soil water fluxes in the unsaturated zone for the cotton,wheat and rice,wheat cropping system of Punjab, Pakistan. SWAP has been calibrated and verified with in situ measurements of soil moisture content and evapotranspiration fluxes measured by means of the Bowen ratio surface energy balance technique. Accurate data of the soil hydraulic properties are critical for the calibration of the soil moisture distribution. With knowledge of the van Genuchten,Mualem parameters available, SWAP could be applied to assess recharge and capillary rise for most field conditions, including basin irrigation. The results under Pakistani conditions show that deep percolation cannot always be estimated from root zone water balances. An annual recharge of 23.3 cm was computed for the cotton,wheat area. Sustainability of irrigation with groundwater is obtained if a reduction in irrigation with groundwater by 36% is obtained. An annual recharge of 38.9 cm is estimated in rice,wheat systems, and a reduction of 62% in groundwater extraction is required to reach sustainability of groundwater use at field scale. Such information cannot be obtained from classical phreatic surface fluctuation data, and unsaturated zone modelling therefore provides additional insights for groundwater policy making. Copyright © 2002 John Wiley & Sons, Ltd. RÉSUMÉ Les régions de production alimentaire de la planète se servent de plus en plus de l'eau souterraine pour l'irrigation. Ultérieurs accroissements de l'utilisation des eaux souterraines peuvent avoir des répercussions négatives sur l'irrigation agricole soutenable et sur la sécurité alimentaire. Une irrigation soutenable au niveau de la parcelle cultivée en utilisant l'eau souterraine est obtenue si le taux de recharge de cette dernière est en équilibre avec le taux d'extraction des puits et la remontée capillaire. L'information traditionellement disponible concernant l'évolution du niveau phréatique ne permet pas d'expliquer les procès qui causeraient son abaissement ou son accroissement. Cette étude présente les resultats obtenus grâce à l'utilisation d'un modèle numérique appelé Soil,Water,Atmosphere,Plant (SWAP), qui se base sur des principes physiques, avec lequel ont été calculés les taux d'humidité du sol et les flux verticaux d'humidité dans la zone non-saturée du sol pour ce qui concèrne le système de cultivation coton,blé et riz,blé du Pounjab, au Pakistan. SWAP a été calibré et verifié grâce à des mesures in situ du taux d'humidité du sol et des flux d'évapotranspiration quantifiés en appliquant le rapport de Bowen, basé sur le concept du bilan énergétique au niveau du sol. Disposer de données prises concernant les propriétés hydrauliques du sol est essentiel pour calibrer la distribution de l'humidité du sol. Grâce à la connaissance des paramètres de van Genuchten,Mualem disponibles, SWAP a pu être utilisé pour évaluer le taux de recharge et la remontée capillaire en fonction de différentes conditions du terrain, irrigation de bassin incluse. Les résultats sous les conditions Pakistanes montrent que la percolation profonde ne peut pas toujours être estimée par les équilibres hydrologiques de la zone radicale. Une recharge annuelle de 23,3 cm a été estimée pour la zone coton,blé. L'utilisation soutenable de l'eau souterraine pour l'irrigation serait obtenue si on en réduisait l'extraction de 36%. Pour ce qui concerne la zone riz,blé, une recharge annuelle de 38,9 cm a été estimée, et une réduction de 62% de l'extraction de l'eau souterraine serait nécessaire pour une utilisation soutenable de l'eau souterraine à l'échelle de la parcelle cultivée. Ces informations ne peuvent pas être obtenues sur la base des données ordinaires concernant les fluctuations du niveau phréatique; la modélisation représente donc un appui essentiel en matière de prise de décision concernant la gestion de l'eau souterraine. Copyright © 2002 John Wiley & Sons, Ltd. [source] Non,Market Interventions in Water,Sharing:Case Studies from West Bengal, IndiaJOURNAL OF AGRARIAN CHANGE, Issue 4 2002Vikas Rawal This paper deals with two issues that are important areas of concern in the recent literature on water management in less,developed countries: forms of ownership of groundwater resources and alternatives to anarchy in the exploitation and use of groundwater. The emergence of a market for irrigation water has been argued to have the potential to provide irrigation water to large numbers of small cultivators in developing countries. The development of free markets for water, however, has also been shown to be associated with the emergence of ,water,lords' and with contracts for the purchase and sale of water that are biased against the poor. By contrast, this paper presents two examples of viable non,market interventions in water,sharing , regulation of water markets by village councils and cooperative tubewell groups , from villages in West Bengal, India. These interventions both improved the efficiency of water,use and represented relatively equitable arrangements for water,sharing. [source] Current Issues in the Economics of Groundwater Resource ManagementJOURNAL OF ECONOMIC SURVEYS, Issue 5 2004Phoebe Koundouri Abstract., The issue of groundwater management remains a practical concern in many regions throughout the world, while water managers continue to grapple with the question of how to manage this resource. In this article, we attempt to bring the most advanced and appropriate tools to bear on the issue of resource allocation involving groundwater. Our objective is to demonstrate the state of the art in the literature on ways to think about this complex resource and to deal with the important economic issues emanating from its complexity. We present the conceptual framework within which economists examine the elements interacting in the management of groundwater resources, indicate why the role of the market is limited with respect to the price of this very complex resource, and point to the mechanisms that can pull competitive groundwater price and quality-graded quantity of groundwater in line with their equilibrium levels. In particular, we critically review economic models of groundwater use, examine the potential for groundwater management, discuss the difficulties encountered in the estimation of the relevant control variables of such models, and identify the advantages and limitations of the instruments devised for the efficient use (allocation) of this resource. Finally, we argue that devised regulatory schemes usually ignore the information and knowledge needed for their implementation, and we suggest a core of conditions necessary for successful groundwater management reforms. [source] Valuing groundwater recharge through agricultural production in the Hadejia-Nguru wetlands in northern NigeriaAGRICULTURAL ECONOMICS, Issue 3 2000Gayatri Acharya Production function approach; Valuation; Wetlands; Groundwater recharge; Ecosystem function Abstract This study applies a production function approach to value the groundwater recharge function of the Hadejia-Nguru wetlands in northern Nigeria. The groundwater recharge function supports dry season agricultural production which is dependent on groundwater abstraction for irrigation. Using survey data this paper first carries out an economic valuation of agricultural production, per hectare of irrigated land. We then value the recharge function as an environmental input into the dry season agricultural production and derive appropriate welfare change measures. Welfare change is calculated using the estimated production functions and hypothetical changes in groundwater recharge and hence, groundwater levels. By focusing on agricultural production dependent solely on groundwater resources from the shallow aquifer, this study establishes that the groundwater recharge function of the wetlands is of significant importance for the floodplain. [source] |