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Water Scarcity (water + scarcity)
Selected AbstractsECONOMIC TRENDS: EGYPT: Water ScarcityAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 7 2010Article first published online: 1 SEP 2010 No abstract is available for this article. [source] Addressing China's Water Scarcity: recommendations for selected water resource management issues , By Jian Xie with Andres Lieberthal et al.ASIAN-PACIFIC ECONOMIC LITERATURE, Issue 2 2009R. Quentin Grafton No abstract is available for this article. [source] Infiltration into effluent irrigation-induced repellent soils and the dependence of repellency on ambient relative humidityHYDROLOGICAL PROCESSES, Issue 17 2007R. Wallach Abstract As a result of water scarcity and as a means of wastewater disposal, reuse of treated sewage effluent in irrigated agriculture is practiced worldwide. Among the detrimental aspects of wastewater re-use in agriculture is the possibility that soils will be rendered water repellent. The current study focuses on time dependent variation of infiltration rate in effluent-induced repellent soils, and time dependent variation in water repellency at different levels of ambient relative humidity (RH). The shape of the cumulative infiltration curve of water was found to depend on the repellency degree (concave for wettable and slightly repellent soils, convex for severely repellent soil). Compared with infiltration rates in the wettable and slightly repellent soils, infiltration rates in the severely repellent soil were very low at the beginning and then increased. When the liquid-vapor surface tension was reduced by means of ethanol addition to the infiltrating solution, the cumulative infiltration curve of the severely repellent soil also became concave. Repellency degree (as measured by WDPT) was found to be essentially constant over a large range of ambient RH values (<10 , ,81%), and to increase sharply at values above 90%. The relative increase in water drop penetration time (WDPT) at high RH was greatest for the least repellent soil (10-fold increase in WDPT), and least for the most repellent soil (2-fold increase in WDPT). At RH > 90%, the time to reach equilibrium with respect to WDPT and soil moisture content was similar. In contrast, at values of ambient RH ranging from < 10 to 81%, WDPT was invariant over the course of reaching equilibrium with respect to moisture content. However, after reaching moisture content equilibrium, WDPT declined with increasing time. Copyright © 2007 John Wiley & Sons, Ltd. [source] A decision support tool for irrigation infrastructure investments,IRRIGATION AND DRAINAGE, Issue 4 2010Shahbaz Khan outil d'aide à la décision; gestion de l'eau; investissements saisonniers et à long terme; optimisation; simulation; analyse coûts-avantages; ensemble de l'exploitation; négociation de l'eau; économie d'eau Abstract Increasing water scarcity, climate change and pressure to provide water for environmental flows urge irrigators to be more efficient. In Australia, ongoing water reforms and most recently the National Water Security Plan offer incentives to irrigators to adjust their farming practices by adopting water-saving irrigation infrastructures to match soil, crop and climatic conditions. WaterWorks is a decision support tool to facilitate irrigators to make long- and short-term irrigation infrastructure investment decisions at the farm level. It helps irrigators to improve the economic efficiency, water use efficiency and environmental performance of their farm businesses. WaterWorks has been tested, validated and accepted by the irrigation community and researchers in NSW, Australia. The interface of WaterWorks is user-friendly and flexible. The simulation and optimisation module in WaterWorks provides an opportunity to evaluate infrastructure investment decisions to suit their seasonal or long-term water availability. The sensitivity analysis allows substantiation of the impact of major variables. Net present value, internal rate of return, benefit,cost ratio and payback period are used to analyse the costs and benefits of modern irrigation technology. Application of WaterWorks using a whole farm-level case study indicates its effectiveness in making long- and short-term investment decisions. WaterWorks can be easily integrated into commercial software such as spreadsheets, GIS, real-time data acquisition and control systems to further enhance its usability. WaterWorks can also be used in regional development planning. Copyright © 2009 John Wiley & Sons, Ltd. L'augmentation de la rareté de l'eau, le changement climatique et la pression pour fournir de l'eau pour l'environnement incitent les irrigants à être plus efficaces. En Australie les réformes en cours sur l'eau, et plus récemment le Plan National de Sécurité de l'Eau, incitent les irrigants à ajuster leurs pratiques agricoles par l'adoption d'infrastructures d'irrigation économisant l'eau pour s'adapter aux conditions de sols, de cultures et de climat. WaterWorks est un outil d'aide à la décision pour faciliter les décisions d'investissement à long terme et court terme au niveau de l'exploitation. Il aide les irrigants à améliorer l'efficacité économique, l'efficacité de l'utilisation de l'eau et la performance environnementale de leurs exploitations agricoles. Le WaterWorks a été testé, validé et accepté par la communauté de l'irrigation dans le New South Wales, Australie. L'interface de WaterWorks est convivial et flexible. Le module de simulation et d'optimisation dans WaterWorks permet d'évaluer les décisions d'investissement en fonction de la disponibilité en eau saisonnière ou à long terme. L'analyse de sensibilité permet d'étayer l'impact des principales variables. La valeur actuelle nette, le taux de rendement interne, le ratio coûts-avantages et la période de récupération sont utilisés pour analyser les coûts et les avantages des technologies modernes d'irrigation. L'application de WaterWorks à une étude de cas complète au niveau de l'exploitation montre son efficacité pour les décisions d'investissement à long terme et court terme. Le WaterWorks peut être facilement intégré dans des logiciels commerciaux tels que les tableurs, les SIG, des systèmes d'acquisition de données en temps réel et de contrôle afin d'améliorer sa convivialité. Le WaterWorks peut également être utilisé pour la planification du développement régional. Copyright © 2009 John Wiley & Sons, Ltd. [source] Addressing the unanswered questions in global water policy: a methodology framework,IRRIGATION AND DRAINAGE, Issue 1 2003Charlotte de Fraiture Demande et fourniture de l'eau et de la nourriture au niveau globale 1995,2025; modélisation globale; politique globale sur l'eau; projections 2025 Abstract Are the available water resources sufficient to produce food for the growing world population while at the same time meet increasing municipal, industrial and environmental requirements? Projections for the year 2025, presented by different research groups at the second World Water Forum in The Hague, show an increase in global agricultural water use ranging from 4 to 17%. Estimates for the growth of total withdrawals, including domestic and industrial sectors, vary from 22 to 32%. This range is the result of differences in model structure and assumptions. Although these analyses were instrumental in raising awareness concerning the extent of present and future water scarcity problems, they raise many questions, which remain largely unanswered. The questions relate to the impact of water- and food-related policies on global and regional water scarcity, food production, environment and livelihoods through the year 2025. The International Food Policy Research Institute (IFPRI) and the International Water Management Institute (IWMI) embarked on a joint modeling exercise to address these questions. This paper lays out the issues and discusses the methodology. During the 18th ICID Congress in July 2002 at Montreal, preliminary results will be presented. Copyright © 2003 John Wiley & Sons, Ltd. RÉSUMÉ Est-ce que les ressources en eau disponible sont suffisantes pour produire la nourriture pour une population mondiale qui s'accroît, et satisfaire en même temps les besoins municipaux, industriels et environnementaux? Les projections faites pour l'an 2025 par différents groupes de chercheurs lors du 2ème Forum Mondial de l'Eau à la Haye montrent une augmentation de 4 à 17% dans l'utilisation globale de l'eau agricole. Les estimations pour l'augmentation des prélèvements, y compris les secteurs domestiques et industriels, varient de 22 à 32%. Cette portée est le résultat des différences dans la structure des modèles. Quoique ces analyses permettent de sensibiliser le peuple sur les problèmes actuels et futurs de la disponibilité de l'eau, elles soulèvent de nombreuses questions qui restent non-résolues en bonne part. Ces questions concernent l'impact aux niveaux régionau et globau des politiques sur l'eau et la nourriture, la production alimentaire, l'environnement et les moyens d'existence et sources de revenu vers l'an 2025. L'Institut International de Recherche sur la Politique Alimentaire (IFPRI) et l'Institut International de Gestion d'Eau (IWMI) préparent conjointement un modèle pour traiter toutes ces questions non-résolues. Le rapport en question identifie toutes ces questions et discute la méthodologie. Au 18ème Congrès de Montréal en juillet 2002, les résultats préliminaires seront présentés. Copyright © 2003 John Wiley & Sons, Ltd. [source] Exogenous Glycinebetaine and Salicylic Acid Application Improves Water Relations, Allometry and Quality of Hybrid Sunflower under Water Deficit ConditionsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2009M. Hussain Abstract Limited water availability hampers the sustainability of crop production. Exogenous application of glycinebetaine (GB) and salicylic acid (SA) has been found very effective in reducing the adverse effects of water scarcity. This study was conducted to examine the possible role of exogenous GB and SA application in improving the growth and water relations of hybrid sunflower (Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation, viz. control (normal irrigations), water stress at budding stage (irrigation missing at budding stage) and water stress at flowering stage (FS) (irrigation missing at FS). GB and SA were applied exogenously at 100 and 0.724 mm respectively, each at the budding and FS. Control plants did not receive application of GB and SA. Water stress reduced the leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), leaf relative water contents, water potential, osmotic potential, turgor pressure, achene yield and water use efficiency. Nevertheless, exogenous GB and SA application appreciably improved these attributes under water stress. However, exogenous GB application at the FS was more effective than other treatments. Net assimilation rate was not affected by water stress as well as application of GB and SA. The protein contents were considerably increased by water stress at different growth stages, but were reduced by exogenous GB and SA application. The effects of water stress and foliar application of GB were more pronounced when applied at FS than at the budding stage. Moreover, exogenous GB application was only advantageous under stress conditions. [source] Spot water markets and risk in water supplyAGRICULTURAL ECONOMICS, Issue 2 2005Javier Calatrava Water markets; Economic risk; Water availability; Irrigated agriculture Abstract Water availability patterns in semiarid regions are typically extremely variable. Even in basins with a highly developed infrastructure, users are subject to unreliable water supplies, incurring substantial economic losses during periods of scarcity. More flexible instruments, such as voluntary exchanges of water among users, can help users to reduce risk exposure. This article looks at the effects of spot water markets on the economic risk caused by water availability variations. Our theoretical and empirical risk analyses are based on the random profits of water users. Profit probability density functions are formally and graphically characterized for both water sellers and buyers under several possible market outcomes. We conclude from this analysis that, where water supply is stochastic, water markets unambiguously reduce both parties' risk exposure. The empirical study is conducted on an irrigation district in the Guadalquivir Valley (Southern Spain), where there is a high probability of periods of extreme water scarcity. Water demand functions for the district representative irrigators and a spatial equilibrium model are used to simulate market exchanges and equilibrium. This programming model is combined with statistical simulation techniques. We show that the profit probability distribution of a representative irrigator is modified if water exchanges are authorized, leading to risk reductions. Results also indicate that if the market were extended to several districts and users that are subject to varying hydrological risk exposure, extremely low-profit events would be less likely to occur. In sum, we show that exchanging water in annual spot markets can reduce farmers' economic vulnerability caused by water supply variability across irrigation seasons. These results support the water policy reform carried out in Spain in 1999 to allow for voluntary water exchanges among right holders. [source] Models, Assumptions, and Stakeholders: Planning for Water Supply Variability in the Colorado River Basin,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2008Dustin Garrick Abstract:, Declining reservoir storage has raised the specter of the first water shortage on the Lower Colorado River since the completion of Glen Canyon and Hoover Dams. This focusing event spurred modeling efforts to frame alternatives for managing the reservoir system during prolonged droughts. This paper addresses the management challenges that arise when using modeling tools to manage water scarcity under variable hydroclimatology, shifting use patterns, and institutional complexity. Assumptions specified in modeling simulations are an integral feature of public processes. The policymaking and management implications of assumptions are examined by analyzing four interacting sources of physical and institutional uncertainty: inflow (runoff), depletion (water use), operating rules, and initial reservoir conditions. A review of planning documents and model reports generated during two recent processes to plan for surplus and shortage in the Colorado River demonstrates that modeling tools become useful to stakeholders by clarifying the impacts of modeling assumptions at several temporal and spatial scales. A high reservoir storage-to-runoff ratio elevates the importance of assumptions regarding initial reservoir conditions over the three-year outlook used to assess the likelihood of reaching surplus and shortage triggers. An ensemble of initial condition predictions can provide more robust initial conditions estimates. This paper concludes that water managers require model outputs that encompass a full range of future potential outcomes, including best and worst cases. Further research into methods of representing and communicating about hydrologic and institutional uncertainty in model outputs will help water managers and other stakeholders to assess tradeoffs when planning for water supply variability. [source] EFFECTS OF INCREASED DELTA EXPORTS ON SACRAMENTO VALLEY'S ECONOMY AND WATER MANAGEMENT,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2003Stacy K. Tanaka ABSTRACT: Exports from the Sacramento-San Joaquin Delta are an important source of water for Central Valley and Southern California users. The purpose of this paper is to estimate and analyze the effects increased exports to south of Delta users would have on the Sacramento Valley economy and water management if water were managed and reallocated for purely economic benefits, as if there were an ideal Sacramento Valley water market. Current Delta exports of 6,190 thousand acre-feet per year were increased incrementally to maximum export pumping plant capacities. Initial increases in Delta exports did not increase regional water scarcity, but decreased surplus Delta flows. Further export increases raised agricultural scarcity. Urban users suffer increased scarcity only for exports exceeding 10,393 taf/yr. Expanding exports raises the economic value of expanding key facilities (such as Engle bright Lake and South Folsom Canal) and the opportunity costs of environmental requirements. The study illustrates the physical and economic capacity of the Sacramento Valley to further increase exports of water to drier parts of the state, even within significant environmental flow restrictions. More generally, the results illustrate the physical capacity for greater economic benefits and flexibility in water management within environmental constraints, given institutional capability to reoperate or reallocate water resources, as implied by water markets. [source] Assessing sediment inputs to small reservoirs in Upper East Region, GhanaLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 4 2009Afua Adwubi Abstract Many small dams and dugouts have been constructed in the Upper East Region of Ghana to address the problem of regional water scarcity. The reservoirs were constructed primarily as water supplies for agricultural irrigation and livestock watering, aquaculture and domestic use. However, many of the reservoirs dry up during the dry season, affecting the livelihoods of their basin inhabitants. A major cause for the dried reservoirs is siltation, which reduces the reservoir's storage capacities. The goal of this study is to quantify the annual siltation rate of four study reservoirs, using a bathymetric survey and reservoir soil sampling. The sediment yield and its relation to catchment area also were assessed. The results of this study indicate that the annual siltation rates are 1272, 3518, 2764 and 6135 t year,1 for Doba, Dua, Zebilla and Kumpalgogo reservoirs, respectively. Analyses of the sediment yield and catchment areas illustrated that the sediment yields decreased with increasing catchment area. All the study reservoirs have lost their dead storage capacity, which was meant to store sediment until the end of their anticipated design lives. The decreasing storage capacity because of siltation will affect the livelihoods of the local basin inhabitants, as the reservoirs will not be able to achieve all their intended purposes. The results of this study indicate that, because siltation is not the only factor threatening the benefits gained from the reservoirs, the integrated assessment of all relevant factors is required. [source] Water use (and abuse) and its effects on the crater-lakes of Valle de Santiago, MexicoLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2000Javier Alcocer Abstract Most Mexicans live in the arid and semiarid regions that represent two-thirds of the Mexican territory, where water is scarce. Natural, as well as human, causes are favouring the degradation of Mexican lakes. There is a clear need to develop and implement sustainable water-use programmes at a catchment scale. However, the accelerated degradation rate of the Mexican lakes means that there will not be enough time to perform whole-basin evaluations to establish sustainable water-use programmes before the lakes dry up. The case of the Valle de Santiago crater-lakes clearly illustrates the declining trend that Mexican inland aquatic resources follow. Vegetation clearance, overgrazing, abatement of phreatic waters and salinization have induced severe erosion and overall desertification (land degradation) in the basin for what, it seems, a long time (i.e. prehispanic times). In this way, human activities could be provoking at least the following negative consequences: a hotter and drier local climate, water scarcity, dust storms and soil salinization. The aquatic (surface and groundwater) resources of the Valle de Santiago basin have been seriously threatened. Two of the four crater-lakes have already dried up and phreatic mantle abatement reaches up to 2.5 m per year. In spite of these facts, no sustainable water-use programme has been established yet. The future scenery of this Mexican basin looks alarmingly like many other basins in the central and northern Mexican territories. [source] Overcoming growing water scarcity: Exploring potential improvements in water productivity in IndiaNATURAL RESOURCES FORUM, Issue 3 2010Upali A. Amarasinghe Abstract Improvements in water productivity (WP) are often suggested as one of the alternative strategies for overcoming growing water scarcity in India. This paper explores the potential improvements in WP of food grains at district level, which currently varies between 0.11 and 1.01 kilogram per cubic metre (kg/m3), in the 403 districts that account for 98% of the total production of food grains. The paper first finds the maximum yield function conditional on consumptive water use (CWU) and then explores the potential improvements in WP by: (a) bridging the gap between actual and maximum yield while keeping CWU constant; and (b) changing the maximum yield by adjusting the CWU using supplementary or deficit irrigation. Deficit irrigation in some areas may decrease yield but can increase production if land availability is not a constraint. A large potential exists for bridging the yield gap in irrigated areas with CWU between 300 and 475 mm. Of the 222 districts that fall under this category, a 50% reduction in yield gap alone could increase production by 100 million tonnes (Mt) without increasing CWU. Supplementary irrigation can increase yield and WP in rain-fed and irrigated areas of 266 and 16 districts with CWU is below 300 mm. Deficit irrigation in irrigated areas of 185 districts with CWU above 475 mm could increase yield, WP and production. Decreasing CWU in irrigated areas with CWU between 425 and 475 mm reduces yield slightly, but if availability of land is not a constraint then the benefits due to water saving and production increases could exceed the cost. [source] Investments in agricultural water management for poverty reduction in Africa: Case studies of Limpopo, Nile, and Volta river basinsNATURAL RESOURCES FORUM, Issue 3 2008Munir A. Hanjra Abstract Much of Sub-Saharan Africa is burdened with water scarcity and poverty. Continentally, less than four percent of Africa's renewable water resources are withdrawn for agriculture and other uses. Investments in agricultural water management can contribute in several ways to achieving the Millennium Development Goals of eradicating extreme poverty and hunger and ensuring environmental sustainability. Increased yield and cropping area and shifts to higher valued crops could help boost the income of rural households, generate more employment, and lower consumer food prices. These investments can also stabilize output, income and employment, and have favourable impacts on education, nutrition and health, and social equity. Investments in agricultural water management can cut poverty by uplifting the entitlements and transforming the opportunity structure for the poor. The overall role of investments in agricultural water management in eradicating hunger and poverty is analyzed. This paper contributes to the present debate and efforts to identify strategies and interventions that can effectively contribute to poverty reduction in Africa. It provides an overview of population growth, malnutrition, income distribution and poverty for countries in three case study river basins , Limpopo, Nile, and Volta. With discussions on the contribution of agriculture to national income and employment generation, the paper explores the linkages among water resources investments, agricultural growth, employment, and poverty alleviation. It examines the potential for expansion in irrigation for vertical and horizontal growth in agricultural productivity, via gains in yield and cropping area to boost the agricultural output. Factors constraining such potential, in terms of scarcity and degradation of land and water resources, and poor governance and weak institutions, are also outlined. The paper argues that increased investments in land and water resources and related rural infrastructure are a key pathway to enhance agricultural productivity and to catalyze agricultural and economic growth for effective poverty alleviation. [source] Water rights and legal pluralism: four contexts for negotiationNATURAL RESOURCES FORUM, Issue 1 2001Bryan Randolph Bruns Abstract Increasing water scarcity is increasing pressure on water management institutions, particularly in the area of water rights. A common response is to formalise water tenure, one of several options for securing access and resolving conflicts concerning water allocation. This article looks at four contexts where negotiation, self-governance and concepts of legal pluralism may help improve water resource management. Existing users and potential new users need to negotiate before water resources are developed. Users can participate in forums with authority to solve basin management problems through self-governance. Negotiated water transfers offer an alternative to water acquisition by expropriation. [source] Rethinking the management of transboundary freshwater resources: a critical examination of modern international law and practiceNATURAL RESOURCES FORUM, Issue 1 2000Jeffrey AlbertArticle first published online: 9 OCT 200 Abstract Available freshwater stocks are being depleted and impaired on a widespread basis, with acute shortages an increasingly frequent condition in arid climates. In transboundary basins, water scarcity and pollution compound interstate tension and contribute to human suffering and ecological damage. This article provides theoretical perspectives on shared freshwater disputes and on the evolution of the international law of shared water resources. It argues that the UN Convention on the Non-Navigational Uses of International Watercourses (ratified by some countries, but not yet in force) is inadequate as a framework convention in terms of providing general obligations on the future parties or an institutional framework for future action. The paper suggests that three critical concepts be considered in future management of shared water resources: (1) the unitary character of watersheds (where the absence of extra-basin diversions allows); (2) joint or "communitarian" watershed management; and (3) the relevance of international trade to alleviating regional food stress, resulting from local water scarcity. Finally, it proposes the establishment of an international advisory body on shared water disputes, modelled after the Intergovernmental Panel on Climate Change (IPCC), whose role is codified in the Kyoto Protocol to the United Nations Framework Convention on Climate Change. [source] Behavioral adaptations to heat stress and water scarcity in white-faced capuchins (Cebus capucinus) in Santa Rosa National Park, Costa RicaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Fernando A. Campos Abstract We examined thermoregulatory behaviors in a wild population of white-faced capuchins (Cebus capucinus) inhabiting a highly seasonal dry forest in Santa Rosa National Park (SRNP), Costa Rica. The dry season in SRNP lasts ,5 months and is characterized by high ambient temperatures regularly exceeding 37°C, low relative humidity, and the near absence of precipitation. This study demonstrates that capuchins rest more and travel shorter distances during the hottest and driest hours of the day, and suggests that they extend their tongues to lower body temperature via evaporative cooling. Seasonal weather patterns and group movement data reported here are based on 940 h of observations on three social groups of capuchins (wet season: 370 h, dry season: 570 h). In the dry season, the proportion of time spent resting increased at higher temperatures whereas the proportion of time spent traveling decreased. Distance traveled between location points taken at half-hour intervals decreased significantly as temperature increased, although the correlation was not strong. Capuchins exposed their tongues during hot, dry, windy conditions, and this behavior was much more frequent in the dry season. Temperature was significantly higher and humidity significantly lower for "tongue-out" events than expected for a random event in the dry season. Finally, as surface water became scarce, home-range areas of heavy use became increasingly centered on the remaining permanent water sources. These results suggest that heat stress and water scarcity are significant influences on the behavior of capuchins in hot, dry conditions. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] The problems of sustainable water use in the Mediterranean and research requirements for agricultureANNALS OF APPLIED BIOLOGY, Issue 3 2004J LARAUS Summary This study addresses the sustainable use of water resources in the Mediterranean basin, particularly in the Southern and Eastern parts of the region, and the many problems generated by water scarcity and misuse. Water economy in the region is beset by two specific problems: high irrigation needs and changes in consumer demands (especially after population shifts from rural to urban areas and because of increasing tourism and industrialisation). The challenges presented by the water crisis are even greater because of growing populations and estimated future climatic changes in the region. The integrated management of limited water resources in the Southern and Eastern parts of the Mediterranean involves several areas of research. Those most directly related with agriculture concern improving water (and nutrient) use in agriculture through the management and breeding of irrigated and rain-fed crops. However, these fields of research address only one face of a multi-factorial equation that affects water sustainability in the region. Thus, other research fields include the design of comprehensive water policies and integrated planning, and technologies for advanced water treatment and re-use. Moreover, local problems and socio-economic aspects must be considered when addressing research issues. [source] Urban water management: optimal price and investment policy under climate variability,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2009Neal Hughes Australian urban water utilities face a significant challenge in designing appropriate demand management and supply augmentation policies in the presence of significant water scarcity and climate variability. This article considers the design of optimal demand management and supply augmentation policies for urban water. In particular, scarcity pricing is considered as a potential alternative to the predominant demand management policy of water restrictions. A stochastic dynamic programming model of an urban water market is developed based on data from the ACT region. Given a specification of the demand and supply for urban water state dependent optimal price and investment policies are estimated. The results illustrate how the optimal urban water price varies inversely with the prevailing storage level and how the optimal timing of investment differs significantly between rain dependent and rain independent augmentation options. [source] Market-Based Policy Instruments, Irrigation Water Demand, and Crop Diversification in the Bow River Basin of Southern AlbertaCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2010Lixia He This paper investigates two market-based policy instruments, short-term water trading and volumetric water pricing, in a jurisdiction where historical water allocations are based on the seniority of appropriative water rights. The analysis identifies the potential effects of alternative surface water allocations on crop choices and on producer incomes in three irrigation districts in the Bow River Sub-basin of the South Saskatchewan River. The short-run effects of these alternative policy instruments are examined in scenarios where seasonal water supplies are reduced by 10,30% relative to the 2003 water usage levels. An important contribution of the paper is to present a computational, positive mathematical programming model that integrates both irrigation decisions and specific crop choices when characterizing agents' optimal responses to moderate water scarcity. The numerical results illustrate the manner in which the use of these market-based economic instruments can increase the irrigated land area and economic welfare relative to the allocations made based only on the seniority of water rights. Under full information with no transactions costs, the use of water pricing for allocation purposes can achieve the same production outcomes as could be reached under short-term water trading. However, the distribution of potential monetary gains and losses among agents would vary considerably across policies. Le présent article étudie deux instruments de politique fondés sur le marché, soit le commerce de l'eau à court terme et l'établissement du prix de l'eau en fonction du volume, dans une province où l'attribution de l'eau est historiquement fondée sur l'ancienneté des droits d'appropriation de l'eau. L'analyse a exposé les effets potentiels de divers moyens d'attribution de l'eau de surface sur le choix des cultures et le revenu des producteurs dans trois districts d'irrigation situés dans le sous-bassin de la rivière Bow qui s'écoule dans le sous-bassin de la rivière Saskatchewan Sud. Nous avons examiné les effets à court terme de ces moyens dans des scénarios où les approvisionnements saisonniers en eau ont été réduits de 10 à 30 p. 100 par rapport aux niveaux d'utilisation de l'eau établis en 2003. Le présent article visait, entre autres, à présenter un modèle de programmation mathématique positive intégrant à la fois les décisions concernant l'irrigation et le choix de cultures spécifiques au moment de caractériser les réactions optimales des agents face à une rareté modérée de l'eau. Les résultats numériques ont montré de quelle façon l'utilisation de ces instruments économiques fondés sur le marché pouvait accroître les superficies irriguées et le bien-être économique comparativement à l'attribution de l'eau fondée sur l'ancienneté des droits d'appropriation de l'eau. Selon les renseignements complets sans coûts de transaction, le recours à l'établissement du prix de l'eau en fonction du volume et le commerce de l'eau à court terme peuvent permettre d'obtenir les mêmes résultats en matière de production. Toutefois, la répartition des pertes et des gains éventuels entre les agents varieraient considérablement d'une politique à l'autre. [source] | |||||||||||||||||||