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Water Demand (water + demand)

Distribution by Scientific Domains
Engineering40%
Business, Economics, Finance and Accounting25%
Earth and Environmental Science11%
Chemistry11%
Life Sciences7%

Selected Abstracts

Market-Based Policy Instruments, Irrigation Water Demand, and Crop Diversification in the Bow River Basin of Southern Alberta

CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2010
Lixia 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]

Reduction of the Water Demand in the Process Industry by Production-Integrated Application of the Catalytic Electrolysis,

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2004
M. Forstmeier
In many process industry applications fresh water demand can be reduced significantly by production-integrated electrolytic disinfection of the process water. This contribution deals with the basic principles of electrolytic water disinfection and presents two case studies: application of the proposed method during the production of liquid detergents and during a metallurgical production process. [source]

Water, Adaptation, and Property Rights on the Snake and Klamath Rivers,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2007
Richard A. Slaughter
Abstract:, Water demand in a viable economy tends to be dynamic: it changes over time in response to growth, drought, and social policy. Institutional capacity to re-allocate water between users and uses under stress from multiple sources is a key concern. Climate change threatens to add to those stresses in snowmelt systems by changing the timing of runoff and possibly increasing the severity and duration of drought. This article examines Snake and Klamath River institutions for their ability to resolve conflict induced by demand growth, drought, and environmental constraints on water use. The study finds that private ownership of water rights has been a major positive factor in successful adaptation, by providing the basis for water marketing and by promoting the use of negotiation and markets rather than politics to resolve water conflict. [source]

Local hydrologic effects of introducing non-native vegetation in a tropical catchment

ECOHYDROLOGY, Issue 1 2008
Maite Guardiola-Claramonte
Abstract This study investigates the hydrologic implications of land use conversion from native vegetation to rubber (Hevea brasiliensis) in Southeast Asia. The experimental catchment, Nam Ken (69 km2), is located in Xishuangbanna Prefecture (22°N, 101°E), in the south of Yunnan province, in southwestern China. During 2005 and 2006, we collected hourly records of 2 m deep soil moisture profiles in rubber and three native land-covers (tea, secondary forest and grassland), and measured surface radiation above the tea and rubber canopies. Observations show that root water uptake of rubber during the dry season is controlled by day-length, whereas water demand of the native vegetation starts with the arrival of the first monsoon rainfall. The different dynamics of root water uptake in rubber result in distinct depletion of soil moisture in deeper layers. Traditional evapotranspiration and soil moisture models are unable to simulate this specific behaviour. Therefore, a different conceptual model, taking in account vegetation dynamics, is needed to predict hydrologic changes due to land use conversion in the area. Copyright © 2008 John Wiley & Sons, Ltd. [source]

An operational algorithm for residential cogeneration systems based on the monitored daily-basis energy demand

ELECTRICAL ENGINEERING IN JAPAN, Issue 2 2010
Yuka Yamagishi
Abstract Residential cogeneration systems with PEFC are promising as distributed power system resources with the ability to improve energy system efficiency. However, it is important to develop an efficient algorithm for operation because the energy demand at each house differs greatly from day to day. In this paper, we propose an operational algorithm and evaluate it from the viewpoint of energy conservation and economic effectiveness based on the energy demand characteristics. In the algorithm, the hot water and electricity demand on the next day are estimated based on the average of past data. The results of simulations using actually monitored energy demand data indicate that (1) the greater the electrical demand of a household, the more effective this algorithm becomes with respect to energy conservation; (2) the greater the hot water demand of a household, the more effective this algorithm becomes with respect to economic effectiveness. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(2): 37,45, 2010; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/eej.20892 [source]

Regional water resource implications of bioethanol production in the Southeastern United States

GLOBAL CHANGE BIOLOGY, Issue 9 2009
JASON M. EVANS
Abstract The Energy Independence and Security Act (EISA) of 2007 mandates US production of 136 billion L of biofuel by 2022. This target implies an appropriation of regional primary production for dedicated feedstocks at scales that may dramatically affect water supply, exacerbate existing water quality challenges, and force undesirable environmental resource trade offs. Using a comparative life cycle approach, we assess energy balances and water resource implications for four dedicated ethanol feedstocks , corn, sugarcane, sweet sorghum, and southern pine , in two southeastern states, Florida and Georgia, which are a presumed epicenter for future biofuel production. Net energy benefit ratios for ethanol and coproducts range were 1.26 for corn, 1.94 for sweet sorghum, 2.51 for sugarcane, and 2.97 for southern pine. Corn also has high nitrogen (N) and water demand (11.2 kg GJnet,1 and 188 m3 GJnet,1, respectively) compared with other feedstocks, making it a poor choice for regional ethanol production. Southern pine, in contrast, has relatively low N demand (0.4 kg GJnet,1) and negligible irrigation needs. However, it has comparatively low gross productivity, which results in large land area per unit ethanol production (208 m2 GJnet,1), and, by association, substantial indirect and incremental water use (51 m3 GJnet,1). Ultimately, all four feedstocks require substantial land (10.1, 3.1, 2.5, and 6.1 million ha for corn, sugarcane, sweet sorghum, and pine, respectively), annual N fertilization (3230, 574, 396, 109 million kg N) and annual total water (54 400, 20 840, 8840, and 14 970 million m3) resources when scaled up to meet EISA renewable fuel standards production goals. This production would, in turn, offset only 17.5% of regional gasoline consumption on a gross basis, and substantially less when evaluated on a net basis. Utilization of existing waste biomass sources may ameliorate these effects, but does not obviate the need for dedicated primary feedstock production. Careful scrutiny of environmental trade-offs is necessary before embracing aggressive ethanol production mandates. [source]

Assessing the results of scenarios of climate and land use changes on the hydrology of an Italian catchment: modelling study

HYDROLOGICAL PROCESSES, Issue 19 2010
Daniela R. D'Agostino
Abstract Hydrological models are recognized as valid scientific tools to study water quantity and quality and provide support for the integrated management and planning of water resources at different scales. In common with many catchments in the Mediterranean, the study catchment has many problems such as the increasing gap between water demand and supply, water quality deterioration, scarcity of available data, lack of measurements and specific information. The application of hydrological models to investigate hydrological processes in this type of catchments is of particular relevance for water planning strategies to address the possible impact of climate and land use changes on water resources. The distributed catchment scale model (DiCaSM) was selected to study the impact of climate and land use changes on the hydrological cycle and the water balance components in the Apulia region, southern Italy, specifically in the Candelaro catchment (1780 km2). The results obtained from this investigation proved the ability of DiCaSM to quantify the different components of the catchment water balance and to successfully simulate the stream flows. In addition, the model was run with the climate change scenarios for southern Italy, i.e. reduced winter rainfall by 5,10%, reduced summer rainfall by 15,20%, winter temperature rise by 1·25,1·5 °C and summer temperature rise by 1·5,1·75 °C. The results indicated that by 2050, groundwater recharge in the Candelaro catchment would decrease by 21,31% and stream flows by 16,23%. The model results also showed that the projected durum wheat yield up to 2050 is likely to decrease between 2·2% and 10·4% due to the future reduction in rainfall and increase in temperature. In the current study, the reliability of the DiCaSM was assessed when applied to the Candelaro catchment; those parameters that may cause uncertainty in model output were investigated using a generalized likelihood uncertainty estimation (GLUE) methodology. The results showed that DiCaSM provided a small level of uncertainty and subsequently, a higher confidence level. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Water uptake and nutrient concentrations under a floodplain oak savanna during a non-flood period, lower Cedar River, Iowa,

HYDROLOGICAL PROCESSES, Issue 21 2009
Keith E. Schilling
Abstract Floodplains during non-flood periods are less well documented than when flooding occurs, but non-flood periods offer opportunities to investigate vegetation controls on water and nutrient cycling. In this study, we characterized water uptake and nutrient concentration patterns from 2005 to 2007 under an oak savanna located on the floodplain of the Cedar River in Muscatine County, Iowa. The water table ranged from 0·5 to 2·5 m below ground surface and fluctuated in response to stream stage, plant water demand and rainfall inputs. Applying the White method to diurnal water table fluctuations, daily ET from groundwater averaged more than 3·5 mm/day in June and July and approximately 2 mm/day in May and August. Total annual ET averaged 404 mm for a growing season from mid-May to mid-October. Savanna groundwater concentrations of nitrate-N, ammonium-N, and phosphate-P were very low (mean <0·18, <0·14, <0·08 mg/l, respectively), whereas DOC concentrations were high (7·1 mg/l). Low concentrations of N and P were in contrast to high nutrient concentrations in the nearby Cedar River, where N and P averaged 7·5 mg/l and 0·13, respectively. In regions dominated by intensive agriculture, study results document valuable ecosystem services for native floodplain ecosystems in reducing watershed-scale nutrient losses and providing an oasis for biological complexity. Improved understanding of the environmental conditions of regionally significant habitats, including major controls on water table elevations and water quality, offers promise for better management aimed at preserving the ecology of these important habitats. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Water quality and hydrogeochemical characteristics of the River Buyukmelen, Duzce, Turkey

HYDROLOGICAL PROCESSES, Issue 20 2005
Rustem Pehlivan
Abstract The River Buyukmelen is located in the province of Duzce in northwest Turkey and its water basin is approximately 470 km2. The Aksu, Kucukmelen and Ugursuyu streams flow into the River Buyukmelen. It flows into the Black Sea with an output of 44 m3 s,1. The geological succession in the basin comprises limestone and dolomitic limestone of the Y,lanl, formation, sandstone, clayey limestone and marls of the Akveren formation, clastics and volcano-clastics of the Caycuma formation, and cover units comprised of river alluvium, lacutrine sediments and beach sands. The River Buyukmelen is expected to be a water source that can supply the drinking water needs of Istanbul until 2040; therefore, it is imperative that its water quality be preserved. The samples of rock, soil, stream water, suspended, bed and stream sediments and beach sand were collected from the Buyukmelen river basin. They were examined using mineralogical and geochemical methods. The chemical constituents most commonly found in the stream waters are Na+, Mg2+, SO2,4, Cl, and HCO3, in the Guz stream water, Ca2+ in the Abaza stream water, and K+ in the Kuplu stream water. The concentrations of Na+, K+, Ca2+, Mg2+, SO2,4, HCO,3, Cl,, As, Pb, Ni, Mn, Cr, Zn, Fe and U in the Kuplu and Guz stream waters were much higher than the world average values. The Dilaver, Gubi, Tepekoy, Maden, Celik and Abaza streams interact with sedimentary rocks, and the Kuplu and Guz streams interact with volcanic rocks. The amount of suspended sediment in the River Buyukmelen in December 2002 was 120 mg l,1. The suspended and bed sediments in the muddy stream waters are formed of quartz, calcite, plagioclase, clay (kaolinite, illite and smectite), muscovite and amphibole minerals. As, Co, Cd, Cr, Pb, Ni, Zn and U have all accumulated in the Buyukmelen river-bed sediments. The muddy feature of the waters is related to the petrographic features of the rocks in the basin and their mineralogical compositions, as most of the sandstones and volcanic rocks (basalt, tuffite and agglomerate) are decomposed to a clay-rich composition at the surface. Thus, the suspended sediment in stream waters increases by physical weathering of the rocks and water,rock interaction. Owing to the growing population and industrialization, water demand is increasing. The plan is to bring water from the River Buyukmelen to Istanbul's drinking-water reservoirs. According to the Water Pollution Regulations, the River Buyukmelen belongs to quality class 1 based on Hg, Cd, Pb, As, Cu, Cr, Zn, Mn, Se, Ba, Na+, Cl,, and SO2,4; and to quality class 3 based on Fe concentration. The concentration of Fe in the River Buyukmelen exceeds the limit values permitted by the World Health Organization and the Turkish Standard. Because water from the River Buyukmelen will be used as drinking water, it will have an adverse effect on water quality and humans if not treated in advance. In addition, the inclusion of Mn and Zn in the Elmali drinking-water reservoir of Istanbul and Fe in the River Buyukmelen water indicates natural inorganic contamination. Mn, Zn and Fe contents in the waters are related to geological origin. Moreover, the River Buyukmelen flow is very muddy in the rainy seasons and it is inevitable that this will pose problems during the purification process. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Urban and industrial water use in the Krishna Basin, India,

IRRIGATION AND DRAINAGE, Issue 4 2009
Daniel J. Van Rooijen
Bassin Krishna; utilisation urbaine de l'eau; utilisation industrielle de l'eau; modélisation Abstract Regional urbanization and industrial development require water that may put additional pressure on available water resources and threaten water quality in developing countries. In this study we use a combination of census statistics, case studies, and a simple model of demand growth to assess current and future urban and industrial water demand in the Krishna Basin in southern India. Water use in this "closed" basin is dominated by irrigation (61.9 billion cubic metres (BCM) yr,1) compared to a modest domestic and industrial water use (1.6 and 3.2 BCM yr,1). Total water diversion for non-irrigation purposes is estimated at 7,8% of available surface water in the basin in an average year. Thermal power plants use the majority of water used by industries (86% or 2.7 BCM yr,1), though only 6.8% of this is consumed via evaporation. Simple modelling of urban and industrial growth suggests that non-agricultural water demand will range from 10 to 20 BCM by 2030. This is 14,28% of basin water available surface water for an average year and 17,34% for a year with 75% dependable flow. Although water use in the Krishna Basin will continue to be dominated by agriculture, water stress, and the fraction of water supplies at risk of becoming polluted by urban and industrial activity, will become more severe in urbanized regions in dry years. Copyright © 2008 John Wiley & Sons, Ltd. L'urbanisation régionale et le développement industriel demandent de l'eau, ce qui peut augmenter la pression sur les ressources en eau disponibles dans les pays en développement. Dans cette étude nous utilisons une combinaison de données de recensement, des études de cas et un modèle simple de croissance de la demande pour évaluer la demande en eau urbaine et industrielle actuelle et future dans le bassin Krishna en Inde du sud. Les usages de l'eau dans ce bassin « fermé » sont dominés par l'irrigation (61.9 milliards de m3/an) alors que les usages domestiques et industriels sont modestes (1.6 et 3.2 milliards de m3/an). L'eau utilisée en dehors de l'irrigation est estimée à 7 ,8% de l'eau de surface disponible dans le bassin en année moyenne. Les centrales thermiques utilisent la plus grosse partie de l'eau allouée aux industries (86% ou 2.7 milliards de m3/an) bien que seulement 6.8% de cette quantité soit consommé par évaporation. Une modélisation simple de la croissance urbaine et industrielle suggère que la demande non-agricole d'eau variera de 10 à 20 milliards de m3/an d'ici à 2030. C'est 14,28% de l'eau de surface disponible du bassin en année moyenne et 17,34% de l'écoulement garanti à 75%. Bien que l'utilisation de l'eau dans le bassin Krishna continue à être dominée par l'agriculture, la tension sur l'eau peut devenir plus sévère en année sèche dans les régions urbanisées avec en outre le risque d'une pollution par l'activité urbaine et industrielle. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Constraints to Drought Contingency Planning in Spain: The Hydraulic Paradigm and the Case of Seville

JOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2000
Leandro Del Moral Ituarte
Spain is equipped with an extensive hydraulic infrastructure, aimed at the correction of temporal and spatial irregularities in the availability of water resources. This structural network, mainly based on surface water, is the manifestation of the traditional hydraulic paradigm, which has technical, economic, socio-political and cultural ramifications. The traditional water management perspective tends to view drought as the structural deficit between water demand and water regulation capacity. This conceptualisation of drought led primarily to a structural response, while ignoring the need for drought risk assessment and water crisis management rules. The traditional hydraulic paradigm can, paradoxically, be regarded as one of the main constraints to the development of drought contingency planning and drought management. However, a new dynamism has entered the water policy arena, which encompasses elements of both innovation and persistence of the traditional perception. This dynamism is analysed through the Seville water management system, which is often affected by drought and severe water crises. [source]

AN EMPIRICAL SURVEY OF RESIDENTIAL WATER DEMAND MODELLING

JOURNAL OF ECONOMIC SURVEYS, Issue 5 2008
Andrew C. Worthington
Abstract The increased reliance on demand-side management policies as an urban water consumption management tool has stimulated considerable debate among economists, water utility managers, regulators, consumer interest groups and policymakers. In turn, this has fostered an increasing volume of literature aimed at providing best-practice estimates of price and income elasticities, quantifying the impact of non-price water restrictions and gauging the impact of non-discretionary environmental factors affecting residential water demand. This paper provides a synoptic survey of empirical residential water demand analyses conducted in the last 25 years. Both model specification and estimation and the outcomes of the analyses are discussed. [source]

Irrigation production functions with water-capital substitution

AGRICULTURAL ECONOMICS, Issue 1 2009
Uri Shani
Irrigation scheduling; Technology adoption; Water-yield relationship; Dynamic bio-economics Abstract The dynamics of biomass growth implies that the yield of irrigated crops depends, in addition to the total amount of water applied, on irrigation scheduling during the growing period. Advanced irrigation technologies relax constraints on irrigation rates and timing, allowing us to better adjust irrigation scheduling to the varying needs of the plants along the growing period. Irrigation production functions, then, should include capital (or expenditures on irrigation equipment) in addition to aggregate water. We derive such functions and study their water-capital substitution properties. Implications for water demand and adoption of irrigation technologies are investigated. A numerical example illustrates these properties. [source]

Effects of Urban Spatial Structure, Sociodemographics, and Climate on Residential Water Consumption in Hillsboro, Oregon,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2010
Lily House-Peters
House-Peters, Lily, Bethany Pratt, and Heejun Chang, 2010. Effects of Urban Spatial Structure, Sociodemographics, and Climate on Residential Water Consumption in Hillsboro, Oregon. Journal of the American Water Resources Association (JAWRA) 46(3):461-472. DOI: 10.1111/j.1752-1688.2009.00415.x Abstract:, In the Portland metropolitan area, suburban growth in cities such as Hillsboro is projected to increase as people seek affordable housing near a burgeoning metropolis. The most significant determinants for increases in water demand are population growth, climate change, and the type of urban development that occurs. This study analyzes the spatial patterns of single family residential (SFR) water consumption in Hillsboro, Oregon, at the census block scale. The following research questions are addressed: (1) What are the significant determinants of SFR water consumption in Hillsboro, Oregon? (2) Is SFR water demand sensitive to drought conditions and interannual climate variation? (3) To what magnitude do particular census blocks react to drought conditions and interannual climate variation? Using ordinary least squares multiple regression and spatial regression methods, we found that base use, representing indoor water use, is dependent on household size and that seasonal use, representing external water use is dependent on both education level and the size of the property's outdoor space. Spatial analysis techniques determined that although the water demand of the study area as a whole is not sensitive to drought conditions, certain individual census blocks do respond with a higher magnitude of water use. The most climate-sensitive census blocks tend to contain newer and larger homes, and have higher property values and more affluent and well-educated residents. [source]

A Retrospective Look at the Water Resource Management Policies in Nassau County, Long Island, New York,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2008
Daniel J. St. Germain
Abstract:, The residents of Nassau County Long Island, New York receive all of their potable drinking water from the Upper Glacial, Jameco/Magothy (Magothy), North Shore, and Lloyd aquifers. As the population of Nassau County grew from 1930 to 1970, the demand on the ground-water resources also grew. However, no one was looking at the potential impact of withdrawing up to 180 mgd (7.9 m3/s) by over 50 independent water purveyors. Some coastal community wells on the north and south shores of Nassau County were being impacted by saltwater intrusion. The New York State Legislature formed a commission to look into the water resources in 1972. The commission projected extensive population growth and a corresponding increase in pumping resulting in a projected 93.5 to 123 mgd (4.1 to 5.5 m3/s) deficit by 2000. In 1986, the New York Legislature passed legislation to strengthen the well permit program and also establish a moratorium on new withdrawals from the Lloyd aquifer to protect the coastal community's only remaining supply of drinking water. Over 30 years has passed since the New York Legislature made these population and pumping projections and it is time to take a look at the accuracy of the projections that led to the moratorium. United States Census data shows that the population of Nassau County did not increase but decreased from 1970 to 2000. Records show that pumping in Nassau County was relatively stable fluctuating between 170 and 200 mgd (7.5 to 8.8 m3/s) from 1970 to 2004, well below the projection of 242 to 321 mgd (10.6 to 14.1 m3/s). Therefore, the population and water demand never grew to projected values and the projected threat to the coastal communities has diminished. With a stable population and water demand, its time to take a fresh look at proactive ground-water resource management in Nassau County. One example of proactive ground-water management that is being considered in New Jersey where conditions are similar uses a ground-water flow model to balance ground water withdrawals, an interconnection model to match supply with demand using available interconnections, and a hydraulic model to balance flow in water mains. New Jersey also conducted an interconnection study to look into how systems with excess capacity could be used to balance withdrawals in stressed aquifer areas with withdrawals in unstressed areas. Using these proactive ground-water management tools, ground-water extraction could be balanced across Nassau County to mitigate potential impacts from saltwater intrusion and provide most water purveyors with a redundant supply that could be used during water emergencies. [source]

CLIMATE CHANGE IMPACTS ON WATER RESOURCES OF THE TSENGWEN CREEK WATERSHED IN TAIWAN,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2001
Ching-pin Tung
ABSTRACT: This study presents a methodology to evaluate the vulnerability of water resources in the Tsengwen creek watershed, Taiwan. Tsengwen reservoir, located in the Tsengwen creek watershed, is a multipurpose reservoir with a primary function to supply water for the ChiaNan Irrigation District. A simulation procedure was developed to evaluate the impacts of climate change on the water resources system. The simulation procedure includes a streamflow model, a weather generation model, a sequent peak algorithm, and a risk assessment process. Three climate change scenarios were constructed based on the predictions of three General Circulation Models (CCCM, GFDL, and GISS). The impacts of climate change on streamflows were simulated, and, for each climate change scenario, the agricultural water demand was adjusted based on the change of potential evapotranspiration. Simulation results indicated that the climate change may increase the annual and seasonal streamflows in the Tsengwen creek watershed. The increase in streamflows during wet periods may result in serious flooding. In addition, despite the increase in streamflows, the risk of water deficit may still increase from between 4 and 7 percent to between 7 and 13 percent due to higher agricultural water demand. The simulation results suggest that the reservoir capacity may need to be expanded. In response to the climate change, four strategies are suggested: (1) strengthen flood mitigation measures, (2) enhance drought protection strategies, (3) develop new water resources technology, and (4) educate the public. [source]

Urban,agricultural water appropriation: the Hyderabad, India case

THE GEOGRAPHICAL JOURNAL, Issue 1 2010
MATTIA CELIO
With the urbanisation drive comes steady growth in urban water demand. Although in the past this new demand could often be met by tapping unclaimed water sources, this option is increasingly untenable in many regions where little if any unclaimed water remains. The result is that urban water capture, and the appropriation of associated physical and institutional infrastructure, now often implies conflict with other existing uses and users. While the urbanisation process has been studied in great depth, the processes and, critically, impacts of urban water capture and appropriation are not well researched or understood. This paper undertakes a critical examination of the specific case of Hyderabad, one of India's fastest growing cities, to shed light more generally on the process of water capture by cities and the resultant impacts on pre-existing claims, particularly agriculture. It does this by examining the history and institutional response to Hyderabad's urban,rural water contest; how the results of that contest are reflected in surface and groundwater hydrology; and the eventual impacts on agriculture. The findings show that the magnitude, and sometimes even direction, of impact from urban water transfer vary in space and time and depend on location-specific rainfall patterns, the nature of existing water infrastructure and institutions, and farmers' adaptive capacities and options, notably recourse to groundwater. Broader consideration of the specific findings provides insights into policy mechanisms to reduce the possible negative impacts from the global, and seemingly inexorable, flow of water to the world's growing cities. [source]

Environmental challenges in the energy sector: a chemical engineering perspective,

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2010
Philippe A. Tanguy
Abstract The supply of energy in sufficient quantities and the access to clean water are among the most significant global challenges to address in the decades to come, as these are key elements of human well-being and further development. These challenges are of course related, and future practices must consider their connectivity. As the present energy system is clearly reaching its limits in terms of sustainability, new approaches have been proposed based on much improved energy efficiency, development of renewable and new energy sources, and the use of carbon capture and storage for fossil resources. The industrial deployment of these alternate scenarios is intrinsically related to the availability of water on a large scale. Because the access to freshwater is becoming scarce in many countries, better water practices and the exploitation of new water resources must be developed for the supply of industrial water. This paper begins with a brief description of our present energy system based on fossil resources, this being a legacy of the industrial revolution. We then review the main drivers supporting the energy and water demand, and the constraints they are facing. The final section considers several chemical engineering challenges that arise when proposing ways of dealing with the energy-environment nexus in the future. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Household size and residential water demand: an empirical approach,

AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 1 2010
Fernando Arbués
The effectiveness of pricing policies depends on the price elasticity of consumption. It is well documented that residential demand for water is influenced by heterogeneity associated with differences in the size of the household and socioeconomic characteristics. In this paper, we focus on household size. Our initial hypothesis is that users' sensitivity to changes in price is different depending on the number of household members. To this end, we carry out an empirical estimation of urban water demand in Zaragoza (Spain) distinguishing between households with different sizes using data at the individual level. As far as we are aware, this approach to urban residential water demand is new in the literature. The analysis suggests that all households are sensitive to prices regardless of size. A more relevant finding is that small households are more sensitive to price changes. [source]

Price elasticity of water allocations demand in the Goulburn,Murray Irrigation District,

AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 1 2008
Sarah Wheeler
Bid prices for the demand and supply of water allocations between 2001 and 2007, and average monthly prices paid for water allocations from 1997 to 2007 in the Goulburn,Murray Irrigation District are analysed to estimate price elasticities. Based on bid prices, the price elasticity of demand for water allocations appears highly elastic, with elasticities strongly influenced by the season and drought. The price elasticity of supply for water allocations is also elastic, albeit less elastic than demand. Using actual prices paid, water demand is negatively related to price and is inelastic, and appears to be most influenced by demand the previous month, drought and seasonality factors. [source]

Reduction of the Water Demand in the Process Industry by Production-Integrated Application of the Catalytic Electrolysis,

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2004
M. Forstmeier
In many process industry applications fresh water demand can be reduced significantly by production-integrated electrolytic disinfection of the process water. This contribution deals with the basic principles of electrolytic water disinfection and presents two case studies: application of the proposed method during the production of liquid detergents and during a metallurgical production process. [source]

Predictability of river flow and suspended sediment transport in the Mississippi River basin: a non-linear deterministic approach

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2005
Bellie Sivakumar
Abstract As the Mississippi River plays a major role in fulfilling various water demands in North America, accurate prediction of river flow and sediment transport in the basin is crucial for undertaking both short-term emergency measures and long-term management efforts. To this effect, the present study investigates the predictability of river flow and suspended sediment transport in the basin. As most of the existing approaches that link water discharge, suspended sediment concentration and suspended sediment load possess certain limitations (absence of consensus on linkages), this study employs an approach that presents predictions of a variable based on history of the variable alone. The approach, based on non-linear determinism, involves: (1) reconstruction of single-dimensional series in multi-dimensional phase-space for representing the underlying dynamics; and (2) use of the local approximation technique for prediction. For implementation, river flow and suspended sediment transport variables observed at the St. Louis (Missouri) station are studied. Specifically, daily water discharge, suspended sediment concentration and suspended sediment load data are analysed for their predictability and range, by making predictions from one day to ten days ahead. The results lead to the following conclusions: (1) extremely good one-day ahead predictions are possible for all the series; (2) prediction accuracy decreases with increasing lead time for all the series, but the decrease is much more significant for suspended sediment concentration and suspended sediment load; and (3) the number of mechanisms dominantly governing the dynamics is three for each of the series. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Climatic influences and anthropogenic stressors: an integrated framework for streamflow management in Mediterranean-climate California, U.S.A.

FRESHWATER BIOLOGY, Issue 2010
THEODORE E. GRANTHAM
Summary 1. In Mediterranean and other water-stressed climates, water management is critical to the conservation of freshwater ecosystems. To secure and maintain water allocations for the environment, integrated water management approaches are needed that consider ecosystem flow requirements, patterns of human water demands and the temporal and spatial dynamics of water availability. 2. Human settlements in Mediterranean climates have constructed water storage and conveyance projects at a scale and level of complexity far exceeding those in other, less seasonal climates. As a result, multiple ecological stressors associated with natural periods of flooding and drying are compounded by anthropogenic impacts resulting from water infrastructure development. 3. Despite substantial investments in freshwater ecosystem conservation, particularly in California, U.S.A., success has been limited because the scales at which river management and restoration are implemented are often discordant with the temporal and spatial scales at which ecosystem processes operate. Often, there is also strong social and political resistance to restricting water allocation to existing consumptive uses for environmental protection purposes. Furthermore, institutions rarely have the capacity to develop and implement integrated management programmes needed for freshwater ecosystem conservation. 4. We propose an integrated framework for streamflow management that explicitly considers the temporal and spatial dynamics of water supply and needs of both human and natural systems. This approach makes it possible to assess the effects of alternative management strategies to human water security and ecosystem conditions and facilitates integrated decision-making by water management institutions. 5. We illustrate the framework by applying a GIS-based hydrologic model in a Mediterranean-climate watershed in Sonoma County, California, U.S.A. The model is designed to assess the hydrologic impacts of multiple water users distributed throughout a stream network. We analyse the effects of vineyard water management on environmental flows to (i) evaluate streamflow impacts from small storage ponds designed to meet human water demands and reduce summer diversions, (ii) prioritise the placement of storage ponds to meet human water needs while optimising environmental flow benefits and (iii) examine the environmental and social consequences of flow management policies designed to regulate the timing of diversions to protect ecosystem functions. 6. Thematic implications: spatially explicit models that represent anthropogenic stressors (e.g. water diversions) and environmental flow needs are required to address persistent and growing threats to freshwater biodiversity. A coupled human,natural system approach to water management is particularly useful in Mediterranean climates, characterised by severe competition for water resources and high spatial and temporal variability in flow regimes. However, lessons learned from our analyses are applicable to other highly seasonal systems and those that are expected to have increased precipitation variability resulting from climate change. [source]

Water table fluctuations under three riparian land covers, Iowa (USA)

HYDROLOGICAL PROCESSES, Issue 18 2007
Keith E. Schilling
Abstract Water table depth is known to play an important role in nitrogen cycling in riparian zones, but little detailed monitoring of water table fluctuations has been reported. In this study, results of high-resolution water table monitoring under three common riparian land covers (forest, cool season grass, corn) were analysed to gain a better understanding of the relation of vegetation cover to water table depth. Three riparian wells located at the Neal Smith National Wildlife Refuge in Jasper County, Iowa, were instrumented with data loggers to record hourly water table behaviour from July to December 2004. Water table depth under the forest showed a diurnal pattern of rising and falling water levels, whereas the grass and corn exhibited a stepped pattern of greater drawdown during the day and less drainage at night. Clear daytime and night-time water table signals were related to daily plant water demands and lateral groundwater flow. Using two estimates of specific yield, hourly and daily ET rates were estimated to be higher under the forest cover than the grass and corn, with peak ET rates in July ranging from 5·02 to 6·32 mm day,1 for forest and from 1·81 to 4·13 mm day,1 for corn and grass. Following plant senescence in October, water table declines were associated with lateral flow to Walnut Creek. The results from this study suggest that consideration should be given to monitoring water table behaviour more frequently to capture daily and seasonal patterns related to riparian vegetation type. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Multiple-use management in a large irrigation system: an assessment of technical constraints to integrating aquaculture within irrigation canals,

IRRIGATION AND DRAINAGE, Issue 1 2005
Q. Li
Abstract Many large-scale irrigation systems, originally planned only for irrigation supply, are de facto multiple-use systems, which deliver water also for bathing, laundry, livestock watering, fisheries and other environmental functions. The importance of non-irrigation uses to the livelihoods of the rural poor has generally been ignored both in planning and operating these systems. An improved understanding of competition and complementarity of all water demands is essential for effective multiple-use management. This paper focuses in detail on one particular non-consumptive use: fish farming. The underlying objective is to explore the potential for, and constraints to, introducing cage-based aquaculture as a small enterprise for poor people (including landless households) living close to irrigation canals. A case study of Lower Bhavani Project in Tamil Nadu, India, provides evidence of technical constraints and challenges for irrigation engineers. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Securing water for people, crops, and ecosystems: New mindset and new priorities

NATURAL RESOURCES FORUM, Issue 2 2003
Sandra L Postel
A fundamentally new approach to water and human development will be needed during this new century if we are to secure sufficient freshwater to meet the needs of some 9 billion people while at the same time protecting the critical ecosystem services upon which the human economy depends. Signs of unsustainable water use , including falling water tables, shrinking lakes, and the drying up of rivers and streams , are widespread and spreading. In many regions, greater modification and appropriation of freshwater systems for human purposes will yield greater costs than benefits and create the risk of irreversible losses of species and ecosystem services. A new mindset is needed to guide water use and management in this new century, one that views the human water economy as a subset of nature's water economy. Living within nature's limits will require that societies satisfy the basic needs of people and ecosystems before non-essential water demands are met. It will require on the order of a doubling of water productivity. And it will require stronger institutions to encourage equitable sharing of water to alleviate tensions within and between countries. [source]