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Irrigation District (irrigation + district)

Distribution by Scientific Domains

Engineering	70%
Business, Economics, Finance and Accounting	23%

Selected Abstracts

Automation of the East Bench irrigation main canal,

IRRIGATION AND DRAINAGE, Issue 4 2006
Blair L. Stringam
automation; écluses; algorithme de contrôle; irrigation Abstract Canal automation equipment in the East Bench Irrigation District in Dillon, Montana, was over 30 years old and needed to be replaced. Portions of the old automation system were salvaged in an attempt to reduce rehabilitation costs. Because wiring diagrams were not available for the old control system, time would have been saved if the old control system were completely removed and replaced with a completely new system. Data communication via radio and bubbler water level sensors proved to be troublesome. After three seasons of operation, problems with the new automation system were corrected, but it became evident that a technician was needed to maintain the system. Copyright © 2006 John Wiley & Sons, Ltd. Les equipements de fonctionnement automatique des canaux âgés plus de trente ans qui se trouve dans le East Bench Irrigation District à Dillon, Montana, avait besoin de remplacement. Une partie de l'outillage ancien avait été récupérée dans l'espoir de diminuer les frais de réhabilitation. Au fait que diagrammes schématiques du système ancien n'éxistaient plus, on aurait gagné du temps par l'abandon complet de l'ancien système et son remplacement par un nouveau système. La communication d'information scientifique par radio et par instruments d'eau bouillonant, dans le nouveau système, s'est révélée problématique. A la fin de trois années d'opération, les problèmes du nouveau système ont été corrigés, mais on a realisé la nécessité d'un technicien pour maintenir le système. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Drainage and salinity assessment in the Huinong Canal Irrigation District, Ningxia, China,

IRRIGATION AND DRAINAGE, Issue 2 2005
Peter Hollanders
irrigation; drainage; salinisation; développement durable Abstract In the Huinong Canal Irrigation District, Ningxia, China, annually almost half of the amount of irrigation water, which is supplied from the Yellow River, is drained back to the river through an open drainage system. Waterlogging and salinization occur in parts of the irrigated area and part of the water drains to the surrounding desert. While 85,90% of inflow to the area is irrigation water there are good possibilities for water saving. To analyse water movement at field level and resulting drainage needs, from autumn 1998 until spring 2001 observations were made in two experimental areas: Pingluo and Huinong. The data were used for the calibration and validation of three computer models: SWAP, MODFLOW and DUFLOW. Different scenarios of water and salt behaviour in the unsaturated and saturated zone were simulated, as well as the flow through one of the main drains. The effects of various irrigation amounts and groundwater tables on crop growth, percolation and drainage needs were analysed. The present average irrigation water application during the growing season is 630,mm. On average 15% of the supplied water (665 million m3,yr,1) remains in the area. This is mainly irrigation water that was not used by the crops and did not reach the drainage system. It was found that an irrigation level of 75% of the present practice with a groundwater table of 1.0,m below the surface during the growing season gave the best results. Under such a practice the soil salinity will fluctuate around 3,3.5,dS,m,1, resulting in a good growth of wheat and a yield reduction for maize of about 20%. When adequate amounts of irrigation water are supplied in combination with local drainage improvements, the areas with middle and low-yielding crops can be reduced, as well as the area of wasteland. Copyright © 2005 John Wiley & Sons, Ltd. Annuellement presque la moitié de la quantité d'eau d'irrigation dans le district d'irrigation du canal Huinong, Ningxia, Chine, alimenté par la Rivière Jaune, est retournée à la rivière par un système de drainage à ciel ouvert. Des cas de saturation d'eau et de salinisation surgissent dans certaines parties de la zone irriguée et une partie de l'eau suinte vers le désert environnant. Comme 85,90% de l'entrée de l'eau dans la zone est de l'eau d'irrigation il y a de bonnes possibilités pour économiser de l'eau. Pour analyser la circulation de l'eau au niveau du champ et la nécessité de drainage des observations ont été effectuées pendant la période d'automne 1998 jusqu'au printemps 2001 dans deux zones expérimentales, Pingluo et Huinong. Les données rassemblées ont servi pour le calibrage et la validation de trois modèles informatiques: SWAP, MODFLOW et DUFLOW. Ces modèles ont été employés pour simuler plusieurs scénarios de comportement de l'eau et du sel dans la zone non saturée et dans la zone saturée tout comme l'écoulement par un des tuyaux d'écoulement principaux: le cinquième tuyau d'écoulement. L'effet de l'apport de différentes quantités d'eau d'irrigation, de différents niveaux de la nappe phréatique sur la croissance des cultures, la percolation et la nécessité de drainage a été analysé. L'actuel apport d'eau d'irrigation est de 630,mm en moyenne pendant la saison de croissance. Quinze pour cent en moyenne de l'eau fournie (665 millions m3/année) reste dans la zone, principalement de l'eau d'irrigation qui n'a pas servi aux cultures et qui n'a pas atteint le système de drainage. Un niveau d'irrigation représentant 75% des valeurs actuelles et une surface de la nappe phréatique de 1.0,m sous la surface donnent les meilleurs résultats pendant la saison de croissance. De tels apports entretiennent une salinisation du sol qui fluctuera entre environ 3 et 3.5,dS,m,1, donnant un bon résultat de la croissance du blé et une diminution du rendement pour le maïs d'environ 20%. Lorsque l'alimentation par des quantités adéquates d'eau d'irrigation sera assurée en combinaison avec des améliorations du drainage local, la zone donnant des récoltes moyennes et basses peut être réduite ainsi que les zones incultes. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Farm size, irrigation practices, and on-farm irrigation efficiency,

IRRIGATION AND DRAINAGE, Issue 1 2005
R. K. Skaggs
Abstract Relationships between farm size, irrigation practices, and on-farm irrigation efficiency in the Elephant Butte Irrigation District, New Mexico, USA are explored using 2001 water delivery data supplied by the irrigation district. The study area is experiencing rapid population growth, development, and competition for existing water supplies. It is conventionally assumed that in the future water will be transferred from agriculture to other uses. Analysis of pecan orchard water delivery data, fieldwork, and interviews with irrigators found extremely long irrigation durations, inefficient irrigation practices, inadequate on-farm infrastructure, and lack of interest in making improvements to the current irrigation system or methods on the smallest farms. These findings are attributed to the nature of residential/lifestyle or retirement agriculture. Irrigation practices on large, commercial orchards are notably different from the smallest farms: irrigation event durations are shorter, less water is applied, and the producers are commercially oriented. With respect to future increases in the efficiency of irrigation water usage, large, commercially oriented producers already have a high level of physical efficiency. Small producers appear to view irrigation as a consumptive, recreational, social, or lifestyle activity, rather than an income-generating pursuit, thus the cost of inducing changes in their practices may be extremely high. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Optimization of water management in the RUT Irrigation District, Colombia,

IRRIGATION AND DRAINAGE, Issue 1 2004
Herman Depeweg
canaux d'irrigation; régulation de canaux; simulation des écoulements en canal Abstract The RUT Irrigation District is a flat polder area with an infrastructure for irrigation, drainage and flood protection. Water is pumped out for drainage, mainly during the wet season and is pumped in for irrigation during the two growing seasons. The RUT Irrigation District is one of the 16 districts that were transferred by the Colombian government to a water users' association. During this process the farmers agreed to take over the management and to give up governmental subsidies. It appeared that the farmers grossly underestimated the future energy costs and nowadays they complain about high costs for operation and maintenance of the pumping stations. In addition, the service provided is not adequate and the condition of the pumps is declining. The supplementary irrigation is based on the rainfall deficit, but a distinct criterion to supply water according to daily rainfall and cropping calendar does not exist. Hence, it is possible that more water than required is supplied to the area, affecting not only the pumping costs for irrigation but also for drainage. The present situation has been evaluated with a water balance at scheme level and an analysis of the measured groundwater fluctuations. Consecutively, a water balance at field level with an unsaturated groundwater flow model has been simulated to determine the irrigation requirements, yield reduction and drain flow based on a 20-year analysis. The water balance at field level and the one-, two- and three-day rainfall with a return period of 5 years resulted in design drain flows. Finally, these flows were used in hydrodynamic simulations to analyse the pumping requirements for optimal drainage. The simulations also indicated the inundated areas to be expected for different rainfall intensities and frequencies. Copyright © 2004 John Wiley & Sons, Ltd. Le district de RUT possède un système d'irrigation et de drainage avec une protection contre les inondations. L'eau est non seulement pompée pour assurer le drainage du polder durant la saison humide, mais aussi pour alimenter le système d'irrigation durant les deux saisons agricoles. Le district de RUT est l'un des seize districts transférés par le gouvernement colombien à une association d'usagers de l'eau. Durant ce transfert, les exploitants agricoles ont accepté de prendre en charge la gestion et d'abandonner les aides gouvernementales. Il est apparu alors que les exploitants agricoles se plaignent des couts élevés pour l'opération et la maintenance des stations de pompages. De plus, le service fourni n'est pas adéquat et les pompes se détériorent. L'irrigation de complément est fonction des précipitations, mais il n'existe pas de critère précis pour la fourniture d'eau en fonction de précipitations quotidiennes ou du calendr des récoltes. Il est ier possible qu'une quantité d'eau supérieure à celle requise soit apportée au système, affectant non seulement les exigences de pompage pour l'irrigation mais aussi pour le drainage. L'évaluation de la situation actuelle est basée sur un bilan hydrique à l'échelle de système et sur une analyse des fluctuations des eaux souterraines. Par la suite, un bilan hydrique a l'échelle de la campagne délivré par le model WASIM a été utilisé pour déterminer les exigences d'irrigation, la réduction des récoltes et le débit dans le drain basé sur une simulation de 20 ans. Enfin, le drain principal fut simulé avec DUFLOW pour analyser les caractéristiques du pompage pour le drainage utilisant le débit de drainage fourni par un bilan hydrique pour des durées deun, deux et trois jours de pluie fréquence de quinquennale. La simulation a aussi permis d'identifier les étendues des inondations pour différentes intensités et fréquences de pluie. Copyright © 2004 John Wiley & Sons, Ltd. [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]

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]

Pedotransfer functions for solute transport parameters of Portuguese soils

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2001
M. C. Gonc, alves
Summary The purpose of this study is to quantify solute transport parameters of fine-textured soils in an irrigation district in southern Portugal and to investigate their prediction from basic soil properties and unsaturated hydraulic parameters. Solute displacement experiments were carried out on 24 undisturbed soil samples by applying a 0.05 m KCl pulse during steady flow. The chloride breakthrough curves (BTCs) were asymmetric, with early breakthrough and considerable tailing characteristic of non-equilibrium transport. The retardation factor (R), dispersion coefficient (D), partitioning coefficient (,), and mass transfer coefficient (,) were estimated by optimizing the solution of the non-equilibrium convection,dispersion equation (CDE) to the breakthrough data. The solution could adequately describe the observed data as proved by a median of 0.972 for the coefficient of determination (r2) and a median for the mean squared error (MSE) of 5.1 × 10,6. The median value for R of 0.587 suggests that Cl, was excluded from a substantial part of the liquid phase. The value for , was typically less than 0.5, but the non-equilibrium effects were mitigated by a large mass transfer coefficient (, > 1). Pedotransfer functions (PTFs) were developed with regression and neural network analyses to predict R, D, , and , from basic soil properties and unsaturated hydraulic parameters. Fairly accurate predictions could be obtained for logD (r2 , 0.9) and , (r2 , 0.8). Prediction for R and log, were relatively poor (r2 , 0.5). The artificial neural networks were all somewhat more accurate than the regression equations. The networks are also more suitable for predicting transport parameters because they require only three input variables, whereas the regression equations contain many predictor variables. [source]

An optimal water allocation for an irrigation district in Pingtung County, Taiwan,

IRRIGATION AND DRAINAGE, Issue 3 2009
Yun Cheng
allocation optimale de l'eau; utilisation conjointe; programmation linéaire Abstract This paper presents a linear programming model to study the conjunctive use of surface water and groundwater for optimal water allocation in Taiwan. Increasing demand for water emphasizes the proper need for effective planning and development of irrigated resources. A groundwater simulation model was performed to construct the hydrogeological structure of the regional Pingtung Plain in the southwest part of Taiwan and the optimal withdrawal of three irrigation areas in Pingtung Plain was analysed. The optimal ratios for allocating water of three canals are analysed in this research. The optimal distribution rate of each canal depends on the season, irrigation methods and crops, which are two paddy rice and one upland crop. After simulation of various scenarios, optimal simulation results show that the minimal amount of required groundwater and the maximum amount of excess water amounts in the area can be satisfied by current agricultural practices. Copyright © 2008 John Wiley & Sons, Ltd. Cet article présente un modèle de programmation linéaire pour étudier l'utilisation conjointe de l'eau de surface et des eaux souterraines pour l'allocation optimale de l'eau à Taiwan. La demande croissante d'eau souligne le besoin de planification effective et de développement des ressources pour l'irrigation. Un modèle hydrogéologique a été construit pour représenter la structure de la plaine Pingtung dans le sud-ouest de Taiwan et pour analyser le prélèvement optimal sur trois périmètres irrigués de la plaine de Pingtung. Les ratios optimaux pour allouer l'eau aux trois canaux sont analysés dans cette recherche. Le taux optimal de distribution de chaque canal dépend de la saison, des méthodes d'irrigation et des cultures qui sont ici deux récoltes de riz et une culture de montagne. Après la simulation de différents scénarios, les résultats optimisés montrent que la quantité minimale d'eau souterraine exigée ajoutée à la quantité d'eau en excès disponible dans le secteur peut satisfaire les pratiques agricoles actuelles. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Farm size, irrigation practices, and on-farm irrigation efficiency,

Spot water markets and risk in water supply

AGRICULTURAL ECONOMICS, Issue 2 2005
Javier 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]

Flume or weir continuous water flow rate recorder for irrigation use,,

IRRIGATION AND DRAINAGE, Issue 1 2005
Blair L. Stringam
Abstract US Bureau of Reclamation projects and irrigation districts need simple, low-cost, robust devices to measure and record water use for effective water management decisions. This need has resulted in the development of a continuous flow meter and recorder (CFM). The CFM is designed to continuously measure flow rates through open channel measurement structures, such as flumes or weirs, by recording the water levels upstream. The water level measurements are then converted to flow rate using a simple weir power equation. The CFM consists of an easily programmed CPU, an LCD for displaying the flow rate and total amount of water that has passed through the measurement structure, and a water level sensor. The CFM, including a solar power supply, may be purchased for under US$1000. The majority of that cost is for the water level sensor and may be reduced depending upon the needed accuracy. Presently, some of these devices have been installed on irrigation systems in the field where they have been exposed to harsh weather conditions. Despite the harsh environments, the CFMs have been functioning as designed. This paper discusses the design, installation, and testing of the continuous flow meter. Published in © 2005 John Wiley & Sons, Ltd. [source]

Applying benchmarking and data envelopment analysis (DEA) techniques to irrigation districts in Spain

IRRIGATION AND DRAINAGE, Issue 2 2004
J. A. Rodríguez Díaz
indicateurs de performance; benchmarking; DEA Abstract In this research, the application of data envelopment analysis (DEA) is proposed as a methodology to overcome the problems related to the lack of methodology to assign the correct weightings for the calculation of indexes and to the subjectivity of the interpretations of results. DEA is a linear programming technique to determine the relative efficiencies of a company when the inputs and outputs of production units within the company are known, but the productive process itself is not. In this way, quantitative efficiencies and the weighting of any performance indicator can be assessed and compared, permitting managers to obtain a well-defined performance ranking. This is especially important when managers dispose of a limited budget. The results of the application of this methodology to Andalusian irrigation districts (Spain) are presented and discussed here. This study was used to select the most representative irrigation districts in Andalusia which were then studied in greater depth by applying the performance indicators selected by IPTRID for use by the benchmarking international program. Copyright © 2004 John Wiley & Sons, Ltd. Dans ce travail, l'utilisation de la méthode de ,,data envelopment analysis (DEA),, est analysée en tant que méthodologie capable de résoudre les problèmes liés au manque de méthodologie pour l'attribution des pondérations dans le calcul d'indices composites et à la subjectivité des comparaisons. La DEA est une technique de programmation linéaire pour déterminer les efficiences relatives d'une compagnie. Les moyens utilisés sont la connaissance des intrants et produits de la compagnie, ignorant les processus de production. De cette façon, les gestionnaires peuvent obtenir un large ensemble d'indices de gestion qui se révèle particulièrement important lorsque le gestionnaire dispose d'un budget limité. Les résultats de l'utilisation de cette méthode pour l'irrigation dans la région d'Andalousie (Espagne) sont présentés et discutés dans ce travail. Copyright © 2004 John Wiley & Sons, Ltd. [source]

WICKED WATER PROBLEMS: SOCIOLOGY AND LOCAL WATER ORGANIZATIONS IN ADDRESSING WATER RESOURCES POLICY,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2000
David M. Freeman
ABSTRACT: Water policy problems are wicked, not in an ethically deplorable sense, but in the sense that they present us with especially difficult challenges of becoming more effective in our interdisciplinary collaboration, of integrating two very different types of knowledge, of working across several socio-political units of analysis simultaneously, and of better organizing water as a common property resource. Sociology, as a discipline, does not have a particularly rich history of successful interdisciplinary collaboration on water resources research and teaching, but it potentially has a most useful contribution to make by focusing on the analysis of local common property resource organizations that operate in the interface between individual resource users and State-Federal entities. These organizations (e.g., water user associations, mutual companies, irrigation districts, acequias, conservancy districts) have been the orphans of water policy discourse but their operations are critical to undertaking more effective 21st century social analysis, research work, and action programs. Sociologists who work to better comprehend the operations of, and constraints upon, these organizations build a sociology that can better collaborate with other water-related disciplines in addressing the challenges posed by the wickedness of our water problems. [source]

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]