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Multi-objective fuzzy linear programming (MOFLP) approach is applied with four conflicting objectives, viz maximization of net benefits, employment generation, minimization of cost of cultivation and maximization of revenue generation from municipal and industrial supplies (M and I), on a water resources project (Ukai), Gujarat, India. The results from the model are reported for the most critical year (90% exceedance probability), critical year (85% exceedance probability), normal year (75% exceedance probability), and wet year (60% exceedance probability) inflow conditions. The degree of satisfaction of the proposed MOFLP model, considering all objectives together, for wet year, normal year, critical year and most critical year are found to be 0.527, 0.515, 0.50, and 0.46 respectively; and corresponding net irrigation benefits for different inflow conditions are computed as 10 611.91 Million Rs, 10 476.67 Million Rs, 8 311.0044 Million Rs, and 6 900.051 Million Rs, respectively. The proposed MOFLP model indicated that probable inflow corresponding to 75% dependability level is marginally sufficient to meet the requirement of the study area, and water availability becomes deficit in the command area for 85% dependability inflow condition. The optimized crop areas from the model, complying with the requirement of existing flood rules, and satisfying relevant conflicting objectives would help the decision makers in sustainable management of water resources in Ukai command area. Key words: multi-objective fuzzy linear programming, level of satisfaction, optimal irrigation planning, Ukai irrigation project. La programmation lineaire floue a plusieurs objectifs (MOFLP) applique quatre objectifs contradictoires, soit: la maximisation des avantages nets, la production d'emplois, la minimisation des couts de culture et la maximisation de la production de revenus provenant des municipalites et des industries (M et I), a un projet de ressources en eau (Ukai), Gujarat, Inde. Les resultats sont rapportes pour des debits entrants de l'annee la plus critique (probabilite de depassement de 90 %), d'une annee critique (probabilite de depassement de 85 %), d'une annee normale (probabilite de depassement de 75 %), et d'une annee humide (probabilite de depassement de 60 %). Le niveau de satisfaction du modele MOFLP propose, en tenant compte de tous les objectifs, etait respectivement de 0,527, 0,515, 0,50 et 0,46 pour une annee humide, normale, critique et la plus critique. L'avantage net d'irrigation pour divers debits entrants correspondants est respectivement de 10 611,91 millions Rs, 10 476,67 millions Rs, 8 311,0044 millions Rs et de 6 900,051 millions Rs. Le modele MOFLP propose indique que le debit intrant probable pour un niveau de fiabilite de 75 % est a peine suffisant pour rencontrer les besoins de la zone d'etude, et la disponibilite de l'eau devient deficitaire dans la zone de commande pour une fiabilite de debit entrant de 85 %. Les zones de recolte optimisees definies par le modele, en conformite a l'exigence des regles existantes de crues et les objectifs contradictoires pertinents, aideraient les decideurs a gerer les ressources hydriques dans la zone de commande d'Ukai de maniere durable. [Traduit par la Redaction] Mots-cles: programmation lineaire floue a objectifs multiples, niveau de satisfaction, planification de l'irrigation optimale, projet d'irrigation d'Ukai., 1. Introduction Floods and droughts have become more frequent in the recent past due to changing climatic conditions across the globe; and management of water resources under such situation is [...]

Soil moisture beneath irrigated crops has traditionally been determined using point measurement methods such as neutron probes or capacitance systems. These approaches cannot measure soil moisture at depths beyond the root-zone of plants and have limited lateral coverage. It is shown that surface two-dimensional electrical resistivity tomography (ERT) can be used to map the spatial heterogeneity in soil moisture throughout a field under irrigated cotton. The case study demonstrates that ERT provides a better understanding of the pathways of water migration, and provides spatial information on how water storage changes throughout the growing season. We conclude that ERT should be integrated into farm water management surveys to delineate zones of excessive water loss due to deep drainage and to improve the positioning of point measurement methods for measuring soil moisture, thereby improving irrigation scheduling. Additional keywords: crops, resistivity imaging, vertosols, water., Introduction The suitability of two-dimensional surface electrical resistivity tomography (ERT) (Dahlin 2001), also referred to as resistivity imaging, is evaluated for mapping the spatial variability of soil moisture conditions throughout [...]

Growing concerns about limited water inputs for, and deleterious environmental outputs from, irrigation of pasture make the identification of more efficient scheduling strategies imperative. A climate-driven pasture production model is used to simulate the daily soil water deficit in the topsoil and subsoil, and so pasture production under a range of irrigation strategies. Soil water content and pasture production data from a companion paper, describing a Manawatu experiment where irrigation was applied to plots at trigger deficits of 20, 40, and 60 mm, were used to evaluate model parameters. The model was then used with 30 years of meteorological data to simulate a range of irrigation strategies at Palmerston North and Winchmore. Applying 20 mm of irrigation when a 20-mm trigger deficit is reached as opposed to 60 mm of irrigation at a 60-mm deficit increased the simulated average annual pasture response to irrigation by -80%, but this increase was at the cost of ~40% more irrigation water. A suggested alternative strategy is to apply 20 mm of irrigation whenever a 60-mm trigger deficit is reached, which in summer will be about every 5 days if no rain falls. Keeping the topsoil moist most of the time, while leaving room for rainfall in the subsoil, will increase water use efficiency (the production response per mm of irrigation) by substantially reducing the irrigation requirement and drainage excess, even though it does not maximise production. Additional keywords: climate-driven model, evaporation, evapotranspiration, irrigation scheduling, leaching, phosphorus, water use efficiency., Introduction The extra pasture production that irrigation can bring is increasingly being appreciated in New Zealand. However, there is a limited amount of water available, particularly in dry years when [...]

In closing river basins where nearly all available water is committed to existing uses, downstream irrigation projects are expected to experience water shortages more frequently. Understanding the scope for resilience and adaptation of large surface irrigation systems is vital to the development of management strategies designed to mitigate the impact of river basin closure on food production and the livelihoods of farmers. A multilevel analysis (farm-level surveys and regional assessment through remote-sensing techniques and statistics) of the dynamics of irrigation and land use in the Nagarjuna Sagar project (South India) in times of changing water availability (2000-2006) highlights that during low-flow years, there is large-scale adoption of rainfed or supplementary irrigated crops that have lower land productivity but higher water productivity, and that a large fraction of land is fallowed. Cropping pattern changes during the drought reveal short-term coping strategies rather than long-term evolutions: after the shock, farmers reverted to their usual cropping patterns during years with adequate canal supplies. For the sequence of water supply fluctuations observed from 2000 to 2006, the Nagarjuna Sagar irrigation system shows a high level of sensitivity to short-term perturbations, but long-term resilience if flows recover. Management strategies accounting for local-level adaptability will be necessary to mitigate the impacts of low-flow years but there is scope for improvement of the performance of the system. DOI: 10.1061/(ASCE)IR.1943-4774.0000225 CE Database subject headings: Irrigation systems; Water shortage; Water supply; Agriculture; Productivity; India. Author keywords: Irrigation system; Water scarcity; Management; Resilience; Coping strategies; Productivity; India.

Water application uniformity is an important performance criterion that must be considered during the design and evaluation of the microirrigation systems. This study was conducted to evaluate the water application uniformity considering field slopes. The uniformity parameters including coefficient of variation (CV), Christiansen's uniformity coefficient (UCC), distribution uniformity (DU), emitter discharge variation [q.sub.v](q max) expressed by the difference between the maximum emitter flow rate [q.sub.max] and the minimum emitter flow rate [q.sub.min] to [q.sub.max], emitter discharge variation [q.sub.v(qd)] expressed by the difference between [q.sub.max] and [q.sub.min] to design emitter flow rate [q.sub.d], emitter discharge variation [q.sub.v(qd)] expressed by the difference between [q.sub.max] and [q.sub.min] to average emitter flow rate [q.sub.(avg)], emission uniformity ([EU.sub.(q avg)]) expressed by [q.sub.min] to [q.sub.avg], and [EU.sub.(qd)] expressed by [q.sub.min] to [q.sub.d]. Furthermore, the relationships of CV versus UCC, CV versus DU, CV versus [q.sub.v(qd)], CV versus [q.sub.v(q max)], CV versus [q.sub.v(q avg)], CV versus [EU.sub.(q avg)], and CV versus [EU.sub.(qd)] were also discussed. The results of the study revealed that the field slope does not obviously affect the relationships of CV versus UCC, CV versus [q.sub.v(q max)], and CV versus [q.sub.v(q avg)] for any of the slopes evaluated, which include uphill, zero slope, and downhill. Furthermore, the effect of slope on the relationships of CV versus [EU.sub.(q avg)], CV versus [EU.sub.(qd)], and CV versus [q.sub.v(qd)] was obvious, especially when large downhill slopes with a CV > 0.05 were considered. However, the effect of slope on the relationships of CV versus DU was intermediate. Taken together, the results of this study indicated that the UCC, [q.sub.v(q max)], and [q.sub.v(q avg)] should be recommend in addition to CV when evaluating the water application uniformity of the microirrigation systems, regardless of slope, and that [q.sub.v(qd)] and [EU.sub.(qd)] should be recommend when evaluating systems placed in fields with a slope of zero or an uphill slope. DOI: 10.1061/(ASCE)IR.1943-4774.0000196 CE Database subject headings: Irrigation; Slopes. Author keywords: Uniformity; Microirrigation; Slope.

In this paper a knowledge-based model for supplementary irrigation assessment in rainfed agricultural watersheds is presented. The supplementary irrigation assessment problem is divided into different components and is modeled separately. Geographic Information System (GIS) is used to aggregate spatially varying attributes required for the modeling. A graphical user interface is developed in a GIS platform by using the ERDAS macro language tools. The model was applied to two case study areas in India: a subwatershed of Gandheshwari area (West Bengal), and Harsul watershed (Maharashtra). In the Gandheshwari subwatershed, the water availability was found to be inadequate to meet the irrigation requirement and hence the model identified the areas that can be irrigated with different outsource water supply. On the other hand, surface runoff generated in the Harsul watershed was found to be sufficient to meet the supplementary irrigation requirement, thereby showing the feasibility for supplementary irrigation in the area. Using the model, the effect of any rainfall condition can be simulated and hence appropriate measures can be taken in advance to reduce the risk of crop failure. DOI: 10.1061/(ASCE)IR.1943-4774.0000206 CE Database subject headings: Knowledge-based systems; Irrigation; Geographic information systems; Agriculture; Watersheds; Soil water. Author keywords: Knowledge-based systems; Irrigation; Geographic Information System; Multicriteria decision analysis; Agricultural watershed; Soil moisture.

A cross-section-averaged advection-dispersion equation (ADE) model was developed to simulate the transport of fertilizer in furrow irrigation. The advection and dispersion processes were solved separately at each time step by implementing a method of characteristics with cubic-spline interpolation and a time-weighted finite-difference scheme, respectively. The upstream boundary condition was a prescribed concentration. Downstream, a zero-flux boundary condition during advance and a concentration gradient following completion of advance were prescribed. Local pseudosteady state was assumed in order to apply Fischer's longitudinal dispersion equation under nonuniform and unsteady furrow flow conditions. Statistical parameters were used to evaluate the ADE model performance. DOI: 10.1061/(ASCE)IR.1943-4774.0000106 CE Database subject headings: Solutes; Fertilizers; Finite difference method; Furrow irrigation; Models. Author keywords: Fertigation; Advection-dispersion equation; Longitudinal dispersion; Finite differences; Method of characteristics; Cubic-spline interpolation.

The purpose of irrigation scheduling is to coordinate the timing and amount of water used to irrigate crops in a way that maximizes profits. Using a case study on corn production in the Havana Lowlands region, Illinois, this paper examines the extent to which the incorporation of different types of weather forecasts into irrigation scheduling can increase the profitability of irrigated agriculture. A soil water atmosphere plant (SWAP) model is employed to simulate crop yields using weather forecasts from the growing seasons during a period running from 2002 to 2006. The net profits from the modeling analysis based on the modeled soil moisture and weather forecasts are compared to that from an irrigation schedule that the farmers roughly followed in 2002. The results show that if farmers just use the real-time soil moisture information and the empirical rules set with the SWAP model, crop profits may increase by 16%; the inclusion of 7-day forecasts in a rule-based simulation model boosts the net profit by 21%. Over the 5 testing years, it is found that the proper use of the 7-day forecast can save irrigation water and increase crop yield in dry years. Next, these results are also compared to ones derived using deterministic optimization techniques that assume perfect 2-week and seasonal forecasts to assess the extent to which net profits could increase with further weather forecasting improvements. On average over the 5 testing years, the perfect 2-week and seasonal forecasts yield profits of 42% and 48%, respectively, greater than the scenario based on the 7-day weather forecasts. Furthermore we conduct a stochastic optimization analysis using the monthly probabilistic climate prediction provided by the Climate Prediction Center of the National Oceanic and Atmospheric Administration. A review of the retrieved irrigation schedule shows that the farmers at the study site sometimes applied more water than necessary and, at other times, less than the model based on a 7-day weather forecast and soil moisture simulation suggested. CE Database subject headings: Irrigation scheduling; Optimization; Weather forecasting; Agriculture; Illinois.

Abstract The adoption of decision support systems (DSS) by irrigators and other farmers has been surprisingly slow. Various explanations have been given for the slow uptake including poor system design [...]

This paper has two goals. It aims, first, to explore how the use of goal programming (GP) techniques within a Simonian-bounded rationality context can be an operational framework for dealing with the sustainable management of agricultural systems. Second, it goes on to apply this type of theoretical framework to a case study related to the sustainable management of irrigated agriculture in the Spanish Monegros District, where GP models are used to establish sensible compromises among economic and environmental criteria. doi: 10.1057/palgrave.jors.2602588 Published online 19 March 2008 Keywords: bounded rationality; environmental criteria; goal programming; irrigated agriculture; multiple criteria decision making; sustainability

Intensification of agriculture and irrigation are often considered triggers for both the flourishing and demise of civilizations. Was irrigation a key factor of state formation and urban development in northern Ethiopia? We argue that a household-based management of farmland and water would have provided a strategy sustainable over the long term and flexible enough to adjust to population expansion and contraction at the ancient capital of the Kingdom of Aksum (first millennium AD). This conclusion is based on research into environmental, archaeological and historical data concerning the forms and use of water resources together with new information originating from geoarchaeological and palaeobotanical work in the Aksum area. The results indicate that the characteristics of the environment and traditional farming system are such that intensive irrigation works were not necessary. It appears likely that ancient Aksumites utilized seasonal rainfall and water conservation methods to sustain food production. Keywords Aksum; Ethiopia; water management; agriculture; geoarchaeology.

Climate change, water supply limits, and continued population growth have intensified the search for measures to conserve water in irrigated agriculture, the world's largest water user. Policy measures that encourage adoption of water-conserving irrigation technologies are widely believed to make more water available for cities and the environment. However, little integrated analysis has been conducted to test this hypothesis. This article presents results of an integrated basin-scale analysis linking biophysical, hydrologic, agronomic, economic, policy, and institutional dimensions of the Upper Rio Grande Basin of North America. It analyzes a series of water conservation policies for their effect on water used in irrigation and on water conserved. In contrast to widely-held beliefs, our results show that water conservation subsidies are unlikely to reduce water use under conditions that occur in many river basins. Adoption of more efficient irrigation technologies reduces valuable return flows and limits aquifer recharge. Policies aimed at reducing water applications can actually increase water depletions. Achieving real water savings requires designing institutional, technical, and accounting measures that accurately track and economically reward reduced water depletions. Conservation programs that target reduced water diversions or applications provide no guarantee of saving water. agriculture | sustainability | institutions | hydrology

The effect of four different irrigation levels on the marketable yield and economic return of summer-growth lettuce was evaluated during 2005 and 2006 in Eastern Sicily, Italy. The viability of deficit irrigation was evaluated by estimating optimum applied water levels. Actual evapotranspiration ([ET.sub.0]) was estimated by combining pan evaporation measures and the Penman-Monteith approach ([ET.sub.0-PM]). The highest marketable yield of lettuce was recorded for plots receiving 100% [ET.sub.0-PM]. For deficit irrigated plots, reductions in crop production were ascribed to a decrease in lettuce weight. Crop coefficients equal to 1 determined maximum crop production values. Crop water use efficiency was maximum at a 100% [ET.sub.0-PM] level of water applied, corresponding to yield of 0.3 t [ha.sup.-1] [mm.sup.-1]. Irrigation water use efficiency reached its maximum at a 40% [ET.sub.0-PM] level, with values of 0.54 and 0.44 t [ha.sup.-1] [mm.sup.-1] during 2005 and 2006, respectively. Water applied and marketable yield of lettuce showed a significant quadratic relationship. Cost functions had a quadratic form during 2005 and a linear form during 2006. In the land-limiting condition the optimal economic levels fit the agronomic ones well. In the water-limiting condition, ranges of water deficit of 15-44% and 74-94% were as profitable as full irrigation, thus contributing to appreciable water savings. DOI: 10.1061/(ASCE)0733-9437(2008)134:4(437) CE Database subject headings: Economic factors: Evapotranspiration; Irrigation scheduling: Water management; Crops; Italy.

Abstract: A center pivot was completely automated using the temperature-time-threshold method of irrigation scheduling. An array of infrared thermometers was mounted on the center pivot, and these were used to remotely determine the crop leaf temperature as an indicator of crop water stress. We describe methods used to automatically collect and analyze the canopy temperature data and control the moving irrigation system based on the data analysis. Automatic irrigation treatments were compared with manually scheduled irrigation treatments under the same center pivot during the growing seasons of 2004 and 2005. Manual irrigations were scheduled on a weekly basis using the neutron probe to determine the profile water content and the amount of water needed to replenish the profile to field capacity. In both years, there was no significant difference between manual and automatic treatments in soybean water use efficiency or irrigation water use efficiency. The automatic irrigation system has the potential to simplify management, while maintaining the yields of intensely managed irrigation. DOI: 10.1061/(ASCE)0733-9437(2008)134:3(286) CE Database subject headings: Irrigation scheduling; Temperature; Time factors; Automation; Crops.

A model for modifying the canal delivery schedule during the dry season has been formulated to overcome the problem of low irrigation efficiency in a major irrigation project in India. Phulnakhara Distributary of the Puff main canal system (a run-of-the-river scheme) in the state of Orissa was chosen for this study. The model adopts a procedure of daily water balance simulation in paddy field and daily moisture balance simulation in nonpaddy crops field in the crop root zone. The historical canal flow data show that the prevailing delivery schedule is continuous. In addition to prevailing a continuous delivery schedule, five alternative rotational (variable discharge, constant duration, and constant frequency) schedules were considered. The alternatives considered are: 7 days canal operation followed by 7 days canal closure (7_7); 10 days canal operation followed by 10 days canal closure (10_10); 15 days canal operation followed by 15 days canal closure (15_15); 10 days canal operation followed by 7 days canal closure (10_7); and 15 days canal operation followed by 7 days canal closure (15_7). Considering both paddy and nonpaddy crops to be grown in the command during the dry season, 7 days canal operation followed by 7 days canal closure rotational schedule were found to be the best alternative. The alternative schedule 7_7 has registered weighted average seasonal evapotranspiraton (ET) of 354 mm in comparison to 347, 342, and 352 mm in 10_10, 15_15, and 10_7 schedules, respectively. In the paddy field, schedule 7_7 registered maximum of 4 days of disappearance of water as compared to 5 days and 6 days for 15_7 and 10_7 schedule, respectively. Besides creating a favorable water regime and better crop ET, this schedule saves about 10.31% of water over prevailing (actual) water supplies. DOI: 10.1061/(ASCE)0733-9437(2008)134:2(175) CE Database subject headings: Canals; Irrigation scheduling; Water supply; Crops; Water demand; Evapotranspiration.

The process of policy-making that has generated the Mexican policy model for irrigation management transfer is analyzed.

New microscale techniques have become available to assist urban designers in better water management. Urban water management has focused on two different areas: storm water and water supply. The focus of storm-water management is shifting toward low-impact development, which emphasizes better management of urban storm water through reductions in postdevelopment runoff by increasing on-site infiltration, while water supply planning has been enhanced by the emergence of end-use demand management, especially outdoor irrigation. Implementation of these two objectives requires examination of processes at smaller scales in order to evaluate changes being contemplated at a parcel level. A modeling approach is presented that incorporates decentralized options for management of both storm water and urban water supply. Management options that can be evaluated with this approach include restrictive irrigation policies and rainwater harvesting. A simpler model based upon Soil Conservation Service hydrology is then calibrated to the more complex model using a commercially available nonlinear optimizer. A method for comparison of costs and benefits from a consumer perspective is presented. DOI: 10.1061/(ASCE)0733-9496(2006)132:5(362) CE Database subject headings: Irrigation; Conservation; Water balance; Stormwater management; Benefit cost ratios; Urban areas.

In this paper, we suggest a typology for distinct types of self-management, based on who carries out the administration and operation of the irrigation system: specialized staff (bureaucratic) or the irrigators themselves (non-bureaucratic). We argue that a specialized staff for irrigation administration and operation characterizes all large systems, but that both small and medium-sized systems may be administered and operated by the irrigators themselves. Both types of organization are described, and special attention is given to the problems posed by bureaucratic organization. The effectiveness of bureaucratic or non-bureaucratic organization is treated from the analytical framework of industry, where issues of efficiency and a preferred cultural model have been framed. Finally, we propose that smallholding and non-bureaucratic self-management of irrigation are linked. Proponemos una tipologia de autogestion, basada en quien realiza la administracion y operacion en el sistema hidraulico: personal especializado (burocratico) o los mismos regantes (no burocratico). Argumentamos que el uso de personal especializado para la administracion y operacion caracteriza a todos los grandes sistemas de riego, pero que los pequenos y medianos sistemas de riego pueden ser administrados y operados por los mismos regantes. Se describe a ambos tipos de organizacion, y se da particular atencion a los problemas peculiares que derivan de una organizacion burocratica. La eficacia de la organizacion burocratica o no burocratica es tratada desde el marco analitico de la industria, donde las cuestiones de la eficiencia y el modelo cultural preferido han sido consideradas. Finalmente, se propone que hay una relacion causal entre minifundismo y administracion no burocratica. Keywords: Irrigation system, administration, self-government, irrigation management transfer, bureaucracy, traditional or indigenous knowledge, bureaucratic management, self-management, organizational levels, managers. Palabras clave: sistema de irrigacion, administracion, autogobierno, cambios administrativos de la irrigacion, burocracia, conocimiento tradicional o nativo, administracion burocratica, autoadministracion, niveles organizacionales, administradores

This paper presents a genetic algorithm (GA) model for obtaining an optimal operating policy and optimal crop water allocations from an irrigation reservoir. The objective is to maximize the sum of the relative yields from all crops in the irrigated area. The model takes into account reservoir inflow, rainfall on the irrigated area, intraseasonal competition for water among multiple crops, the soil moisture dynamics in each cropped area, the heterogeneous nature of soils, and crop response to the level of irrigation applied. The model is applied to the Malaprabha single-purpose irrigation reservoir in Karnataka State, India. The optimal operating policy obtained using the GA is similar to that obtained by linear programming. This model can be used for optimal utilization of the available water resources of any reservoir system to obtain maximum benefits. DOI: 10.106l/(ASCE)0733-9437(2006)132:2(123) CE Database subject headings: Irrigation; Algorithms; Optimization; Crops; Reservoir operation.

The Mekele Plateau, located in the semi-arid northern highland region of Ethiopia, is a drought-prone, highly degraded area. It has long been neglected by policymakers and thus recurring famine, widespread poverty, armed conflicts and mass outmigration have contributed to the near collapse of the farming systems and the livelihoods of the population. Traditional stream diversion irrigation has been practised in this area for several centuries. The systems of water management in particular may be considered inappropriate owing to the need for thriftiness in water use imposed by the local environment. The systems of headworks and canals are crude and wasteful on water. Recent interventions to improve the small-scale irrigation systems of the area have not been successful. Most interventions have preferred to introduce rainwater harvesting systems using micro-dams rather than trying to upgrade the traditional diversion schemes. Evaluation of irrigation structures in the field, interviews with key informants in government, analysis of documents and discussions with irrigators indicate that both the Ministry of Agriculture and SAERT-Commission's rainwater harvesting programmes have generally failed. The case of the most recent intervention by SAERT has failed because of myopic project planning, inadequate engineering studies, unsound designs, too short a time for implementation, and lack of full farmer involvement at different levels of project planning and implementation. KEY WORDS: Mekele Plateau, small-scale irrigation, drought-prone areas, SAERT, rainwater harvesting, traditional irrigation methods