Transjurisdictional Water Pollution Management in China: The Legal and Institutional Framework

The current study shows that the recent diesel price hike had an insignificant impact on irrigation costs incurred by diesel well owners in eastern India. Further, analysis of the farming enterprises of diesel well owners and water buyers from both diesel and electric wells confronted with a differential cost of irrigation water showed that farmers would be able to cope with a very high rise in irrigation costs through irrigation efficiency improvements and allocating more area to crops that give higher returns per unit of land and water. By doing this, they are able to maintain the farm returns.     

Rapid appraisal for improving existing canal irrigation systems

Low levels of performance on canal irrigation systems in developing countries are a major concern of many governments and aid agencies. A wide range of actions is possible to improve performance. The choice, mix and sequence of actions are often determined by professional preferences or national programmes but to fit well should be tailored for each individual irrigation system. Rapid rural appraisal techniques offer a cost‐effective approach, either through teamwork or through irrigation managers doing it themselves. In order to improve rapid appraisals, practitioners are encouraged to write about and share their techniques and experiences.     

Optimum Abstraction of Groundwater for Sustaining Groundwater Level and Reducing Irrigation Cost

Adaptation to increasing irrigation cost due to declination of groundwater level is a major challenge in groundwater dependent irrigated region. The objective of this study is to estimate the optimum abstraction of groundwater for irrigation for sustainable management of groundwater resources in Northwest Bangladesh. A data-driven model using a support vector machine (SVM) has been developed to estimate the optimum abstraction of groundwater for irrigation and a multiple-linear regression (MLR)-based model has been developed to estimate the reduction of the irrigation cost due to the elevation of the groundwater level. The application of the SVM model revealed that the groundwater level in the area can be kept within the suction lift of a shallow tube-well by reducing pre-monsoon groundwater-dependent irrigated agriculture by 40%. Adaptive measures, such as reducing the overuse of water for irrigation and rescheduling harvesting, can keep the minimum level of groundwater within the reach of shallow tube-wells by reducing only 10% of groundwater-based irrigated agriculture. The elevation of the groundwater level through those adaptive measures can reduce the irrigation cost by 2.07 × 10³ Bangladesh Taka (BDT) per hectare in Northwest Bangladesh, where the crop production cost is increasing due to the decline of the groundwater level. It is expected that the study would help in policy planning for the sustainable management of groundwater resources in the region.     

Comparative Assessment of New Design Criteria for Irrigation Improvement in Egypt

The Egyptian Ministry of Water Resources and Irrigation (MWRI) has expressed concern about the current high cost of the Irrigation Improvement Project (IIP) implemented in the “old lands” of the lower reaches of the Nile River. Because the IIP is financed through fees paid by the direct beneficiaries of the project, i.e., irrigation water users, these same Egyptian agricultural producers are especially sensitive to the higher than expected costs that the project has incurred to date. The objective of the current study is to evaluate whether this cost reduction is associated with any deficiency in irrigation performance. This Monitoring and Evaluation (M&;E) study aims to answer questions such as: Does reducing pump capacity and increased pump operation affect the farmers negatively? And, does the use of electricity instead of diesel fuel affect the farmers positively? Six indicators were used to compare new design criteria in the W10 and the IIP1 irrigation system designs, water savings, irrigation cost, irrigation time, night irrigation, and land savings. The W10 project design achieved the minimum actual operating cost per unit of area and per unit of water compared to the IIP1 project design on both Meet Yazied and El-Mesk Canals. The total cost per unit of area in the W10 project design is lower than IIP1 by 19.33% and 24.92% on the Meet Yazied and El-Mesk Canals, respectively. The total cost per unit of water in the W10 design is also lower than IIP1 on the Meet Yazied and El-Mesk Canals. Average irrigation time for rice and cotton crops cultivated in the W10 area are higher than average irrigation time for these crops cultivated in the IIP1 area for all locations on the Mesqa (head, middle and tail), because of increased pump operation in the W10 area (16 to 20 h d^???1). The number of irrigation events at the head of the Sefsafa Canal in the W10 area is higher than on the Meet Yazied and El-Mesk Canals in the IIP1 areas because of the increased pump operation in the W10 area.     

Investment in Irrigation Systems under Precipitation Uncertainty

Efficient agricultural water management is indispensable in meeting future food demands. The European Water Framework Directive promotes several measures such as the adoption of adequate water pricing mechanisms or the promotion of water-saving irrigation technologies. We apply a stochastic dynamic programming model (SDPM) to analyze a farmer??s optimal investment strategy to adopt a water-efficient drip irrigation system or a sprinkler irrigation system under uncertainty about future production conditions, i.e. about future precipitation patterns. We assess the optimal timing to invest into either irrigation system in the planning period 2010 to 2040. We then investigate how alternative policies, (a) irrigation water pricing, and (b) equipment subsidies for drip irrigation, affect the investment strategy. We perform the analysis for the semi-arid agricultural production region Marchfeld in Austria, and use data from the bio-physical process simulation model EPIC (Environmental Policy Integrated Climate) which takes into account site and management related characteristics as well as weather parameters from a statistical climate change model. We find that investment in drip irrigation is unlikely unless subsidies for equipment cost are granted. Also water prices do not increase the probability to adopt a drip irrigation system, but rather delay the timing to invest into either irrigation system.     

不同灌溉工作制度下的灌溉管网优化设计研究

采用基于人工神经网络的两级优化设计模型 ,对自压式灌溉管网进行优化设计 ,并分析了不同灌溉工作制度对管网投资的影响。研究表明 ,通过灌溉管网优化设计 ,可以得到不同灌溉工作制度下的管网投资最小的优化设计结果。与原始设计方案相比能够节约大量的投资 ,并可用于选择合理的灌溉工作制度。     

Feasibility Evaluation of Pressurized Irrigation in Canal Commands

India has one of the largest and most ambitious irrigation programme in the world with net irrigated area exceeding 47 million hectares. However, the overall project efficiency from the headwork to the farmer’s field has been quite low which leads to not only poor utilization of irrigation potential created at huge cost, but also aggravates the degradation of soil and water resources and thereby endangers the sustainability of agricultural production system. As the cost of creating additional irrigation potential in terms of financial, human and environmental aspects has increased tremendously, need of the hour is to increase the irrigation efficiency of existing projects and use saved water for irrigating new areas or meeting the demand of non-agricultural sector. The contribution of application efficiency to poor irrigation efficiency is quite high and therefore increasing application efficiency by a shift in application method from surface to pressurized system has potential of vastly improving irrigation efficiency. To evaluate feasibility of this concept, a pilot study was initiated at Water Technology Centre for Eastern Region, Bhubaneswar, on one outlet of a minor irrigation command. The system has been designed in such a way that it provides pipe conveyance and surface irrigation for rice cultivation during monsoon season and pressurized irrigation during post monsoon period through a hybrid system of sprinkler and drip with four outlets for sprinkler irrigating 2.8 ha area and two outlets for drip irrigating 1.9 ha area. The system is also capable of providing irrigation through drip to part of a command during summer for third crop using water stored in service reservoir after the canal is closed in first week of April. To take care of sediment in the canal water, there are three stages of filtration: first by hydrocyclone filter which filters heavy suspended materials viz. sand, silt, etc., then by the sand filter and finally by the screen filter. The filtration at three stages reduces the turbidity to the desired level. It has been found that three-stage filtration reduced the turbidity to two NTU which is within permissible limit. Considering the cost of water saved, a benefit-cost ratio of the system was found out to be 1.126. This B: C ratio can be further increased by increasing the productivity of the fish and papaya in service reservoir area and better crop management during summer season.     

浅井低压灌溉优化配套技术研究及应用

本文对已有的浅井工程进行抽水试验、灌溉试验，经过理论分析，推导出了单井低压管道输水灌溉系统的最21-优出水量、最佳降深、最佳扬程、经济管径及田间多孔软管配水计算方法，确定了浅井灌溉费用最小、效益最大的浅井低压灌溉优化配套技术。     

Improving the effectiveness of aid: an evaluation of prospective Mekong irrigation investments

Large irrigation systems seem to be the logical add-on investment to the hydropower projects which are being planned in the Mekong Basin. Economic evaluations of irrigation schemes to date have not considered environmental costs and uncertainties about utilization. Comparisons between economic returns and poverty alleviation benefits from irrigation and from investments in other sectors are also sparse. A benefit–cost analysis of prospective irrigation investments in Lao PDR considering all these factors found that farm-scale irrigation investments performed better than large-scale investments. The benefit–cost ratio and head-count poverty reduction from large-scale irrigation investment were also substantially lower than for education, road construction and agricultural research and development.     

A cost allocation approach for irrigation water in Upper Egypt

An approach for estimating irrigation water cost is presented and applied to Upper Egypt. Two cost models are used. The first model is to estimate the cost of irrigation water if controlled with a multi-purpose structure. The model is used in estimating the irrigation cost at the High Aswan Dam. The second model is to allocate the cost of irrigation structures and the cost of irrigation at the multi-purpose structures among the served areas. The two models are applied to estimate the cost of irrigation water at the different regions of Upper Egypt.     

An Assessment of the Impact of Participatory Irrigation Management in Sri Lanka

This paper presents the results of a study on the effects of participatory irrigation management in Sri Lanka. The study is based on the application of a methodology developed by the International Water Management Institute (IWMI) to assess the impact of irrigation management transfer on the performance of irrigated agriculture. Performance is measured from several perspectives: financial, irrigation management, and agricultural productivity levels. Piecewise linear regression models are fitted to compare trends in performance during the five-year period before transfer and five years after. The results show that there has been a significant drop in government's recurrent expenditure for irrigation over time. The decline is not confined to schemes where participatory management had been introduced but to other schemes as well. The cost of irrigation to farmers has remained the same before and after transfer. The analysis reveals that irrigation management transfer alone did not bring about significant improvements in the quality of irrigation or agricultural productivity levels. However, in schemes where both management transfer and physical rehabilitation had occurred, significant improvements in agricultural productivity were noted.     

The effect of reclaimed wastewater on the quality and growth of grapevines

The effect of the use of treated wastewater on the growth of cabernet sauvignon and merlot grapes from the Guadalupe Valley, Mexico was evaluated. Secondary advanced effluent was used to irrigate the grapevines at a rate of 66 L/vine/week. Wastewater quality results confirmed that all parameters complied with Mexican legislation for crop irrigation as well as reuse in activities in which the public would be in direct or indirect contact with the reclaimed water. Results showed that the number of leaves per shoot and the overall biomass increased in plants irrigated with wastewater and grape production per plant was 20% higher. The concentration of carbohydrates, organic acids and pH were similar in grapes from vines irrigated with wastewater to those irrigated with groundwater. Throughout the experiment, no fecal coliform bacteria were detected in the cultivated grapes. The wastewater caused an increase in the biomass of the grapevines and there was no presence of microbial indicators in the final product so a higher wine production could be achieved without an increase in health risk related problems. If 200 L/s of reclaimed wastewater would be returned to be used for grapevine irrigation in Valle de Guadalupe (the same amount that is currently being sent as drinking water to Ensenada), assuming an irrigation application of 6,000-7.500 m3/ha/year, approximately 837-1046 hectares (ha) of grapevines could be irrigated. Part of ongoing research includes an economical analysis of the best options for Ensenada and the Valle de Guadalupe in order to establish the optimum volume of water to be returned, the cost of its transportation, as well as the cost of irrigation.     

用边际分析法推求喷灌工程设计风速

本文研究了设计风速与喷灌工程费用和设计风速与喷灌均匀度，作物产量之间的关系，应用自然风速的统计分析资料推求设计风速对工程效益和费用的影响，从而提出了用边际分析理论推求最优设计风速的方法，最后通过实例验证了这一方法是切实可行的。     

Asymmetric Information on the Provision of Irrigation through a Public Infrastructure: The Case of the Peninsula of Santa Elena, Ecuador

This paper analyzes the problem of irrigation provision through a public infrastructure in an environment of Asymmetric Information (AI) in a dry area of Ecuador. Due to mismanagement of information and bad definition of goals by the government, a massive interest in acquiring communal lands started in the Peninsula of Santa Elena (PSE) after the government announced the construction plan of a large public irrigation system. During this process, information asymmetries regarding the potential of the irrigation system always prevailed in favor of land buyers. After eight years of functioning of the irrigation system, less than 20 percent of its capacity is in use. This leads to a situation in which the operation and maintenance of the canals is not appropriate, thus endangering sustainability of agriculture itself. This paper starts from the hypothesis that AI has an important impact over the observed pattern of land use and therefore irrigation in the PSE. Under the condition of AI for public goods with costly access, a test was conducted to determine which of the characteristics for an optimal allocation fits in the case of the PSE. Farmer's marginal cost of access to irrigation in connection with the concentration of the property of land by new landholders is considered the relevant informational variable. The most important result of this paper is that the presence of AI induces a scenario in which new landholders demand a smaller quantity of irrigation because of the high marginal costs of farming on big farm plots. A second important result suggests that subsidies to new landowners through the provision of irrigation appear to increase inequality with respect to peasant-commoners.     

开封市污水灌溉费用效益分析

利用开封市用水资料,计算了开封市区农业灌溉、市政用水、工业用水可利用的回用水量。由于污水的农业回用涉及到许多环境问题,因此根据开封市具体实例分析了污水的农业回用对灌区土壤中As、Pb含量、小麦品质、地下水水质和居民健康的影响。同时,运用费用效益基本理论,选择了市场价值法、影子工程法和人力资本法对灌溉带来的直接效益和间接效益进行了计算,并折算为单方水的效益。最后对比单方水灌溉费用,得到污水灌溉的单方水净效益,以此分析了开封市污水农业回用的费用效益。     

现代灌溉新技术旱作膜袋灌

通过对华北平原地区旱作大田作物田间灌溉方式的调查研究,发现传统的地面灌水方法存在着蒸发量大、深层渗漏多,水分利用效率低,田间灌水均匀度差等问题。为了提高旱作大田的水分利用效率,提出一种新的灌溉新技术——旱作膜袋灌,实现适时适量精细控制灌溉。通过试验研究,膜袋灌能够较好地提高大田作物的田间水分利用效率,避免沟灌、畦灌等传统地面灌水方法存在的棵间蒸发和深层渗漏,同时也能够解决滴灌、微润灌、喷灌等灌水方法易堵塞、系统复杂、田间工程量大和经济成本高等问题,对现代的高效节水农业具有重要的现实意义。     

灌区井灌效率研究

灌区灌溉采用井灌井排，开发利用地下水资源，不但能有效降低地下水位，防止土壤次生盐碱化，还可以通过井渠互补，使农作物得到适时灌溉。针对目前井灌工程效率低下的问题，通过抽水试验，经过理论分析，推导出了井灌低压管道输水灌溉系统的最优出水量、最佳扬程和经济管径计算方法，从而可提高机井灌溉效率。     

Rainwater Management for Smallholder Irrigation and it’s Impact on Crop Yields in Eastern India

A tank cum open dug well system suitable for plateau region of eastern India has been developed for providing reliable irrigation to croplands. The system comprises of a series of tanks with open dug wells in the recharge zone of the tank that reharvest back the seepage water. Thus, the rainwater remaining in the tank as well as partial seeped water is used for providing round the year full irrigation. This system was evaluated in field in Keonjhar district of Orissa of eastern India with six tanks and five wells in two drainage lines. The total command area of the system of six tanks and five wells in both drainage lines is 23 ha and the total irrigation potential is 44.5 ha. The total cost of the system is US $19,180 making the cost of irrigation resource creation as US $426 per ha which is much less than about $2,220 per ha for major and medium irrigation projects in the last decade of 20th century. The system increased the rice yields from 1.92 t ha^− 1 to a range of 2.25 to 3.8 t ha^− 1 depending upon the package of practices or the amount of inputs. The farmers went for crops in post-monsoon and summer season and the cropping intensity rose to 112% in the first year, 126% in the second year and 132% in the third year. The internal rate of return from the system was 13.4% at the present level of utilization, which is about 2.4% more than the prime-lending rate of Indian banks, and 3.4% more than the lending rate for agricultural purposes.     

Chance Constrained Optimal Design of Composite Channels Using Meta-Heuristic Techniques

Optimal design of irrigation channels has an important role in planning and management of irrigation projects. The input parameters used in design of irrigation channels are prone to uncertainty and may result in failure of channels. To improve the overall reliability and cost effectiveness, optimal design of composite channels is performed as a chance constrained problem in this study. The models are developed to minimize the total cost, while satisfying the specified probability of the channel capacity being greater than the design flow. The formulated model leads to a highly non-linear and non-convex optimization problem having multimodal behavior. In this paper, the usefulness of two meta-heuristic search algorithms such as Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) are investigated to obtain the optimal solutions. Two site specific cases of restricted top width and restricted flow depth are also analyzed. It is found that both the algorithms performing quite well in giving optimal solutions and handling the additional constraints.     

Economic valuation of reduction in nitrogen outflow from a paddy field area equipped with a recycling irrigation facility.

We estimated the reduction in nitrogen outflow load from a paddy field that had a recycling irrigation facility and, by using a replacement cost method, evaluated the economic effect of nitrogen removal by the paddy field during the irrigation period in the Yoshinuma region of Tsukuba City, Japan. The recycling ratio of outflow water (proportion of outflow reused) was 13.5%. The nitrogen (N) outflow load was reduced by about 45 kg ha(-1) by the N removal function of the paddy field and by about 39 kg ha(-1) by the recycling irrigation facility. The paddy field equipped with a recycling irrigation facility as an N removal facility was valued at 32.6 million Japanese yen (JPY) ha(-1) and 0.72 million JPY ha(-1) per year, which compare it with the construction and maintenance costs, respectively, of a water quality improvement facility. The recycling irrigation facility was costed at 17.3 million JPY ha(-1) for construction and 0.21 million JPY ha(-1) for maintenance per year. The cost for constructing and maintaining a recycling irrigation facility was 53% of the value of the paddy field area equipped with a recycling irrigation facility as an N removal facility.