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地面灌田面行水流动的数值模拟及应用 被引量:3
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作者 刘洪禄 杨培岭 曾德超 《农业工程学报》 EI CAS CSCD 北大核心 1997年第3期71-75,共5页
根据我国地面灌现状提出极限灌水状态和最佳灌水状态及其灌水技术参数的概念。用Newton-Raphson法和Preisman法对畦灌田面行水流动的零惯性模型进行求解,实现畦灌田面行水流动模拟。在此基础上探讨了畦灌的行水... 根据我国地面灌现状提出极限灌水状态和最佳灌水状态及其灌水技术参数的概念。用Newton-Raphson法和Preisman法对畦灌田面行水流动的零惯性模型进行求解,实现畦灌田面行水流动模拟。在此基础上探讨了畦灌的行水、入渗机理。用计算机模拟试验方法建立极限灌水定额q0、L关系的数学模型,并研究灌水技术参数q0、L对极限灌水定额的影响,进而探讨了q0、L对灌溉系统性能的影响。给出了适宜的畦长L和单宽流量q0的确定方法。结合通县宋庄地区实际,给出了该地区冬小麦适宜畦幅规格与灌水技术参数。利用上述畦幅规格与灌水技术参数对冬小麦灌水,收到节水增产的效果。 展开更多
关键词 地面灌 模型 数值模拟 灌溉系统性能
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Analysis of Irrigation Systems Employing Comparative Performance Indicators: A Benchmark Study for National Irrigation and Communal Irrigation Systems in Cagayan River Basin
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作者 Jeoffrey Lloyd Reyes Bareng Orlando Florendo Balderama Lanie Alejandro Alejo 《Journal of Agricultural Science and Technology(A)》 2015年第5期325-335,共11页
Comparative performance analysis of four irrigation schemes within Cagayan River Basin was assessed using comparative performance indicators between the years 2008 and 2012. The objectives were to establish benchmarks... Comparative performance analysis of four irrigation schemes within Cagayan River Basin was assessed using comparative performance indicators between the years 2008 and 2012. The objectives were to establish benchmarks for both productivity and performance of irrigation schemes along the valley and to inquire whether small schemes function better than large schemes. The performance evaluation study of the systems composed of three general performance indicators, based on three domains-(1) system operation performance; (2) agricultural productivity and economics; (3) financial performance. Each indicator was assessed based on the prescribed descriptors used by the International Water Management Institute (IWMI) and Food and Agriculture Organization (FAO). Analysis showed an overall system performance efficiency of 59%, 55%, 47% and 36% for Magat River Integrated Irrigation System (MARI1S), Lucban, Garab and Divisoria Communal Irrigation Systems (CIS), respectively. In terms of annual productivity performance, Lucban CIS dominates the three other systems with 0.35 kg/m3, which was classified as moderately performing system, while the rest were classified with low productivity index. Financial sustainability of the systems were extremely poor with cost recovery ratio of 0, 0.33, 0.41 and 0.49 for Divisoria, Garab, Lucban and MARIIS, respectively, which were exceptionally below the standard value of at least one. Also, analysis of the indicators revealed that on average, large schemes performed similarly to small-scale schemes, but small schemes were more variable, particularly in input-use efficiency. The benchmarking study will provide strategic information to policy makers of agricultural and irrigation agencies on the existing weaknesses of irrigation systems in the country and determine in a more quantifiable terms levels of potential improvement and intervention targets. 展开更多
关键词 Communal and national irrigation systems performance benchmarking small and large reservoir schemes.
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