Integrated Benefit Evaluation Of Water Saving Improvement In Irrigation Districts And Reasonable Distribution Research Of Irrigation Water Resources

Study on the integrated benefit evaluation of water saving improvement in irrigation distracts (IDs) and the problem of associated regulation with surface water and groundwater is very necessary for guiding the after-evaluation of water saving improvement project and ensuring sustainable utilization of water resources in IDs. At present, there are a few research results about quantitative evaluation of integrated benefit from social, economic and ecologic environment at home and abroad. Therefore carrying out this research has very important theoretic value and real production significance.On the basis of referred to a great deal of literature and information and using the technical route combined with investigation analysis, model simulation, theoretic study and application of real examples, this paper come from the practice in Nine Irrigation Districts of Guanzhong in Shaanxi Province. In the first, analyzed the natural condition and existent major problems in IDs, from the point of view of sustainable utilization of water resources and ensuring the safety of food supplies in Shaanxi. discussed the urgency and importance for the water saving improvement in IDs. Second, combined with the execution of water saving improvement in IDs, using the fuzzy comprehensive evaluation method, established the integrated evaluating index system constituted by the eight indexes and five items as sociality, resource, economics, technique and ecologic environment. Composed the integrated evaluation model, the comment will be dividedfour grades as low benefit, general benefit, good benefit and very good benefit. By the fuzzy analysis and calculation, have obtained the integrated evaluation value, from the actual year 0.50 increasing to 0.66 of planning year, it explained that after water saving improvement, the integrated evaluating index upgrade a distinction, as from the genera! benefit to goo.d benefit. Third, considered the systems of society, economics and water resources, using the simulation technology, established the simulation model of optimal distribution combined surface water with groundwater. As Jinghuiqu ID for the example, has forecasted the irrigation requirements and the intake of river water source in near future (2005) and far future (2010), the irrigation requirements is 707 million m~3 and 694 million m~3, the intake of river water source is 1.483 billion m~3 and 1.467 billion m~3, and the water supply volume is 660 million m~3 and 653 million m~3 respectively. Moreover by the calculation of simulation model and balance analysis of water supply with irrigation requirements, obtained the conclusion that in the general drought year, the runoff in river source was rather abundant, the groundwater supply only account about 25% of the gross water supply, the groundwater source can be refilled; In drought year or special drought year, the groundwater supply account about 30%, the groundwater reservoir can be used for water volume adjustment, the groundwater complement major depend the surface water in rich water year and irrigation seepage water. So enhancing the united regulation of groundwater with surface water will be infected the water resources distribution in a bigger region, ensured sustainable utilization of the water resources in IDs.