Study On Indexes Weights' Determination And Comprehensive Evaluation Method Of Water-Saving And Improvement Project's Post-Evaluation In Large-Scale Irrigation Districts

the author consulted lots of reference home and abroad, combining with the practical situation of nine large-scale irrigation districts' water-saving and improvement project in shaanxi GuanZhong area, by the technique route of linking theory with instances analysis,indexe weights' determination and comprehensive method of water-saving and improvement project's post-evaluation in large-scale irrigatin districts were studied, main achievements are as follows:(1) Aiming to the defects of common subjective weighting method and objective weighting method, the combination weighting method combining subjective and objective factor was applied to post-evaluation of irrigation districts'water-saving and improvement project, the application of three diffrent kinds of combination weighting method were comparatively studied, they are combination weighting method basing on units of constraints and combination weighting method basing on game theory and combination weighting method basing on sum of deviation square, the result show, weight vector's sort sizes getted by using three kinds of combination weighting method are not same,sort size of several irrigation districts' comprehensive evaluation values calculated by using three kinds of weight value are not same, this is caused by different principles of three kinds of combination weighting method, in practice using, different combination weighting method could be selected according to actual needs.(2) Further study on evaluation method was made basing on the present evaluation methods, two kinds of evaluating ideas including static and dynamic method were put forward, hierarchical comprehensive evaluation method basing scatter-degree is selected in static method, vertical scatter-degree method and vertical and horizontal scatter-degree method and timing operator weighted average method are selected in dynamic method.(3) Hierarchical comprehensive evaluation method basing on scatter-degree was applied to evaluation on irrigation districts' water saving and improvement project aiming to the defect that several irrigation districts' evaluation value are close or same and difficult to be distinguished when using common static evaluating method, index's weights were determined twice during calculation process, through which, indexes'combination weights were determined scientificly and reasonably, evaluation value is easy to be distinguished too. application result show, not only several irrigation districts' water saving and improvement project could be generally evaluated and distinguished, but also each level goal of different irrigation district water saving and improvement project could be getted and distinguished, thus multi-irrigation districts could be evaluated comprehensivly, systematically and detailedly.(4) In order to dynamically evaluate one irrigation district's water-saving and improvement project during several years, vertical scatter degree method were applied to irrigation districts' water-saving and improvement project's evaluation, taking jinghuiqu irrigation district's project during 2002 to 2005 for example, the result show that vertical scatter degree method could dynamically evaluate and distinguish one irrigation district's each year's water-saving and improvement project during several consecutive years, the calculation effort is small, has better application value.(5) In order to dynamically evaluate and distinguish several irrigation districts' water-saving and improvement projects on vertical and horizontal direction during consecutive years, vertical and horizontal scatter degree method was applied to irrigation districts' water-saving and improvement project's evaluation, take guanzhong nine irrigation districts' ecological environmental benefits evaluation for example, the result show that every year's evaluation result of several irrigation districts could be directly compared and evaluation results degree be scattered by using this method.not only the calculation effort is decreased but also irrigation district's different time's evaluation value could be compared directly by using vertical and horizontal scatter degree method.(6) In order to generally evaluate irrigation districts' water-saving and improvement project during consecutive years, dynamically evaluation was conducted by using "timing weighted average operator" method, this method is the introduction of "time weight vector entropy" and "time-degree" theory, the importance of each year was taken into account as much as possible by virtue of "time weight vector entropy", and the importance of timing was reflected by virtue of "time degree"λ, the optimization model was established basing on above theory, solving the optimization model could get each year's weight, consecutive years dynamic comprehensive evaluation value could be getted basing time weight vector value and annual comprehensive evaluation value. through nine irrigations'water-saving and improvement project's calculation result during four consective years from 2002 to 2005, then find that time factor have been taken into account and the results getted by using timing weighted average operator is more comprehensive, scientific and reasonable than the static results.(7) Aimin to the non-linear character of irrigation districts, the ecological footprints method were applied to evaluation on irrigation districts' water-saving and improvement project, water-saving and improvement project was evaluatd by calculating the change of ecological-deficit pre and post project's implementation, the impact on irrigation districts' ecological caused by water-saving and improvement projects was analyzed.