| Large-sized irrigation district has been playing a vital role in China national economicdevelopment and agricultural production. Large-sized irrigation district is an importantfacility to guarantee our food security and it is considered to be an important productionbase of agriculture large scale production and commodity of grain, cotton and edible oil inChina. For improving grain yield and comprehensive agricultural production capacitylarge-sized irrigation district has its own advantage. Large-sized irrigation district is also acollection of the society, environment and all the activities of irrigation districts. Thestatehas been attaching great importance to the construction of large-sized irrigation district andrelease Central Document focus on accelerating continued construction and water-savingtransformation for large-sized irrigation district. At this stage, the large-sized irrigationdistrict modernizationis an important part of agriculture modernization.Through readinglarge numbers of information home and abroad,combines with the improvement practice ofthe large-scale irrigation district,by the technical route of linking theory with instancesanalysis,the main achieves are as following:(1) Partition of the scale of the large-sized irrigation and classification. The scale ofthe large-sized irrigation district varies greatly. On the basis of the hierarchical clusteringmethod using fast clustering (K-means) method and combination with the practicalsituation of the large-scale irrigation district,the scale of the large-sized irrigation districtwasdivided into four levels. China is large in area and covers different kinds of landforms,according to the natural conditions, agricultural production conditions and irrigationcharacteristics of the large-sized irrigation district, six major areas are divided thelarge-sized irrigation district.(2) Composition structural analysis of the large-sized irrigation district.Analyze thetype of the headwaters project, irrigation canal, irrigation and drainage combined canal,drainage ditch and management situation of the large-scale irrigation according to the scalelevel and geographical area division involving drainage (ditch) channel length per unitirrigated area, lining length ratio of the irrigation canal, canal (groove) structures quantityper unit, faculty quantity per unit area, group organization management area and other impact factors.(3) The farmland effective irrigated area of the large-sized irrigation districts has beenanalyzed The development trend of farmland effective irrigated area of large-sizedirrigation district from1978to2011was analyzed in this paper. The GM (1,1) model basedon the Markov chain was applied to forecast farmland effective irrigated area of large-sizedirrigation district from2013to2020.(4) Modernization evaluation index system of large-sized irrigation districts wasestablished.The main evaluation index of the modernization level for large-scale irrigationdistrict is summarized and the index is screened through the expert argumentation to meetthe large-sized irrigation district satisfaction. Evaluation system has been built consist oftwo level indexes.1st level index contains five subsystems: comprehensive characteristicof environment and society, engineering, benefits, management, ecology.2nd level indexcontains21indexes which was calculated on the index nature, calculation method, modelsand quantitative methods.Four assessment ratings are established in accordance.(5)Modernization evaluation method and application of large-sized irrigationdistricts.Evaluation objects are obtained from typical irrigation districts for each majorarea based on variable fuzzy sets. For each Evaluation object modernization level is ratedusing the assessment methods. Modernization level for typical irrigation districts in2011israted and finds the weak links. |
