Study On Diagnosis Of Irrigation District Operation Status And Its Regulation Mode

Agriculture,as our country’s primary industry,is an important foundation of the national economy.Due to its exceptional natural conditions,the temporal and spatial distributions of precipitation and water resources in China are extremely uneven,so it is imperative to vigorously develop irrigated agriculture.Irrigation district plays a decisive role in the process of China’s agricultural development.Since most of medium and large-sized irrigation districts were built in the1960s and 1970s.Limited by the economy and construction technology at that time,the engineering construction standards were low,the supporting facilities were not complete,and the maintenance and management were insufficient.This leads to the low efficiency of irrigation area,which could not adapt to the development of water-saving irrigation agriculture in the new period.Therefore,it is urgent to carry out evaluation of irrigation district operation status and optimization of its regulation mode.As an important grain production base in China,Heilongjiang Province has built the"ballast stone"for national food security.Although its grain production has achieved 17consecutive year of a bumper harvest,the water conservancy project construction in irrigation area and its supporting facilities are inadequate,which seriously affect the development of local water-saving irrigation agriculture.Based on this,this study selected 20 typical irrigation districts in Heilongjiang Province as the research base to carry out the evaluation of irrigation district operation and the research of regulation mode.The purpose of this study is to explore the optimal evaluation model of irrigation district operation,to reveal the driving mechanism of irrigation district operational status,and to formulate irrigation district operation status regulation program.The main research contents and results of this paper are as follows:(1)This paper established the evaluation index system referred to the evaluation index system of irrigation area developed by the Food and Agriculture Organization(FAO)of the United Nations and other relevant institutions,combined with the specific natural,cultural,and economic conditions of the studied area,and referring to relevant research literature of domestic and foreign experts and scholars.The index system for the evaluation of the operation status of the irrigation district was constructed with comprehensive evaluation of the irrigation area’s operation status as the target layer,the production efficiency,economic benefits,engineering status,system operation status,management level and ecological environment of irrigation area as the rule layer,and the index layer was composed of 37 indicators.Firstly,in the process of index screening,16 indicators with incomplete statistics and incalculable data or difficult to be quantified were deleted.Then,7indicators with large overlap of information were deleted by using the R cluster analysis and factor analysis.Finally,the coefficient of variation method was used to replace the irrigation satisfaction rate with lower discrete coefficient with water efficiency of irrigation,and deleted the soil p H value with low dispersion coefficient.A optimal set of evaluation indicators containing 10 indexes was established,and the evaluation index system for irrigation district operation was constructed.By analyzing the information contribution rate of the evaluation index set,it was proved that the result of index screening is reasonable and feasible.(2)This paper constructed a support vector machine model(SVM),a support vector machine model based on gravitational search algorithm(GSA-SVM),and a support vector machine model based on an effective modified gravitational search algorithm(MGSA-SVM)with adaptive hybrid random mutation mechanism.The model was used to evaluate the current operating status of the 20irrigation districts in the studied area,and obtained the operating status index and operating status rank of each irrigation area calculated by three model.Comparative analysis were conducted to the fitting performance indicators of four evaluation models,including mean absolute error(MAE),mean average percentage error(MAPE),coefficient of determination(R~2)and root mean square error(RMSE).The sequence-number summation theory and Spearman’s rank correlation coefficient method were used to analyze the stability of the model,and the differentiation theory was used to analyze the reliability of the model.MGSA-SVM was selected as the optimal evaluation model in the evaluation of irrigation operation.Based on the results of this evaluation model,the spatial evolution characteristics of irrigation operation were analyzed by Arc GIS spatial data analysis.(3)The principal component analysis was conducted to analyze the driving mechanism of the overall operation status of the studied area.The results showed that output value of facility control area,irrigation water utilization coefficient,income-to-expenditure ratio,revenue per unit of irrigation water consumption,and project matching rate are five key driving factors.The Decision-Making Trial and Evaluation Laboratory(DEMATEL)method was conducted to analyze the influential degree,influenced degree,cause degree and center degree of five key driving factors.The importance ranking of key driving factors,the cause driving factors and result driving factors of each irrigation area were revealed,and the driving mechanism of the driving factor of each irrigation area was explored.(4)The Huashuchuan Irrigation District and the Xiangmoshan Irrigation District were selected as the research objects.The scenario design method was adopted to build three different scenarios to simulate the irrigation area.Under the constraints of the scenario mode,an immune genetic algorithm channel section design optimization model was constructed.Based on the design theory,the optimization objective function is formulated,the constraint boundary is calibrated,the channel section optimization design is carried out for the Xiangmoshan Irrigation District and the Huashuchuan Irrigation District,the optimized plan is output,and the optimal plan is selected according to the proposed optimization target.The MGSA-SVM is used to evaluate the operation status of the irrigation area under different scenarios,and to compare and analyze the adjustment and optimization of the operation status of the irrigation area by the scenario simulation transformation.