Calculation And Analysis Of Influencing Factors Of Effective Utilization Coefficient Of Farmland Irrigation Water In Jiangsu Province

Agricultural irrigation water consumption in China accounts for more than 60%of its total water consumption.Also,the effective utilization of irrigation water has implications on the sustainable development of water resources.Therefore,it is of great significance to study the calculation method and influencing factors of irrigation water utilization coefficients to utilize water resources more efficiently.In this study,Jiangsu Province was taken as an example to calculate the effective utilization coefficients of irrigation water in different scales,such as typical fields,sample irrigation areas and the whole province,by using the end-to-end calculation method.Based on the calculations,this study analyzes the factors that affect the effective utilization coefficients,and provides measures to improve them.The main results of the research are as follows:(1)Based on end-to-end measurement method,the calculation model of effective utilization coefficients of irrigation water is established,and each parameter in the model is determined.It mainly includes: annual gross irrigation water consumption,irrigated area,calculation method of net irrigation water consumption,net irrigation quota and annual net irrigation water consumption.(2)The effective utilization coefficient of irrigation water in the sample irrigation area in 2019 is 0.5811.According to the effective utilization coefficients of irrigation water in different scales and types of irrigation areas which are calculated based on the calculation results of sample irrigation areas.the irrigation coefficient of provincial large-scale irrigation areas is 0.5717,that of medium-sized irrigation area is 0.5816,and that of small-sized irrigation area is 0.6631.Finally,the effective utilization coefficient of irrigation water in Jiangsu Province is 0.614,and the empty data network is formed.(3)According to an analysis of factors influencing the effective utilization coefficients of irrigation water in terms of climate,water resources,soil,irrigation area scale,irrigation area type,project investment and management,there is a weak correlation between climate,water resources and coefficients;soil permeability and is negatively correlated with coefficients;the effective utilization coefficient of irrigation water in small-sized irrigation areas is higher than that in medium-sized irrigation areas and that in large-scale irrigation areas.The higher the project investment is,the more obvious the improved coefficients are;The higher-quality the management is,the higher the irrigation coefficients are.(4)According to the mathematical model established and evaluation of economic benefits of project investment by TOPSIS method,it is concluded that if there is limited amount of investment,more investment in large-scale irrigation areas can greatly improve the effective utilization coefficients of irrigation water;by analyzing three different irrigation modes in Qing ’an irrigation area,such as canal irrigation,low-pressure irrigation and micro-irrigation,it is concluded that if low-pressure irrigation is used in all areas,the water-saving potential of Qing ’an irrigation area will be 31.5067 million cubic meters;if micro-irrigation is used in all areas,the water-saving potential will be 49.8434 million cubic meters.After analyzing different irrigation methods,it is found that the water storage and controlled irrigation method saves 32.9 percent water than the conventional irrigation method.The water productivity of water storage and controlled irrigation method is obviously higher than that of conventional irrigation method.The irrigation amount of the conventional irrigation method in the test site is lower than that in the irrigation area in fields.The irrigation amount of the conventional irrigation method in the test site is 12.8% less than that in the irrigation area in typical fields.The measures to improve the effective utilization coefficients of farmland irrigation water in the province are put forward from the aspects of capital utilization,management measures,engineering measures,agronomic measures and water price measures.