基于SFA的灌溉水利用效率指标随时间变化规律分析

以湖北漳河灌区长系列数据为背景,采用随机前沿分析(SFA)对灌溉水利用系数(IWUE)及灌溉水分生产率(WP)的生产函数模型及技术无效模型进行参数估计和假设检验,结果显示后者的模型拟合较好.总体而言,IWUE的技术效率高于WP,但WP的技术效率增长幅度较大.技术无效参数估计结果表明,作物生育期降雨量对IWUE技术效率影响最敏感,其次是田间节水灌溉面积比,再次是水稻种植面积比和年均ET0;作物生育期降雨量、田间节水灌溉面积比、水稻种植比与WP技术效率的相关性比较显著.由于资料系列较短,年节水改造投入和渠道衬砌率对两个指标的技术效率影响不明显.

Temporal variation law of irrigation water use efficiency indicators based on stochastic frontier analysis

Based on the long time series data from Zhanghe Irrigation District,Hubei,China,this paper investigated the production function model and technical non-efficiency model of irrigation water use efficiency(IWUE) and irrigation water productivity(WP) besed on stochastic frontier analysis(SFA) methods.The estimated parameters and assumptions test result show that WP model has a stronger explaination than that of IWUE.As a whole,technical efficiency of IWUE is higher than that of WP;but technical efficiency of WP has a big increasing ratio than that of IWUE.The estimated parameters of the non-validity indicate that the rainfall has greatest influence on IWUE;and the second is ratio of adopting water-saving irrigation area;the third is ratio of rice cultivation and annual ET0.Rainfall in cropping season,ratio of adopting water-saving irrigation area and ratio of rice cultivation shown the significant pertinency with the technical efficiency of WP.Annual investment of rehabilitation & reconstruction and ratio of canal linning have no significant influence on the technical efficiency of IWUE and WP because their data series is too short.