灌溉水利用率影响因素的主成分分析--以漳河灌区为例

Impact Factors of Irrigation Water Use Efficiency Based on Principal Component Analysis,Case from Zhanghe Irrigation District

基于漳河灌区1973-2006年共34年的资料，采用首尾测算分析法计算灌溉水利用率，根据灌溉水利用率及其影响因素长系列数据，采用主成分分析法对灌溉水利用率各影响因素的影响规律和影响程度进行计算分析。结果表明：塘堰供水比例、渠道衬砌率、节水改造投资和节水灌溉面积比对灌溉水利用率有较大正贡献率，而中稻灌溉定额、水稻种植比具有较大的负贡献率；反映当地种植结构及管理情况的塘堰供水比和中稻净灌溉定额、反映节水工程状况的渠道衬砌率和节水灌溉面积比对灌溉水利用率的影响较大，而反映自然条件的生育期降雨量及参考作物蒸发蒸腾量影响较小；灌溉水利用率整体随时间有上升的趋势，并存在明显波动，但这种波动在逐步减小，即灌溉水利用率的变化逐渐趋于平稳。

Based on the data of Zhang He Irrigation District from 1973--2006, the irrigation water use efficiency（ IWUE） was calculated with the net irrigation water use and gross irrigation water use. According to the IWUE and its impact factors of different years, the impact laws and its degree of different factors which affect the IWUE were investigated with Principal Component Analysis. The results showed that the local water （pond） supply proportion, the lining rate of canal, the investment of water-saving transformation and the area ratio of water--saving irrigation have greater positive contribution rate to the IWUE, while rice irrigation quota and rice cultivation proportion have greater negative contribution rate; the local water supply proportion and the rice irrigation quota which reflect the cropping pattern and management level, and the lining rate of canal and the area ratio of water-saving irrigation which reflect the water--saving irrigation conditions have greatest impact on the IWUE, while natural factors, including rainfall in growth period and reference crop evapotranspiration, have litter impact; overall the IWUE is rising over time, and there is an obvious fluctuations, but this fluctuation has been gradually reduced, which means the change of IWUE is gradually stabilizing.