不同灌溉水分生产率指标的时空变异与相关关系

选择灌溉系统中的不同灌水量作为投入,建立毛灌溉水分生产率(Pg)、渠系灌溉水分生产率(Pc)及净灌溉水分生产率(Pn)指标;收集全国443个主要灌区1998年、2005年及2010年的数据资料,分析了中国灌溉水分生产的时空变化规律及指标间的相关关系。结果显示:3个指标的全国均值分别为1.361、2.532及2.989 kg/m3;各省区的3个指标均随时间呈增加态势,直辖市的增幅较大而长江流域粮食主产区较小;代表年各灌溉水分生产率指标在空间上均表现为明显的聚集现象,高值省区以黄淮海平原为核心集中分布,华南、西北及东北则密集了低值省区;Pg、Pc及Pn两两之间均呈现显著的线性相关关系,决定系数均大于0.90。3个指标中的任一指标均可代表省区灌溉水分生产率在全国的排序位置。

Spatial and Temporal Variation of Three Irrigation Water Productivity Indexes in China

Three indexes, gross irrigation water productivity (Pg), canal irrigation water productivity (Pc), and net irrigation water productivity (Pn), were built. The data from 443 major irrigation areas throughout China were collected in 1998, 2005 and 2010, and the spatial and temporal variation of irrigation water production and the relationship between the indexes were analyzed. The results showed that the national average value of the three indexes were 1.361, 2.532 and 2.989kg/m3. and the indexes in each province showed a trend of increasing with time. The municipalities directly under the central government increased large while grain producing areas in Yangtze River Basin were small. The irrigation water productivity indexes in representative years aggregated obviously in the area of Huang-Huai-Hai plain as a high value area while the low value areas were in south, northwest and northeast of China. There were significant linear correlations among Pg, Pc and Pn, respectively. The determination coefficients were greater than 0.90. Any index can be used as the representative of regional irrigation water productivity in the country.