中文摘要：

随着节水灌溉尺度效应的深入研究,灌溉回归水重复利用被认为是导致农业用水效率尺度效应的重要因素之一。传统的基于田间试验或统计得到的单位面积灌溉用水量指标并未考虑回归水的重复利用。针对这一问题,考虑灌区管理部门干支渠灌溉系统管理的实际需求,分析了中等尺度区域灌溉回归水重复利用过程,首次提出了农业用水效率考核新指标“千公顷灌溉取水量”的概念,给出了相应的计算依据、方法及适用条件。经湖北省漳河灌区千公顷典型区域水平衡试验观测与模拟模型计算,论证了回归水利用在提高农业用水效率中的重要作用,表明“千公顷灌溉取水量”作为我国中等尺度区域特别是南方长藤结瓜灌溉系统农业用水效率考核指标,是必要和可行的。

英文摘要：

With the further research of scale effect of water saving irrigation, the use of return flow is con- sidered to be one of the important reasons of scale effect of agriculture water use efficiency. The water con- sumption of irrigation per unit area, which is based on the traditional experiments or statistics at field scale, does not take into account the use of return flow. Considering the actual management requirement of the irrigation department in the main canal and branch canal irrigation system, the process of the use of re- turn flow was analyzed in a middle scale district to this problem. A new index was proposed to evaluate the agriculture water use efficiency, which was called irrigation water withdrawal per 103 hm2. The calculation basis, method and application condition were also introduced. The water balance experiments and model calculation in a 103 hm2 district, Zhanghe Irrigation System （ZIS） in Hubei province, proved that the use of return flow played an important role in improving agriculture water use efficiency. And it also proved that it was necessary and practicable to apply the new index to agriculture water use efficiency evaluation, especially in the middle scale district with the conjunctive use of ponds and canals in southern China.