中文摘要：

基于改进SWAT模型，以漳河灌区为背号，模拟分析了不同情景下蒸散发及排水比的变化，并进一步分析灌区节水潜力。结果表明，水田蒸散发由大到小为淹灌、间歇灌溉和薄浅湿晒。基于蒸散发消耗调控，研究区现状条件下理论节水率为14．5％．远大于实际节水潜力；与淹灌相比，间歇灌溉和薄浅湿晒节水率分别为1．6％和2．4％。基于排水重复利用，研究区现状条件下理论节水率为16％；塘堰汇流面积比例从现状的30％提高到50％，排水管理节水率及实际灌溉节水率分别为3．8％和1％，而传统的灌溉取水节水率为19．9％；可见，不同计算方法得到的节水潜力存在很大差异。

英文摘要：

The changes of evaportranspiration （ET） and drainage fraction under different scenarios in Zhanghe Irrigation District were analyzed based on modified SWAT model, and water-saving potential was discussed further. Results showed ET of paddy field under different irrigation modes in decreasing order was as follow： continues flooding, intermit irrigation, shallow wet and dry. According to the regulation of ET, the theoretical water-saving rate in current situation was 14. 5~, which was far higher than actual water-saving potential ~ Compared with continues flooding, water saving rates were 1.6~, 2.4~ under in- termit irrigation and irrigation mode of shallow wet and dry. Using drainage reuse technique, theoretical water-saving rate was 16~ in current situation~ When the area ratio between pond and watershed catch- ment area increased from 30 ~ to 50 ~, water-saving rate based on drainage was 3.8 % and actual water- saving rate was only 1 ~, while water-saving rate by traditional way was 19.9 ~ ~ so water-saving potential calculated by different methods could lead to vast differences.