水电能源科学

灌区排水是农业灌溉不可避免的伴生过程，普遍存在于我国西北地区的灌溉农田，由于水质较差，若重新退回河道，将对流域水生态环境造成威胁。为此，以杭锦旗黄河南岸灌区为例，构建了MIKE SHE分布式水文模型，模拟预测灌区排水量及可利用量，同时利用水均衡法、引排比法等方法与水文模型模拟结果进行交叉校核。结果表明，现状排水系统工况下，多年平均排水量4 821×10⁴m³,可利用量4 339×10⁴m³;排水系统提升改造后，多年平均排水量4 920×10⁴m³,可利用量4 428×10⁴m³。各方法排水量预测结果略有出入，但总体相差不大，MIKE SHE水文模型模拟结果与平均值偏差控制在±4%以内，而验证期模拟排水相对误差为3.7%,可见MIKE SHE水文模型在灌区排水过程模拟中效果较好，可为灌区排水资源化利用提供参考借鉴。

Irrigation drainage is an inevitable accompanying process in agricultural irrigation, widely present in the irrigated farmlands of the northwest region of China. Due to poor water quality, if it is returned to the river channels, it will pose a threat to the water ecological environment of the basin. Taking the Huanghe South Bank Irrigation District in Hangjin Banner as the research object, a MIKE SHE distributed hydrological model was established to predict the drainage volume and available volume of the irrigation district. Cross-checking was conducted with the simulation results of hydrological models by using the water equilibrium method and the ratio of diversion to drainage method. The results show that under the current drainage system conditions, the multi-year average drainage volume is 48.21 million m³, and the available volume is 43.39 million m³; After the drainage system is upgraded and transformed, the multi-year average drainage volume is 49.20 million m³, and the available volume is 44.28 million m³. The drainage volume prediction results of each method vary slightly, but the overall difference is not significant. The simulation results by MIKE SHE's hydrological model and the average deviation is controlled within ±4%, while the relative error of the simulated drainage during the verification period is 3.7%. The MIKE SHE hydrological model performs well in simulating the drainage process of the irrigation district, which can provide reference for the resource utilization of irrigation district drainage.