内蒙古河套灌区灌溉入渗对地下水的补给规律及补给系数

为准确估计内蒙河套灌区灌溉水入渗补给地下水量，采用试验研究与数值模拟相结合的方法，分别根据灌水前后地下水位变化和土壤含水率变化计算了灌溉水入渗补给地下水系数，并依据土壤水动力学原理，采用数值模拟验证，得到作物生育期灌溉补给地下水系数为0.15，秋浇灌溉补给地下水系数为0.3。河套灌区地下水位埋深相对较浅，通过灌水前后的土壤含水率变化情况和数值模拟结果显示，灌水2～4 d补给地下水量达到最大，8～10 d后即完成对地下水的入渗补给，不同灌水量灌溉水入渗规律基本一致，入渗补给量和入渗时间与灌溉水量直接相关。研究结果将为确定维持灌区生态环境良性发展的引水量阈值提供参考。

Irrigation infiltration and recharge coefficient in Hetao irrigation district in Inner Mongolia

In order to accurately estimate the groundwater recharge due to irrigation deep percolation, the groundwater recharge coefficients were calculated based on changes of groundwater level and soil water content before and after water application jointly using field experiment method and numerical simulation method, and the results were verified using numerical simulation based on principles of soil water dynamics. The groundwater recharge coefficients were 0.15 and 0.3 for crop growth period and autumn respectively. With a shallow groundwater level in Hetao irrigation district, the results from change of groundwater and numerical simulation showed that the groundwater recharge reached maximum at 2-4 days after water application and groundwater recharge process completed at 8-10 days after water application. The deep percolations of different water applications followed the same pattern and the groundwater recharge and time were closely related to water application. The research results may provide a reference to the determination of threshold value of water diversion for sound development of ecological environment of the district.