干旱区生态环境知识资源中心

Canal seepage is the major loss of irrigation water conveyance. It is also the main resource for groundwater recharge to the groundwater and thus helps to maintain the vulnerable ecology environment in the arid area. Therefore it is crucial to investigate quantitatively the pattern of canal seepage, and the induced groundwater response, for water resources evaluation and the groundwater protection. Based on a field experiment in North China, with monitored groundwater table fluctuation along the canal during water conveyance, we carried out the accordant simulation by HYDRUS-2D, which is a 2D simulation software capable of the simulation of saturated-unsaturated flow. The simulated groundwater table fluctuation and the seepage rate at different conveyance stages agreed well with the monitored data from field experiment. Based on the calibrated model, the canal seepage and its proportion for groundwater recharge were evaluated with main influencing factors, e.g., different groundwater levels, different soil texture under the canal bed. Results show that groundwater level and soil texture are important factors that influence canal seepage and its recharge to groundwater.