中文摘要：

基于我国西北干旱区石羊河流域复杂层状土条件下进行的混凝土衬砌渠道渗漏试验，建立了考虑混凝土衬砌层和层状渠床的饱和一非饱和有压土壤水入渗模型。采用HYDRUS-2D对渠道渗漏和土壤水分分布进行了数值模拟研究。模型模拟结果和实测渗漏量、实测渠道周边土壤含水率等吻合较好，表明该模型对于模拟复杂层状渠床情况下的渠道渗漏比较可靠。在此基础上，进一步模拟分析了渠道衬砌和土壤层状结构特性对渠道渗漏产生的影响，以及层状土和均质土在湿润峰行进方面的区别。结果表明渠道渗漏强度受渠道衬砌形式的影响最大，其次为渠床附近的弱渗透性土层，而层状渠床下强渗透性土层具有一定的减渗作用；均质土和层状土在渠道渗漏量相近情况下，土壤水分分布具有较大不同。

英文摘要：

Based on the canal seepage ponding test in the Shiyang River basin in northwest China, a saturated-unsaturated flow model with pressure infiltration was established for canal seepage with concrete lining and distinct layered canal bed. The HYDRUS-2D was applied for the simulation of canal seepage and the induced soil water content variation. The simulation results agree well with the data of monitored canal seepage and the soil water content variation, which indicates that the model is reliable for the canal seepage simulation under the complex soil structure. In addition, further simulations were carried out to examine the effect of canal lining and soil characteristics in soil layers on canal seepage, and to compare the difference of wetting advancement for layered soil and homogeneous soil. The results show that canal seepage is greatly influenced by the canal lining, followed by the soil layer near the bank with weak permeability. However, the soil layer with strong permeability tends to inhibit canal seepage to some extent. Under similar canal seepage rate, the soil water dynamics with layered soil can be significantly different from that of homogeneous soil.