中文摘要：

根据质量守恒原理,建立了包气带和含水层的水盐均衡模型,并对宁夏银北各干渠灌域的土壤含盐量、地下水埋深和地下水矿化度的变化过程进行了模拟.在含水层水量均衡方程中,把潜水蒸发系数和给水度作为变参处理,考虑了相邻灌域间的潜流交换量.针对方程的非线性性质,提出了迭代求解方法.含水层盐量均衡方程中潜流的携盐量视其交换方向而定,与包气带盐量均衡方程联立构成方程组后,利用共轭梯度法求解.预测结果与实测数据对比表明,相对误差在8%以内,该模型可用于银北灌区的水盐动态预测.

英文摘要：

According to the principle of mass conservation, water and salt balance models for aeration zones and aquifers were established and employed to simulate the variation of soil salt content, groundwater depth and mineralization in the irrigation areas of each canal in the Yinbei irrigation district of Ningxia. In the water balance equation for aquifers, the evaporation coefficient and the specific yield of phreatie water were treated as the variable parameters, and the subsurface exchange flows between the adjacent irrigation areas were considered. An iteration method was proposed with regard to the nonlinearity of the equation. In the salt balance equation for aquifers, the amount of salt carried by the subsurface flows was determined based on their exchange directions. The simultaneous equations of the salt balance between the aquifers and the aeration zones were solved with the conjugate gradient method. Comparison between the simulated results and measured data shows that the relative error is smaller than 8 %, and the present models can be applied to the prediction of the water and salt variation the Yinbei irrigation district.