应用MODFLOW和LAK3计算水库渗漏量

Calculation of reservoir leakage based on MODFLOW and LAK3

在计算水库渗漏量时,常规的方法是根据水库水位观测成果反推水库的渗漏量。本文提出应用MODFLOW和LAK3模拟水库渗漏动态过程的方法,其基本原理是将达西公式和水均衡法相结合,由初始水位条件迭代计算下一时刻的水位和渗漏量,因此与常规计算方法具有本质的区别。以某拟建水库为例,通过变水头渗透试验获取库底地层渗透系数,应用MODFLOW和LAK3建立水库与地下水流耦合模型,模拟得到水库水位动态变化过程,并根据水量平衡方程计算得到水库年渗漏量为23万m3,占总库容的0.8%,水库水量损失以蒸发为主。

The conventional method of leakage calculation is based on water level observations. The approach of modeling reservoir leakage using MODFLOW and LAK3 is proposed in this paper which combined Darcy＇ s law and water balance principal to calculate the water level and leakage in the next time according to the initial value via iteration. It is different from the conventional methods essentially. Taking a planning reservoir project as example, the hydraulic conductivity of the aquifer is acquired by variable head permeability test, the model coupling reservoir and groundwater is built based on MODFLOW and LAK3. the modeling results show the dynamic process of the water level and the annual leakage is 2.3 × 10^5 m3 , accounting for 0.8% of total reservoir storage. The water loss is mainly caused by evaporation.