地表径流与地下渗流耦合的水动力数学模型

Coupled hydrodynamic modelling of surface runoff and underground seepage

深入研究暴雨作用下地表径流与地下渗流过程,对山洪与滑坡灾害防治意义重大.然而,迄今为止对地表与地下水流的相互作用机制的理解还极为有限.基于地表完整一维浅水动力学方程与地下二维饱和-非饱和渗流方程,建立地表径流与地下渗流耦合水动力数学模型,并分别运用WAF-TVD二阶数值格式和ADI法进行离散求解.与现有实验数据比较,结果表明该模型能更好地模拟坡地的降雨产流和下渗过程.该计算模型具有健全的物理机制,将为深入研究地表-地下水流运动过程提供理论基础,有助于增强山洪与滑坡风险预测的可靠性.

Enhanced understanding of surface runoff and underground seepage in response to rainfall is crit- ical for flash flood and landslide risk management. However, the mechanism of the interaction between the surface and groundwater flows has so far remained poorly understood. This paper presents a coupled hy- drodynamic model for surface runoff and underground seepage. The complete one-dimensional shallow wa- ter dynamic equations and the two-dimensional saturated-unsaturated seepage equations are integrated, and numerically solved respectively by the second-order total-variation-diminishing version of the weighted-av- erage-flux method （WAF-TVD） and alternating direction implicit method （ADI）. Compared with available experimental data, this model can better simulate the rainfall runoff and infiltration processes over the slope. A physically based computational modelling system is facilitated for surface-ground water flows, which holds promise for flash flood and landslide risk forecasting with increased credibility.