A coupled surface/subsurface flow model accounting for air entrapment and air pressure counterflow
A coupled surface/subsurface flow model accounting for air entrapment and air pressure counterflow
复制标题
DOI：
10.1007/s12665-013-2420-1
复制
发表时间：
2013-04
影响因子：
2.8
通讯作者：
J. Delfs;Wenqing Wang;T. Kalbacher;Ashok Singh;O. Kolditz
中科院分区：
文献类型：
--
作者：
J. Delfs;Wenqing Wang;T. Kalbacher;Ashok Singh;O. Kolditz
本文将土壤-空气系统引入综合水文学中，模拟地表径流、土壤水分和空气在浅层地下的流动过程和相互作用。数值模型被制定为一个耦合系统的流体静力学（扩散波）浅水流和两相流在多孔介质中的偏微分方程。土壤，陆上，和大气舱之间的同时传质是通过升级一个完全建立的泄漏概念陆上土壤液体交换到土壤和大气之间的空气交换通量。在一个新的算法中，泄漏操作作为一个阀门的气体压力在液体覆盖的多孔介质，促进模拟空气爆发事件通过陆地表面。一般的标准，以保证稳定的顺序迭代耦合算法，此外，泄漏控制室之间的质量交换。一个基准测试，这是基于一个经典的实验数据集上的渗透过量（霍顿）坡面流，确定了地表径流和土壤气压之间的反馈机制。我们的研究表明，在特定地点，特别是在近流地区，土壤中的空气压缩放大了高降水期间的地表径流。
This work introduces the soil air system into integrated hydrology by simulating the flow processes and interactions of surface runoff, soil moisture and air in the shallow subsurface. The numerical model is formulated as a coupled system of partial differential equations for hydrostatic (diffusive wave) shallow flow and two-phase flow in a porous medium. The simultaneous mass transfer between the soil, overland, and atmosphere compartments is achieved by upgrading a fully established leakance concept for overland-soil liquid exchange to an air exchange flux between soil and atmosphere. In a new algorithm, leakances operate as a valve for gas pressure in a liquid-covered porous medium facilitating the simulation of air out-break events through the land surface. General criteria are stated to guarantee stability in a sequential iterative coupling algorithm and, in addition, for leakances to control the mass exchange between compartments. A benchmark test, which is based on a classic experimental data set on infiltration excess (Horton) overland flow, identified a feedback mechanism between surface runoff and soil air pressures. Our study suggests that air compression in soils amplifies surface runoff during high precipitation at specific sites, particularly in near-stream areas.