表面流, 飽和・不飽和地中流相互干渉機構の分析モデル

Abstract

It has been recognized that surface flow and subsurface flow interact with one another inhillslope hydrologic processes. However, in most of runoff models, the interaction has beencompletely neglected or only conceptually taken into consideration. The aim of this paper is tocombine a two-dimensional saturated-unsaturated subsurface flow model with a one-dimensionaloverland flow model to form a coupled model and to try to elucidate the hillslope hydrologicprocesses with it. The mathematic model is solved by the Galerkin Finite Element Method. It isvery unique that surface flow and subsurface flow are treated as a simultaneous system. Withthe coupled model, we simulate the influences of soil hydraulic properties, rainflux and hillslopegeometry to runoff characteristics. By the simulation, it becomes clear that return flow plays agreat part in the interaction between surface flow and subsurface flow.