A 2-D and 3-D Composite Dimensional Fully Coupled Surface and Subsurface Flow Model

概要

論文の詳細を見る
To numerically analyze the hydraulic and hydrological aspects of water environment in an alluvial area that has three-dimensional (3-D) complexity in its geological structure, a composite dimensional physically-based numerical model is developed by use of the finite volume method (FVM). The model consists of the surface and subsurface flow submodels which are based on the 2-D shallow water equations of diffusion type, and the 3-D mixed-form Richards equation, respectively, and fully coupled. The FVM-based numerical formulation and the use of the pentahedral cell with a triangular-shaped top face for piecewise discretization are of great advantage in economizing the computational tasks while finely resolving the land surface, say, on a field-plot-scale resolution. The example application of the model developed is made to an actual area embracing the hillside as well as the alluvial fan where paddy rice farming is implemented, aiming at holistically and heuristically surmising whether the multiple clayey layers of the subsurface stratum are perfectly or imperfectly compacted with clayey soils. The result shows that the model has capabilities as a helpful tool for simulating the interlinked surface and subsurface flows in an alluvial farmland area expanding over the subsurface stratum of 3-D complexity.
日本雨水資源化システム学会の論文