Finite‐Element Modeling of Storm Water Runoff Using GRASS GIS

This paper presents methodologies used in the model r.water.fea for simulating storm water runoff using the finite-element method and a raster geographic information system (GIS). The internally integrated model r.water.fea simulates storm water runoff by interfacing the raster data structure with the finite-element solution of the kinematic wave equations. The integrated system offers many advantages because the GIS and simulation model exchange input and output data internally. Distributed simulation of the spatially and temporally variable hydrologic process is possible with r.water.fea. Storm water runoff simulated with r.water.fea compares favorably with analytic solutions for a simple domain. An example simulation of a catchment demonstrates the capabilities of r.water.fea.