Application of surface-subsurface flow coupled with numerical simulator torunoff analysis in an actual field

A numerical simulator that treats three dimensional, multiphase, surface-su bsurface combined flows was applied to actual runoff analysis. A sensitivit y study of hydraulic surface/subsurface interaction parameters required in numerical simulation was carried out utilizing short-term data, and a set o f parameters that reproduces an actual hydrograph was obtained. To improve reproducibility of the hydrograph, a modification of discretization in expr essing riverbed was introduced, so that a more realistic hydrograph is repr oduced and a better quantitative estimation about base and side flow is rea lized. Applying the result of the sensitivity study to long-term runoff ana lysis, the hydrograph in one year was reproduced satisfactorily with the sa me hydraulic parameters obtained in the short-term runoff analysis. Copyrig ht (C) 2000 John Wiley & Sons, Ltd.