DISTRIBUTED RAINFALL-RUNOFF MODELING APPLICATION FOR THE URBANIZED CATCHMENT

摘要

The distributed model, Vflow~TM, was applied to compute flood hydrographs from two major storms in a 299-km~2 urbanized catchment. The input parameters were prepared from a land use map, a soil map, and a digital elevation model. Calibration efforts were focused on infiltration parameters including saturated hydraulic conductivity and initial saturation, and on timing of peak discharges including channel slope and roughness. Two different methods for precipitation grid generation, the IDW (Inverse Distance Weighted) and the Thiessen weighting, were compared and the so-called 'tent pole effect' was clearly identified for sparse-density gage network. In terms of computing peaks and their timing of flood hydrographs, the overall performance of the distributed model, Vflow~(TM), seems to be quite impressive except relatively big discrepancy on the falling limbs which might be attributable to the interflow.