丘陵山地流域モデルと洪水流出モデル

Abstract

Several fundamental problems in applying the kinematic runoff models such as the interflowmodel, the overland flow model and the composite model to flood runoff analysis are studied bydealing with the data in the Shimokari hilly watershed of 1.3 km2, the 93% area of which is coveredby bushes and bamboo groves. First, a detail watershed model composed of 62 blocks or 136 blocksis constructed. The model is then lumped considering the stream order based on both Strahlerand N1 systems for ordering. The geomorphological characterisitcs of these models are examinedfrom the hydrological viewpoint. Second, the applicabilities of the kinematic runoff models areexamined by searching their optimum model parameters in every watershed model. And thepractical formulae have been proposed for estimating the optimum model parameters. Third, aninstantaneous unit hydrograph is proposed theoretically considering the interflow model and theprobability distribution of slope lengths.