Development of a rainfall]runoff model for watershed]management systemiWMSj

Yoko TOMITA, Toshio MORI, Yoshiiku MUSASHI, Tomoyuki SUZUKI and Takahisa MIZUYAMA

The management of runoff and sediment discharge in a mountain watershed requires a watershed]management system(WMS)that predicts runoff and sediment discharge in any stream section under given rainfall conditions. As part of this system, a rainfall]runoff model was developed. As an example, the Sumiyoshi River on Mount Rokko was selected. So]called zero]order torrents were treated as channels to evaluate erosion and debris flow. In the system, multilayer intermediate flow is introduced to explain the observed flow discharge to avoid eliminating the initial rainfall loss.