Development and Verifying of Calculation Method of Standard Rainfall on Warning and Evacuation for Forest Soil Sediment Disaster in Mountainous Area by Using Tank Model

摘要

This study was conducted to develope calculation method of standard rainfall, which was used for predicting the outbreaking time of disaster by using, Tank model, on warning and evacuation for soil sediment disaster. We investigate adeption possibility of developed method through comparing storage function method with Tank model. We calculated storage amount rainfall by storage Function method and Tank model with 36 hillslope failures which have record on outbreaking time of disaster. The result in case of Sedimentary (quarternary period) showed that the difference of outbreaking time was 1.6 hour in case of tank model, but 3.2 hour in case of storage function method. In addition, the deviation of the peak storage were 7% in case of tank model, but 63% in case of storage function method. Total evacuation period was analyzed by using observed 5 years (1993-1997) rainfall data as well as each standard rainfalls which were determinated by two methods. The result showed that evacuation time by storage function method was about twice as man), as that by tank model. Therefore, we concluded that calculation by tank model for predicting the outbreaking, time of disaster was more useful and accurate than storage function method.