EFFECT EVALUATION OF DEBRIS FLOW COUNTERMEASURES WITH KANAKO (CASE STUDY ON HONGQIAO GULLY, CHINA)

Abstract

Debris flow is a natural disaster common in mountainous areas in Japan and China. It has great destructive force because of its high density and speed, and often causes great losses to human life and the economy. Therefore, countermeasures such as sabo facilities are very essential to reduce the damages. In this study, we applied GUI equipped debris flow simulator KANAKO to evaluate the effects of the debris flow countermeasures in Hongqiao Gully, Sichuan Province, China. The results show that the full dams which were constructed in 2001 still have the function for controlling debris flow to a certain degree. Because the trapped debris flow materials decrease the gully bed slope, and debris flow velocity decreases consequently. Through the comprehensive control of debris flow including trapping, drainage and deposition works, the simulation results indicate that the effects of the countermeasures in 2001 and 2006 are very good. The countermeasures can ensure residents’ life and property on the alluvial fan.