A Simulation of Surface Runoff and Infiltration due to Torrential Rainfall Based on Field Monitoring Results at a Slope Comprising Weathered Granite

Abstract

The frequency of rainfall-triggered slope failure has recently been increasing in Asian countries. One plausible reason for the increased frequency is climate change. It is therefore a pressing issue to clarify the mechanism of infiltration, causing slope failure. From such a viewpoint, this study investigated the relationship of the runoff, the infiltration and the surface retention due to torrential rainfall by means of one-dimensional tank model analysis using the results of field measurement conducted in Phuket, Thailand. The results showed that the infiltration is temporally retained by the surface retention at the beginning of rainfall, including immediately after and that the time rate of the infiltration is affected by the rainfall intensity. Furthermore, this study investigated the applicability of the proposed method, which deals with the infiltration simulated by one-dimensional tank model analysis, by comparing with the measured values and the results of conventional method.