Simulation of Sediment Disasters Due to Slope Failures and the Following Sediment Runoff

Abstract

While the sediment disasters in the mountain area usually occur as multi-modal type, most of the existing warning systems or disaster prevention plans only consider single hazard. This study integrates rainfall-infiltration, slope stability, water discharge, and sediment runoff model to simulate the multi-modal sediment disaster on a basin scale. The results indicate that river discharge and sediment runoff are obviously affected by rainfall pattern, and had significant contribution to the change of riverbed elevation. In addition, this study proposes a new warning indicator (Critical water content, Wcr), which is based on IRIS (the Integrated Rainfall-Infiltration-Slope stability) model and multiple regression analysis, for assessing slope stability. It can swiftly predict which slope and when it collapses on a basin scale. The results not only offer the verification of the disaster prevention plan but also provide the foundation of developing the multi-modal disaster warning system.