Runout of rainfall-induced landslides in Malaysia

One of the critical components in landslide hazard and risk assessment is the reliable estimate of the runout distance of the sliding mass. In Malaysia, the landslide risk management is in its early stages. However, despite these endeavours the current efforts remain insufficient. A new empirical method for runout estimation in Malaysia is introduced in this paper. This method adopted a similar form of empirical equation developed by previous developed methods but with application and adaption to the historical landslide data in Malaysia. Data on landslide events in Malaysia were collected, processed and analysed in order to discuss the correlation and significance of various influential parameters on the travel distance and to establish its prediction method. The performance of the newly developed methods was evaluated using assessment indices including the coefficient of determination (R2), mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute error (MAE), showing a close correspondence between the predicted and actual runout values. Therefore, this new method has practical potential not only in Malaysia but also in other tropical regions that share similar soil characteristics and climatic conditions. In addition, this method addresses the understudied yet influential parameter governing landslide travel distance, i.e. retrogression distance, thereby enhancing the accuracy of landslide prediction in Malaysia.