Quantitative hazard analysis for landslides in Hulu Kelang area, Malaysia

Abstract

Hulu Kelang is a region in Malaysia which is very susceptible to landslides. From 1990 to 2011, a total of 28 major landslide events had been reported in this area. This paper evaluates and compares the probabilityfrequency ratio (FR), statistical index (Wi), and weighting factor (Wf), used for assessing landslide susceptibility in the study area. Eleven landslide influencing factors were considered in the analyses. These factors included lithology, land cover, curvature, slope inclination, slope aspect, drainage density, elevation, distance to lake and stream, distance to road and trenches and two indices (the stream power index (SPI) and the topographic wetness index (TWI)) found in the area. The accuracy of the maps produced from the three models was verified using a receiver operating characteristics (ROC). The verification results indicated that the probability-frequency ratio (FR) model which was developed quantitatively based on probabilistic analysis of spatial distribution of historical landslide events was capable of producing a more reliable landslide susceptibility map in this study area compared to its other counterparts. About 89% of the landslide locations have been predicted accurately by using the FR map.