Rainfall-induced landslide thresholds development by considering different rainfall parameters: a review

This paper reviews the development of landslide thresholds from the perspective of rainfall and climate patterns. For certain, geology, morphology, lithology, etc., contribute to the initiation of the mass movement. However, the role of rainfall as the triggering mechanism of the landslide is vital as well. It has been proven by many researchers from various studies worldwide that have proposed the rainfall thresholds by utilising different rainfall parameters. The outcome of their studies is interesting, since different regions have diversified patterns of rainfall that produce a variety of threshold models. Therefore, from various published papers on rainfall thresholds, this paper studied the variety of rainfall parameters that have been utilised in establishing the rainfall threshold for landslide prediction. Instead of providing a better understanding regarding the application, this review aimed to cultivate the folllowing study for deriving rigorous parameters for the purpose of sustainable findings

Rainfall-induced landslides in Cameron Highland area, Malaysia

Cameron Highland is classified as one of the landslide-prone areas in Malaysia due to its hilly landform. It has been discovered that the landslides in Cameron Highland were mainly triggered by the intense rainfall since the area encountered high amount of rainfall throughout the year. This study is carried out to evaluate the correlation between the rainfall intensity- duration (I-D) and the landslide occurrences in the Cameron Highland area. Twelve cases of landslides in the study area had been selected for conducting the analysis of rainfall intensity- duration (I-D) that triggers the landslides. The important variables from the analysis such as the maximum rainfall intensity (I) and the duration of rainfall series (D) have been applied to establish the empirical rainfall intensity-duration (I-D) threshold for Cameron Highland landslide areas. Based on the study, by utilising the logarithmic scale graph and applying a power-law model from the general equation of I= αD-β , the empirical I-D threshold for Cameron Highland landslide was determined as I = 29.088D-0.075 (I = rainfall intensity in mm/hr and D = duration in hour). The empirical (I-D) threshold can be a functional mechanism for the Early Warning System (EWS) once it is further developed, that enable the relevant authority to prepare mitigation measures such as evacuation, spreading information to the civilian in order to prevent major losses and casualties due to the landslide event