Antecedent and Cumulative Rainfall as Thresholds in Detecting Possible Landslide Occurrence

Landslide is one of the world’s natural disasters that are currently gaining attention. Throughout the years of landslide occurrences study, predictive models were developed and a lot of public awareness strategies were conducted to minimize the losses. The occurrence is related to slope failure and heavy rainfall. This paper proposed an alerting solution to an imminent landslide occurrence by identifying rainfall volume as a threshold value. Two study areas which are located 124 km away from each other were analyzed with the help of their past historical landslide. The back analysis method was applied to detect regular and irregular conditions of the received rainfall. The study discovered a similarity in the rainfall pattern at both study areas, where rainfall duration (5-day antecedent rainfall) and total received rainfall (cumulative rainfall) play a big role in initiating landslide occurrence. This method is recommended to implement threshold value as the indicator of imminent landslide occurrence, especially for real-time landslide monitoring purposes.