Study of the Impact of Rainfall Trends on Landslide Frequencies; Sri Lanka Overview

Landslides related to heavy rainfall cause widespread property damage and occasional loss of lives. During the last ten years it has become evident that the most devastating landslide events tend to occur as a result of comparatively short duration, high intense rainfall compared to the previously had lower intense prolonged rainfalls. At a time when climate change and global warming issues are considered as hot topics, it is required to evaluate the changes and their impacts on landslides frequencies in Sri Lanka. This study looks at extreme rain conditions in the context of climate change in landslide prone districts in Sri Lanka. Mainly two trend patterns, seasonal distribution of landslides and Annual total time series distribution of landslides were developed to get the effect of climate changes in selected landslide prone districts in Sri Lanka. Identification of extreme rainfall conditions were done based on data collected from the Department of Meteorology, Sri Lanka. The possible trends are discussed using above rainfall variations and the collected landslide frequency data.