ASSESSING THE IMPACT OF CLIMATE CHANGE ON LANDSLIDE FREQUENCY IN NAKHON SI THAMMARAT PROVINCE, THAILAND

Abstract

Landslides are a form of hydro-geohazard causing significant damage to property, infrastructure, and even loss of life. The occurrence of landslides is significantly influenced by changes in daily rainfall due to climate change and climate variability. Hence, this study aims to predict changes in landslide frequency under the influence of climate change. Utilizing five CMIP6 climate models under SSP2-4.5 conditions to predict future rainfall, global climate model simulations of rainfall are adjusted and corrected using the linear scaling bias correction technique. To determine the critical rainfall threshold, the rainfall threshold for landslide early warning was utilized, implemented with rain gauges. The analysis performed was used to predict changes in landslide frequency over the next 20 years, divided into four periods between 2023 and 2042. To analyze the changing landslide frequency, the future period was compared against the historical period from 2010 to 2014. The results obtained show a fluctuating landslide frequency in Nakhon Si Thammarat province, Thailand. Nevertheless, the analysis indicates a general trend of increasing landslide frequency compared to the historical period. In the eastern part of the province, the number of excess rainfall days is found to be higher than in the western part of the province.