Spatiotemporal Variations of Land Surface Temperature and Vegetation Dynamics Impacts on Landslide Intensity in Chattogram Hill Tracts Region of Bangladesh

Abstract

This study was aimed at assessing the spatiotemporal variation and trends of LSTs and vegetation dynamics impacts on landslide vulnerability within CHTs region. The variation trends of land surface temperatures (LSTs) and normalized difference vegetation index (NDVI) between 2001 and 2022 were assessed using time series datasets from the moderate resolution imaging spectroradiometer (MODIS). Relevant data on the multi-variant landslides, causalities and associated datasets were collected from different archival sources and random field investigations were performed for cross verification purpose. Results showed that the variation trends of LSTs between 2001 and 2022 were mostly in an increasing mode (94% grid cells) with a yearly average LST increase of 0.34°C. Contrarily, during the same period, the variation trends of vegetation index were in a decreasing mode, while total NDVI value on average slightly increased by 0.2. Thereafter, the variation trends of LST and NDVI were significantly correlated and most of the grid cells have shown converse correlation. The landslide prone areas are mostly in the above correlation locations. The study further revealed that a total of 469 severe landslide occurrences were recorded in CHT region with Rangamati district being the most affected area with 48.6% severe landslides occurrences. Therefore, this study establishes a strong influence of climate change effects on landslide vulnerability in the CHT region. The study suggests that proper planning, policy recommendations and management of ecosystems will help reduce landslides and mountain disaster occurrences.