Landslide Vulnerability in the Sangu-Matamuhuri River Basin of Southeast Bangladesh

The Hill Tracts of Bangladesh experienced several landslides in recent years. The vulnerability to landslides is a major concern because of rising climatic and man-made impacts. Considering the river basin within these hill tracts with numerous small runoff channels, proper comprehension of the landslide vulnerability is essential for sustainable integrated water resources management (IWRM). The study seeks to evaluate the landslide vulnerability in the Sangu and Matamuhuri river basins using a two-step methodological framework. Firstly, the overlaying of six factors—rainfall, elevation, slope, soil characteristics (lithology), land use and land cover (LULC), and historical events was done to identify vulnerable areas, each of which has been weighted using a pairwise matrix of the analytical hierarchy process (AHP). Secondly, factors that accelerate vulnerability in the basin were explored qualitatively to understand the associated drivers. The investigation pinpointed Bandarban Sadar, Satkaniya, and Rowanchari with the highest vulnerability within the Sangu Basin and Alikadam and Lama within the Matamuhuri Basin. Alongside climate extremes such as heavy rainfall, development activities with unplanned hill cutting, tourism, and deforestation are increasing the basin’s vulnerability. The outcome of this study will aid policymakers in making informed decisions for sustainable and integrated watershed management.