Landslide Susceptibility Mapping Using Weighted-Overlay Approach in Rangamati, Bangladesh

摘要

Rainfall-induced landslide hazards have become a common phenomenon in the Rangamati Sadar area of the south-eastern folded part of Bangladesh. The area has experienced several landslides in 2017, which caused loss of life and enormous loss of the asset. The present study aims to map landslide vulnerability in the Rangamati Sadar area and the surroundings. The weighted overlay approach such as the knowledge-based empirical technique is commonly used for landslide vulnerability mapping. The susceptibility map has been derived using various parameters-geology, land use, DEM, slope, aspect, soil texture, and structure/lineament data taken from an open-source geospatial platform. Mapping procedural justification and authentication are confirmed based on past landslide locations and field visits. The landslide susceptibility map is categorized into very low (236.4 km(2)), low (196.8 km(2)), moderate (1076.2 km(2)), high (1613.8 km(2)), and very high (2615.7 km(2)) susceptible areas. The end map of the research area is validated using an image overlay on google earth-2021 and the area under the curve value of 52 landslides events. The weighted overlay approach has displayed an important presentation that the area under curve (AUC) value is 0.875. Statistical analysis has identified the most recent devastating landslides due to climate change along with other anthropogenic causes such as hill cutting, soil texture, and deforestation. The research outcome would help the stakeholders and policymakers reduce and mitigate the risks related to landslide hazards in the associated areas.