Landslide Hazard Risk Assessment Using GIS and Analytical Hierarchy Process (AHP) Approach: Evidence from 2017 Rangamati Hill Tracts Landslide Event, Bangladesh

A large number of local people and property losses have been reported in the Rangamati Hill Tracts (RHT) of Bangladesh due to the 17 June 2017 Landslide event. This chapter investigated the actual causes of this landslide event which focuses on the coupling effects of earthquake-rainfall-induced landslide activities that occurred in this area. To know this scenario better, the study considered freely available earth observation multi-temporal Landsat satellite scenes for landslide-induced change assessment. In addition, thirteen associated conditioning factors were integrated within the GIS environment by adopting a multicriteria analytical hierarchy process (AHP) approach to prepare a landslide hazard risk (LHR) map of the study area. The study results quantified 3.81, 3.00, and 8.90% of areas as very high-risk, high, and moderate LHR categories. Moreover, the results also revealed that multiple issues (i.e., earthquakes, heavy rainfall, hill cutting, deforestation, and haphazard human settlement construction on the hill slope) are the main catalysts behind this landslide event. Finally, the study recommends integrated Remote sensing, GIS, and AHP techniques for future landslide risk assessment across the globe.