Assessing tropical cyclone impacts in coastal Bangladesh: A change detection analysis on cyclone Bulbul using geospatial analysis and remote sensing techniques

Abstract

The coastal regions of Bangladesh are highly susceptible to the impacts of tropical cyclones, which frequently pose substantial challenges for disaster management. This research aimed to analyze the immediate consequences of significant catastrophic disasters imposed on coastal regions using geospatial techniques. Cloud-free satellite images and a support vector machine learning algorithm were utilized to examine the outcomes of Land Use and Land Cover (LULC) in the pre- and post-cyclone phase for assessing disaster impact. This study found that after the cyclone Bulbul, 45.08 km² of land features were changed. It also showed agriculture, bare land, dense vegetation, and settlement areas have decreased by about 4.75 km², 5.55 km², 4.56 km², and 7.72 km², respectively. Instead, the body of water grew at a terrible rate of 22.49 km² in areas turned into water body areas. Cyclone made a considerable impact by increasing the waterbody in this study area by flooding, mainly the southern portion, due to the changing process of land characteristics, which increases (waterbody) and reduces (agricultural, dense vegetation, barren land, settlement areas). The accuracy of the analysis was supported by the kappa coefficient. The results underscore the vulnerability of the coastal region and emphasize the need for effective post-cyclone recovery strategies. The study hamper valuable insights into the dynamic changes in the landscape following a cyclone, shedding light on the socio-economic and environmental implications. Further research is recommended to explore the long-term impacts of cyclones on coastal ecosystems and communities, considering the changing climate patterns.