Cyclone exposure mapping in coastal Bangladesh: A multi-criteria decision analysis

Owing to its geographical location, Bangladesh is highly exposed to natural disasters: the northern part is at risk of floods, while the southern part suffers from cyclones, storm surges, and salinity intrusion. This study aims to quantify the exposure to cyclones in Taltali, a southern coastal upazila of Bangladesh. To quantify the exposure, the study used 6 criteria, including elevation, slope, proximity to major water bodies, population density, proximity to cyclone tracks and land use and land cover, and produced maps focusing on each criterion. The overall exposure map was also created to observe the whole scenario of the upazila. All the analysis was done in a GIS environment using the Analytic Hierarchy Process (AHP) method. The individual criterion map represents the status of the study area in different classes. And the overall exposure map revealed that about 60 % of the study area was quantified as very highly exposed to cyclones, including 4 unions- Barabagi, Chhota Bagi, Karaibaria, Pancha Koralia and 6 Rakhain paras- Taltali, Monukhe, Momeshi, Agathakur, Saton, and Sawdagar. In numerical terms, about 8032 ha and 178 ha of land are counted as highly and moderately exposed to cyclones, respectively. Among the seven unions, the maximum area of the Barabagi and Chhota Bagi was found to be very highly exposed, followed by Panchakoralia and Karaibaria. Data from our previous study also validated the results of this study. Despite having some limitations, the study can be used to develop the capacity of the community to respond to cyclones. And the national and international communities can use the results to formulate policies regarding disaster risk reduction and risk mitigation.