Assessing Resilience to Tropical Cyclones in Coastal Bangladesh: A Synthesis of Geo-spatial Techniques and Social Responses

Tropical cyclones have prolonged detrimental effects on the livelihoods and well-being of coastal residents, particularly in developing countries, but no studies have so far assessed cyclone resilience comprehensively, particularly at a local scale. To address this gap, this study assessed resilience to the 2007 Cyclone Sidr (Category 4) in a coastal sub-district in southwest Bangladesh using geo-spatial techniques and residents' responses to an extensive survey; resilience was assessed in each of three phases: before (pre), during (syn) and after (post) the cyclone. The first objective was to assess ecosystem resilience in terms of the services they provided to the community by creating ecosystem service-supply proficiency (ESSP) maps for the three phases. Change-detection techniques determined the amount of cyclone damage to and the subsequent recovery of each ecosystem. The change statistics and residents’ judgments on the ecosystems’ abilities to provide their services were integrated to produce the ESSP maps. The results showed that all ecosystems were impacted by the cyclone to some degree and recovered at different rates. The second objective was to quantify social resilience by examining the different strategies residents employed to plan for, respond to and recover from the cyclone. Resilience indices were constructed with the help of Principal component analysis (PCA) and GIS. Twenty-two important components were identified, among which basic preparedness, emergency response, social bonding, and reconstruction and rehabilitation were found to be the most influential. The exterior unions, even though close to the sea, were more resilient than the less-exposed interior unions. The third objective was to establish a framework for assessing critical-infrastructure (CI) resilience, the ability of CI units to satisfy users’ needs in the three phases. Both GIS based network analysis and household response were used to accomplish this analysis. The results showed that interior unions were resilient than the exterior unions. The overall research outcomes revealed that even in a local scale (~ 286 km2), disaster resilience varies considerably. The techniques developed in this study should be useful in cyclone disaster management, especially in advising legislators and planners on cyclone risk mitigation policies