Sea level rise and coastal flooding in urban area: the case of Chittagong City Corporation

Abstract

Sea level rise differs among coasts across the globe due to inherent differences in physical settings and human activities. Projection on relative changes in the sea level is important to understand the possible impacts on the coastal areas. It is particularly necessary in the case of urban centres which are located at close proximities to the shore for the assessment of the vulnerability of life, livelihood and infrastructure to the sea level rise. The scope of this study includes making projections on the probable extent of relative sea-level rise in the coastline of Chittagong coast and its bearing on industries in Chittagong which is the second largest city and the commercial capital of Bangladesh. In doing so, this study followed a multistage approach. In the first stage, a relative sea level change was projected for the next 85 years as per the guideline document provided in Nicholls et al. (2011). In the second stage, the inundation map was developed for Chittagong City Corporation by using Digital Elevation Model data on MICRODEM software platform. In the last stage, land cover change was estimated based on the inundation map. The results show that Chittagong city is going to experience a 0.99m relative sea level rise by the year 2100. The analysis considered three scenarios for the projection - the minimum rise of 1 m, the maximum of 3 m and a 12 m rise (including the occasional 9 m storm surges) in order to inform decision makers the extent of impact under various scenarios.