Abstract
Climate change is the burning issue and utmost environmental challenge for the world today and Bangladesh is considered as the most vulnerable in recent days. Besides, due to its geophysical setting Bangladesh coast is frequently visited by the cyclone-induced storm surge. The assessment of impact of climate change induced cyclonic storm surge and evaluation of potential adaptive measures requires use of scientifically based and tested state-of-the-art mathematical modelling tools. In this study SIDR (a severe cyclone that hit the coast of Bangladesh in 2007) has been selected to assess the vulnerability of selected two islands Sandwip and Kutubdia. Three different tracks were simulated to assess the effect of position of Landfall for each island. It is evident from the model results that if SIDR comes with 0.59m Sea Level Rise (SLR) and 1.0m SLR during high tide, maximum surge height above land level will be 5.1 m and 5.5 m for Kutubdia island and 6.5 m and 6.9 m for Sandwip island respectively. If the same cyclone comes with 10% increased wind speed during high tide with 59 cm SLR, surge height may increase by 0.9 m for Sandwip island and 0.45m for Kutubdia island. Again, it has been found from the study that 200m, 400m and 600 m width of Mangrove can reduce the surge height by 12 cm, 15 cm and 18 cm respectively. This reduction is not enough but it reduces current speed to one-third from 1.8 m/s to 0.65 m/s at Sandwip island. As it reduces the current speed to a larger extent it is favourable for the stability of the coastal embankment and other coastal infrastructure. In view of the above it is the high time to revisit the coastal infrastructure to make it climate resilient.