Storm Surge Hazard Assessment Along the East Coast of India Using Geospatial Techniques

Abstract

The present study is to estimate the inundation extent and depth to estimate the extent of damage using geospatial technique caused due to a storm surge. This is achieved by selecting a worst-case cyclone track (Super Cyclonic Storm) scenario for three Indian states, Andhra Pradesh, Odisha and West Bengal based on the historic data. Over 1300 cyclones are observed to have hit the east coast of India in the past 173 years, which is about an average of more than 7 cyclones per year. Geospatial model results for Orissa cyclone (1999) suggests that over 2,150 km2 of land is submerged due to storm surge. The inundation was observed up to an extent of 45 km inland upright to the shoreline with over 1,100 km2 area submerged 1-2m from ground level. This is the worst cyclone (with peak speed 140 knots) of the country known so far to have caused maximum damage. The storm surge model of Andhra cyclone (1996) suggests that about 450 km2 of area inundated due to storm surge where majority of the area is submerged up to1m of water pile. The most affected place is Mummidavaram. Whereas, the results of storm surge model for the state of West Bengal is carried out using a synthetic track passing through West Bengal coast with wind speed of 155 knots (worst case). The model result shows 5,400 km2 of land submerged up to 1m of water and about 2,700 km2 of area submerged under 1-2m of water. The most affected area is South 24 Parganas and parts of Bangladesh. The results of the current study are useful for the coastal cyclone disaster management in order to make decisions on preparedness and disaster risk reduction. These results can also be used for the coastal future development purposes.