Geospatial-Based Coastal Risk Assessment of Gujarat Coastline

Nowadays due to the change in climatic conditions and proliferation in sea level, the coastlines are under high threat. The Gujarat coastline is studied in the current work. It is the longest coastline in India and is highly vulnerable to cyclones, earthquakes, floods, landslides, etc. These facts show the relevance of the present research. The parameters based on which the coastal vulnerability index is laid include seven physical parameters and one social parameter. The seven physical parameters are rate of shoreline change, coastal slope, coastal elevation, geomorphology, significant wave height, tidal range, sea level rise, and the social parameter is population density. The additional parameters used in this study, to increase the accuracy of the vulnerability index are coastal elevation, rise in sea level, and population density. The study is done using geospatial data and various other models and is analyzed with the help of geospatial tools. The high-resolution Cartosat DEM data is used to analyze the coastal elevation and makes this study stand out from the previous studies. Using the risk rating of each parameter, the coastal vulnerability index is prepared and it divides the coast into four zones, that is, very highly vulnerable, highly vulnerable, moderately vulnerable, and low vulnerable. According to the analysis, about 43.5% of the coastline is under highly vulnerable zone and about 1% is under very highly vulnerable zone. The study shows that the area under high erosion is basically tidal flats and mangroves.