Assessment of Coastal Erosion along the Indian Coast on 1:25,000 Scale Using Satellite Data of 1989-1991 and 2004-2006 Time Frames

The long stretch of coastline on either side of the Indian peninsula is subjected to varied coastal processes and anthropogenic pressures, which makes the coast vulnerable to erosion. There is no systematic inventory of shoreline changes occurring along the entire Indian coast on 1 : 25,000 scale, which is required for planning measures to be taken up for protecting the coast at the national level. It is in this context that shoreline change mapping on 1 : 25,000 scale for the entire Indian coast based on multidate satellite data in GIS environment has been carried out for 1989-1991 and 2004-2006 time frame. The present communication discusses salient observations and results from the shoreline change inventory. The results show that 3829 km (45.5%) of the coast is under erosion, 3004 km (35.7%) is getting accreted, while 1581 km (18.8%) of the coast is more or less stable in nature. Highest percentage of shoreline under erosion is in the Nicobar Islands (88.7), while the percentage of accreting coastline is highest for Tamil Nadu (62.3) and Goa has the highest percentage of stable shoreline (52.4). The analysis shows that the Indian coast has lost a net area of about 73 sq. km during 1989-1991 and 2004-2006 time frame. In Tamil Nadu, a net area of about 25.45 sq. km has increased due to accretion, while along the Nicobar Islands about 93.95 sq. km is lost due to erosion. The inventory has been used to prepare a Shoreline Change Atlas of the Indian Coast.