Shoreline Dynamics of Dhanushkodi, Rameswaram Using Gis

Abstract

Coast is a zone of intense energy input. This energy transported by waves, tides, and wind arrives at the coast which set the processes of sediment transport in motion that causes the morphological changes. These changes will continue indefinitely until an equilibrium condition is reached which results in no net sediment transport. The study area of Dhanushkodi is at the eastern end of Rameswaram Island. Tamilnadu, India. The geological terrain and landscape naturally tapers slowly but sharply towards the end, converging and gently sinking into the sea at Dhanushkodi. In the present study, shoreline changes and the sediment dynamics were analysed using toposheets, satellite imagery, beach slope measurement and beach sediment characteristics. GIS overlay of temporal shoreline maps show that the net erosion between 1986 and 1996 is 0.03sq.km whereas between 1996 and 2003 the net erosion is 0.31sq.km. Beach slope along Gulf of Mannar is steeper than Palk Bay. Beach slope at Arichamunai and along Gulf of Mannar gradually decreases from pre monsoon to post monsoon, which shows that continuous erosion took place during the period of observation. The sediment transport directions as well as sources and sinks for sediments during the pre monsoon, monsoon and post monsoon seasons are identified. The results indicate that the direction of sediment transport in pre monsoon and monsoon period is reversed in comparison with the post monsoon.