Estimation and Modeling of Shoreline Changes by the year 1970-2100 between Portonova to Mallipattinam coast using Remote Sensing and GIS

Changes in shoreline configurations accelerated due to global warming are world wide concern. Such changes not only affect the flora and fauna of those regions but also the livelihood of the coastal population. In the context, the 7517km long coastline of Indian coast behaves differently in different regions. Therefore, in order to assess the shoreline changes taking place in particular coastal regions and predicting the long-term changes in shoreline, there is an urgent need to monitor shoreline changes in different sector of Indian coast. The data generated through such can be very much helpful in taking the policy decision in establishing the various coast facilities in those regions. Shoreline Oscillation map of Bay of Bengal and Palk Strait area on 1:50,000 scale was prepared. In view of the above 1970 Topographic Sheets of Survey of India (SOI) and the National Remote Sensing Agency (NRSA), Hyderabad, India, Landsat TM 5, IRS P6 Imagery of the year 2000, 2008, IRS LISS III P6 Feb 2005, April 2006, March 2008 Satellite Imageries and Modeling 2100 are utilized to study a 200 kilometer long coastline of central Tamil Nadu Coast between Portonova and Mallipattinam to understand the shoreline changes taken place within a time span of 38 years. Comparative Shoreline Oscillation map reveal high erosional sedimentation ratio to the extent 73.24 in the sector of Thirumullaivasal to Topputurai during 1970 to 2000. Based on this study it can be concluded that remote sensing technique will be useful in long term qualitative monitoring of shoreline oscillations. Further the remote sensing study has a good agreement with the physical and observation of shoreline oscillation. The coastal stretch at Portonova, Kodiyampalaiyam, Kameswaram, Naluvedapathi, Periyaguttagai, Muttupet, Mallipattinam were in accretion and quite suitable for tourism like activities where as Killai, Thirumullaivasal, Poompuhar, Tharangambadi, Karaikkal, Nagore, Nagapattinam, Velanganni, Kodiyakkarai, and Atirampattinam and shorelines were in erosion and require attention from coastal authorities. The difference of rate of erosion/ accretion between the remote sensing study and physical observation was due to the coarser resolution of satellite images. The research deals in detail the sector wise shoreline variation along the 200 km long coastline of central TamilNadu. This study future emphasizes the need to extend similar studies along the other parts of the Indian Coast.