Shoreline change study between Vembar and Tharuvaikulam coastal zones along the coast of Thoothukudi district, Tamil Nadu, India, using remote sensing and GIS techniques

Shoreline change study is very challenging for any coastal scientists because of its dynamic changes. Erosion and accretion processes directly control the shoreline and coastal landforms. The present study is attempted to assess the shoreline changes between the Vembar and Tharuvaikulam coast of the Thoothukudi district, Tamil Nadu, India. Both the places were regarded as two zones viz. Vembar and Tharuvaikulam zone. These zones are further sub-divided into three grids to understand and mark the erosion and deposition zones. The shorelines were digitized from satellite images of Landsat – 5 (1997) and Landsat – 8 (2018), and also the base details were extracted from a survey of India (SOI, 1968). These shorelines were taken to Geographic Information System for overlay analysis to determine the extent of erosion and accretion in the study area. The result of this study shows that during the period 1968–1997, Vembar and Tharuvaikulam zones have noticed accretion with a rate of 6.9 m2/y and 4.5 m2/y, respectively. Whereas, during the period 1997 – 2018, the Vembar zone was subjected to erosion with a rate of -1 m2/y. While in the Tharuvaikulam zone, the accretion process has reduced with a rate of 0.1 m2/y. The study results have shown that the Vembar zone has undergone erosion, whereas; the Tharuvaikulam zone has undergone both erosion and accretion. The accretion process rate is less compared to the erosion process during 1968 – 1997. The study concludes that the erosion is increasing due to natural and human intervention.