Coastline and geomorphological deviations using DSAS techniques over the past 5 decades (1972–2022) in Tirunelveli District, Tamil Nadu, India

Understanding the dynamics of shoreline change is essential for efficient coastal management. This research provides a thorough analysis of the long-term changes to the shoreline in the Tamil Nadu district of Tirunelveli, India, spanning five decades (1972–2022). Remote sensing techniques and digital shoreline analysis techniques were employed to investigate the temporal variations and underlying mechanisms influencing shoreline dynamics. Remote sensing methods include satellite imagery analysis, digital shoreline analysis techniques involve GIS-based mapping and measurement of coastal features. The statistical methods like EPR, LRR and NSM techniques were used in this study to identify the shoreline changes. It considers the sedimentary structures of tidal flats and grain size investigations in the region to improve our comprehension of the geological characteristics and sediment dynamics driving shoreline alterations. The findings demonstrate how the shoreline location at Koodankulam changed considerably during the course of the research. This study report spans a sizable length of time and provides significant insights on the long-term behaviour of the Tirunelveli district coastline. Sedimentary structures and grain size investigations provide insights into erosion, deposition patterns, and sediment transport, crucial for understanding shoreline dynamics. The three primary very high erosion hotspots in the research area are Kunjanvilai, Koodankulam, and Kuttam. At a rate of − 23.5, − 23.6, and − 23.6 m/year, maximum erosion is shown by EPR, LRR, and WLR. This study outcomes major two regions like Vijayapathi and Anjugramam are facing more accretion zone. A maximum of 13.33, 11.14, and 11.14 m/year is shown by EPR, LRR, and WLR. According to projection research, the spans will measure 60.67 km in 2042 and 59.62 km in 2032, respectively.