Assessing the Impact of Coastal Erosion on Land use and Landcover, A Time Series Analysis using DSAS and GIS in Cuddalore Shore, Tamil Nadu, India

Abstract

Abstract One of the most fragile places on earth is the coastal zone. There are several different ecosystems in this area. In this area, erosion and accretion are typical natural occurrences. These changes could also threaten the coastal ecology. Uneven coastal changes can result from natural processes such rainfall, cyclones, floods, tectonic shifts and longshore drift. Similar to this, anthropogenic influences like mining, unscientific land use, urbanisation, etc., contribute to coastal processes and bring much more significant alterations in the coastal region. Therefore, identifying such a location is crucial. Advanced approaches for studying shoreline change have been made possible by geospatial technology. The enormous effort to obtain an accurate result over a greater area has become easier as a result. In order to examine the changes in the Cuddalore shoreline during the years 2002, 2007, 2013, 2017, and 2022, Landsat satellite imageries with 30 m spatial resolution were used. The Digital Shoreline Analysis System (DSAS) tool for analysing shoreline change has been integrated to Geographic Information System (GIS) software. DSAS was used to construct the baseline transects for the shoreline change measurement. Using the MATLAB feature runtime function for ArcGIS, the rate of shoreline change was computed. Based on the DSAS output, the area of high erosion, low erosion, stable, and low accretion, high accretion zones were assessed on the coastline. The results reveal that 15.38% of the shoreline, around 6.8 km is under high erosion. 12.2% of the shoreline, which is around 5.4 km, is under low erosion. 32% of the shoreline, around 14.5 km, is a stable region. 26.9% of shorelines, around 11.9 km, is low accretion, and 12.6% of shorelines, around 5.6 km, is high accretion. The coastal villages, namely, Gundupallavadi, Cuddalore, Thandavarayancholanga pettai, Ariyakoshti and parangipettai have a high erosion with a maximum rate of change between -3 to -14 m/y. The coastal villages Patchayankuppam, Cuddalore, Tiruchchepuram, Kayalpattu, Kothattai, Ariyakoshti, Parangipettai have high accretion with a maximum rate of change between 3 to 10 m/y.