Geo-spatial Analysis of Erosion Accretion Dynamics and Areal Changes Along Digha Coastline in West Bengal, India

The coastal environment on the east coast of India is under a lot of pressure. There are many natural (erosion, storms, and sea level changes) pressures on the coast. Waves and storms are constantly reshaping the coastline. This study on shoreline change can help evaluate the trend and pattern of shoreline changes. This work applied GIS (Geographical Information System) and remote sensing (RS) methods through multi-temporal sensor images with the extension of Digital Shoreline Analysis System (DSAS). The outcome of this analysis revealed that there had been an increase in erosion along the coastline. Length 30.93 km (approximately) coastal stretch divided into two segments to calculate the change rate from 1975 to 2017. Satellite images have been analyzed and identified the vulnerable areas of high coastal erosion. Land accumulation is another interesting part of it where 1989–2003 time span shows the maximum accretion along the entire study area. 10.47 m/year accretion has been observed in those time period. Digha-Mandarmani (including Talsari estuary, Udaipur, Digha, Digha estuary, Shankarpur, Tajpur, Chandpur, Mandarmani, Mandarmani estuary, Dadanpatrabar) coastal area in West Bengal had been chosen. The result shows that the net change and erosion rates are enhanced in Digha and Mandarmani estuaries, Talsari, and Dadanpatrabar. The study shows that there has been a continuous decline in the width of the coastline. By studying these zones, we can create plans to prevent too much erosion in certain areas while still allowing for natural fluctuations. The present study signifies the need for coastal zone protection since some of the field areas are under the most critically risk-prone and vulnerable conditions. The erosion accretion rate provides the necessity of the coastal zone mitigation.