Analysis of shoreline change and the problem of saltwater intrusion: a case study on south-eastern part of Sagar Island, West Bengal, India

The problem of coastal erosion is increasing at a large scale due to the changing climatic and other environmental factors. The northern and south-eastern part of the Sagar Island, India shows the signs of accretion after 1980. On the other hand, the southern coast of the region came under the impact of severe erosion. Multi-temporal satellite data have been used for analysing the change of shoreline along the coast of Sagar Island. The areal change of the Sagar Island shows that 10.78 sq.km. of the land has been eroded whereas deposition or accretion has taken place on 8.16 sq.km. of land during 1980-2017. Due to the inherent quality of land and breaching of the embankment, the problem of coastal erosion became acute in the region. It leads to further degeneration of the land causing intrusion of saltwater in the southeast part of the island. Soil samples have been collected to observe the change in the salinity levels around the region. In the village of Boatkhali, due to the problem of saltwater intrusion into the agricultural fields and decreasing productivity of the land, these lands have been converted into fishing grounds. Most of the inhabitants of the region are living with a low standard of living and are unsatisfied with the government measures of protecting land from the impact of high energy waves.