Decadal Changes in Shoreline Patterns in Sundarbans, India

Abstract

parameters, both natural (atmospheric, physical, chemical and geological) and anthropogenic (pollution, tourism, deforestation). We submit here an assessment of changes in shoreline pattern of 14 islands in Indian Sundarbans (ISD) since 1979. Using multi temporal satellite images of LANDSAT, we found that as many as four islands within ISD have lost area in excess of 30%. While the area loss for another three islands has been between 10 and 30%, five islands show minor loss of area (<10%).The shoreline variations in two other islands, however, are of extreme nature. While the Lohachar Island on the river Hoogly was completely submerged by the end of the last century, the neighboring Nayachar Island on the same river has gained more than 30 km 2of land area.An interesting difference in nature of land loss is seen between western and eastern group of islands. Over the last 32 years, the total loss of area in six western islands (Ghoramara, Sagar, Jambudwip, Mousuni, Namkhana, Lothian) has been 23.64 km 2, while another six islands from eastern Sundarbans (Surendranagar, Dhanchi, Bulchery, Chulkati, Dalhousie and Bhangaduani) have lost about 53.85 km 2of land area. The role of vari ous forcing parameters, such as long shore current, abnormal tidal heights, subsi dence, tilting of crust and sub -surface geomorphology, in effecting changes in shoreline pattern in 14 Islands of the Indian Sundarbans are discussed.