Study on Morphological Changes in and around Nayachara Tail Using Remote Sensing Techniques

Abstract

Nayachara, a small island of unconsolidated alluvium, located at the confluence of the Hooghly River and the Haldi River at the northern extent of the Bay of Bengal. The island is prone to tidal effects and cyclonic activities. The complex geomorphological and hydrological study along with remote sensing techniques are applied for understanding the recent morphological changes arising out of rapid growth of small islands just downstream of southern tip of Nayachara Island generally known as Nayachara tail. The present study has analyzed the change in area in and around the Nayachara tail through erosional, depositional and tidal activities during the last four decades using multitemporal satellite images. Some basic hydro-geomorphological parameters like velocity and direction of flow, suspended sediment concentration, salinity and average grain size distribution of the bed material have truly enriched the study. Besides, a comparative bed profile study with super-imposition of contour lines of cross sections also have a significant role to predict the shifting trend of the tail. Since 1973 the extent of Nayachara tail has gradually been increased. A total of 12.118 sq km land area of Nayachara tail has been obtained as newly developed or appeared on the sea surface during the entire time period of 43 years.