Morphodynamic Change of Fraserganj and Bakkhali Coastal Stretch of Indian Sundarban, South 24 Parganas, West Bengal, India

Abstract

The Bengal plain is characterized by the presence of an extensive coastal tract bordered by the Bay of Bengal in the south. Two contrasting coastal environments are prevailing in the area, namely; the macro tidal Hooghly estuary in the east; and the mesotidal Midnapore Coastal plain to the west. A morphogenetic study based on the terrain mapping unit (TMU) concept reveals the form- process-material interactions of these two contrasting coastal environments with a possible geo-history model of the coastal Quaternaries. It has been established that the entire process-response system of the coastal tract of the Bengal plain started operating after the rise of sea level around 6000yrs B.P. (i.e., optimum of flandrian transgression) and the Hooghly estuary, the mangrove vegetation plays a significant role as the dominant geomorphic agent in the evolution of the tidal shoals and their eventual accretion to the main landmass resulting in delta progradation. In the present-day scenario, the Hooghly estuary becomes the abandoned part of the Ganga-Brahmaputra delta in India, and is also turning destructive and forming erosional regime in the mesotidal Midnapore coastal area.