Assessment on Physical and Anthropogenic Activities and Its Impact on Coastal Sand Dunes, West Bengal

Abstract

Sand dunes are topographical height in the low-lying coastal plain of west Bengal. They protect wave attack in the low-lying areas, shelter land ward communities and assist in the retention of fresh water tables against salt water intrusion. Sand dunes are developed along the coast belt with three basic processes: Supply of sand to the beach plain, aeolian sand transport from the beach to the backshore region, and interaction between sand transport by the wind and vegetative growth or distribution. It is useful to regard a dune like a savings account of a bank. At present, of the entire coastal ecosystem, sand dunes have suffered greatest degree of human processes. Many dune systems have been irreversible altered through the activities of man, both by accident and design. Ecosystem components of the sand dunes are affected by the intensive use of dunes in the coast. Artificial structures like houses; hotels, fishery etc are disturbing the normal growth of the dunes. Removal of sands by road cutting, grazing the dune in Shankarpur, Mandarmoni areas. The level of grazing pressure is instrumental in determining species composition. Dune plants are destroyed by growth of urbanisation, agriculture and costal defence programme. We observed and measuring the rate of coastal erosion, it has been remarkable increasing in last decade. The dunes are totally destroyed by increasing wave action at many places. Accelerated dune erosion by the cyclonic storm, tidal bore and wave action. It has been observed that the front dunes are eroded and also shifted landward at the rate of 6 m to 12 m/year of this area. Certain conservation measures have been recommended including mechanism of dune maintenance by artificial simulation, dune creation and control of coastal water pollution from hotel sewage and fisheries waste water.