PRESUME AND REAL BATHYMETRY OFF BAY OF BENGAL REGION USING MIKE 21 HD MODULE

Abstract

The study of ocean flow field, principally due to tides, has assumed a new dimension in the wake of surging coast based developments be it in the form of ports and harbours, offshore structures, power plants etc.  In the Indian coasts, the tides are generally semidiurnal.  In the offshore region where the depth is enormous the influence of tidal range is not keenly felt as must in nearshore waters which constitute the nucleus of developmental activities.  In view of this, the authors felt that ‘tide’ is an important parameter which needs to be studied in more depth keeping in the ground realities in the east coast of India-which is steadily becoming the cradle of industrial developments. For this purpose, the tide induced flow fields were simulated using nested grid systems with MIKE 21-HD module. The results reveal that the tidal range increases monotonically from south to north showing by and large a weak tide induced current. The study area chosen for the present analysis extends from Nagapattinam (Tamilnadu coast) to Paradip (Orissa coast).The intensity of tide induced current varies from 0.075m/sec near Nagapattinam to 0.249 m/sec near Paradip.   The intensity was seen to be in agreement with simulations carried out for all the tidal constituents pot together including M₂ and S₂.  The result shows that that the magnitude of the simulated tide induced currents at about 20m depth slowly increases from south to north to an extent of 0.249 m/sec, which needs to be reckoned with in coastal development projects where even such small increase carries some significance-sya in littoral transport computations.