Spectral characteristics of the coastal currents off Thal, Bombay during a fair day

Abstract

A typical one-day record of currents measured every 20 min. with a direct reading current meter at an anchored station of mean water depth about 8 m off Thal (Bombay Coast, India) during a fair day was subjected to spectral analysis to identify the characteristics of the alongshore and on/offshore components of the coastal current. The spectra for the surface, mid-depth and the bottom levels exhibited tidal harmonic effect more on the on/offshore components whereas the alongshore currents at the surface were prominently influenced by winds. The net drift during the day at these three levels was largely towards south (3 cm s-1) and towards the coast (6.5 cm s-1). The implications of some of these features in the effluents disposal through a submarine pipeline are indicated