Nearshore circulation in relation to effluent disposal off Thal, Maharashtra, west coast of India

Abstract

Tides, currents and related field parameters at Thal, Maharashtra Coast, India, were studied to assess the environmental conditions for proper disposal of effluents from a large fertilizer factory. The tidal ranges being 1.6 and 3.9 m during neap and spring respectively, the tidal currents attained a maximum value of 1 m/s during spring and about 60 cm/s during neaps. The spatial variations were considerable, due to the presence of rock outcrops, tidal creeks and two islands. A composite picture of the flow pattern has been prepared for the three prominent seasons. The waters beyond Khanderi Island described a course roughly parallel to the shore, whereas shallower waters exhibited cross-shore tendencies and irregularities, rendering them unsuitable for systematic effluent disposal, as also the southern and middle regions due to limitations in dispersive processes