Shoreline stability in the vicinity of Cochin Harbour

Abstract

A small stretch of barrier beach on either side of Cochin harbour along the west coast of India has been investigated for its stability through systematic surveys. The observed erosion of the beaches during the southwest monsoon is due to an order of magnitude increase in the wave energy. But the accretional tendency of the beaches along the Narakkal zone are due to the presence of static mud suspension in this region during monsoon season. Beaches of Anthakaranazhi exhibited a near-cyclic behaviour, showing stability over a period of one year. The growth of shoreline north of Cochin harbour channel takes place at the cost of sediment that should have otherwise by-passed the estuarine mouth. During the southwest monsoon the development of opposing circulation cells on either side of the harbour entrance channel favours siltation in the channel