Monsoonal effects on beach and offshore sediments from kalbadevi bay, Ratnagiri, Maharashtra state, India.

Abstract

Sediment samples representing the beach and offshore area of Kalbadevi Bay, Ratnagiri, Maharashtra were studied for different seasons along three east-west beach profiles (BP-01, BP-02 and BP-03) which covered berm, dune, high tide, mid tide and low tide area of the beach, and the sea along their extended offshore profiles (OP-01, OP-02 and OP-03). The major constituent of the sediments from both areas is sand followed by silt, with negligible clay. Comparatively, beach sediments show pronounced monsoonal effects on sand content in the berm area. The shallow (<5m depth) offshore area receives loose sand during southwest monsoon and indicates transportation from beach. During post-monsoon period, it is removed and deposited farther at deeper depths (>10m). It appears that the sediment distribution in the Kalbadevi Bay is partly controlled by the east-west trending depression along the central offshore profile (OP-02). The study shows enrichment in sand and clay content during post-monsoon period rather than during pre-monsoon and/ or transitional period.