Implication of shoreline and nearshore morphological changes on sediment budget of wave-dominated Chennai beach, India

Abstract

The study examines the shoreline and nearshore morphological changes (seasonal) to understand the littoral drift and sediment budget variability. Shoreline change rate depicts erosion (-0.06 m/yr) in the northern sector and accretion (+0.12 m/yr) in the southern sector. Seasonal nearshore morphological changes from nonmonsoon to monsoon period signifies net erosion (-1.8x10 4 m 3 ) in northern sector and net accretion (+2.5x10 4 m 3 ) in the southern sector. Although the lost sediment during monsoon is regained in non-monsoon period, the quantity of sediment gain is reduced in areas with human interventions. The results of the investigation depict the dominance of littoral drift towards north from February to October, when wave approach from east-southeast to south-southeast direction and southwards from November to January when the wave direction was from east-northeast to eastsoutheast. The net longshore sediment transport rate estimated during the study period was 2.6x10 5 m 3 /year in the northern sector and 1.5x10 5 m 3 /year in the southern sector with higher rate attributed to monsoon than the nonmonsoon. Sediment budget results in deciphering the causes of erosion (-1.27×10 4 m 3 /yr) in northern sector and accretion (3.91×10 4 m 3 /yr) in southern sector in the wave-dominated Chennai beach.

Study of the Synergistic Effects of Meteorological, Oceanographic, Biological, and Radiological Parameters (MOBR) on Marine Ecosystems Around a Nuclear Power Plant

“…According to Balaji (1988), the pre-monsoon season is considered the main growth span for most of the benthos; despite this fact, the pivotal ratio of sand decreased the ratio of fauna and flora from 26 and 14 to 1 and 3% at post-monsoon and monsoon, respectively. The domination of sand is a result of the effects of meteorological and oceanographic factors, particularly by waves, seawater current movement from SE and SW coordinate, and the storm weather adds to this dominance (Aubrey, 1979;Aubrey & Ross, 1985;Dubois, 1988;Saravanan & Chandrasekar, 2010;Shetty et al, 2022).…”