Implication of Shoreline and Nearshore Morphological Changes on Sediment Budget of Wave-Dominated Chennai Beach, India

Abstract

The study examines the shoreline (1990-2019) 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 non-monsoon 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 east-southeast. 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 non-monsoon. 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.

Utilizing fluctuation asymmetry to assess the effects of U-238 radioactivity on the marine ecosystem around the Madras nuclear power plant, India

“…The seasonal patterns of U SW and U SE showed the greatest values of radioactivity (26.95 and 0.6 Bq kg -1 , respectively) in Mon season (Fig. 4), due to the coastal morphology and processes longshore/cross-shore movement and sea current direction (Southeast /Southwest) (Aubrey 1979;Saravanan & Chandrasekar 2010;El-Taher et al 2018;Shetty et al 2022, AL-Sharif et al 2023. Furthermore, the values of characters 7 and 8 reported minor values below 0.20, and they exhibited the same seasonal trend as characters 3.…”