Wave climate and nearshore sediment transport pattern along the SE coast of India

Abstract

Wave climate along five selected transects covering 580 km length of the SE coast of India was studied based on National Institute of Ocean Technology (NIOT) wave atlas. The wave height of 90% of the waves ranged from 0.5 to 0.8 m whereas for 10% of the waves the wave height varied from 1.5 to 2.0 m along the coast. The wave period usually varied between 4 and 6 s. During the NE monsoon season (January), the wave direction was predominantly ESE whereas during the SW monsoon the predominant direction was SSE. The wave climate data was utilized to estimate the sediment transport rates at 0.8, 2, 5, 10, 30 and 50 m depth contours across each of the five selected transects of the SE coast. The required wave parameters at these depths were calculated using Linear Wave Calculator of parabolic mild slope wave model of Danish Hydraulic Institute (DHI), Denmark. The calculated wave parameters at the different depth contours were given as input to simulate the sediment transport rates at the same depth contours using LITSTP model of LITPACK package of DHI. The remarkable feature identified in the present investigation is that most of the sediment transport was confined to nearshore waters within 10 m depth contour, i.e. within 5 km from the shoreline. The simulated results indicate that the sediment transport rate usually varied between a minimum value of 975 m3/month and a maximum value of 73,967 m3/month. The sediment transport rates along the coast is relatively higher during the NE monsoon season as compared to those during the SW monsoon. © Springer Nature Singapore Pte Ltd. 2019.