Variations in Mean Grain Size as Indicators of Beach Sediment Movement at Puri and Konarak Beaches, Orissa, India

Abstract

Over a four year period, between 1979 and 1982, mean size variations were studied under different environmental conditions in 550 sediment samples along and across 10 beach profiles, 5 each at Puri and Konarak beaches along the coast of Orissa, India. The regular monitoring of the mean size along and across the profiles depicts marked variations in the mean size, associated with changes in hydraulic conditions in time and space. The size contours are parallel to the shore in calm conditions when deposition is prevalent on the beach. Onset of erosion is marked by a lack of parallelism and the size contours become convex seawards. The spacing between the size contours also changes with the nature of the movement of the sediments and is reduced during beach erosion. The variations in mean size in relation to probable source of sediments and change in the nature of the different geomorphic processes are delineated.