Sediment transport mechanism in the Vellar estuary, east coast of India

Textural data of 60 samples of bottom sediments, from 20 transects (approximately 0.5 km apart) collected from the Vellar estuary, indicate that sand is predominant at the head of the estuary with silt and clay as subordinate constituents. The proportion of sand decreases towards the confluence. The silt content is comparatively fewer than the clay content in the downstream direction. However, the central part of the estuary shows a decreasing trend of sand and an increasing trend of clay content. The log-probability plots suggest that all the three segments (i.e. the northern, central and southern sides), of the estuary show an average of one traction population, three saltation and four suspension populations. The variations in textural characters suggest that tidal activity has significantly affected the sediment population and the minor disturbances of other transporting agencies might have affected the depositional process which are marked in the deposited sediments.