Sediment concentration and bed form structures of Gulf of Cambay from remote sensing

Abstract

The continental shelf on the west coast of India is the widest off Mumbai and leads to a strongly converging channel, the Gulf of Cambay (GoC). Tides in this Gulf are the largest on the Indian coast. The flow‐generated bed forms are significant features in the Gulf of Cambay region, and their presence depends on strong tidal or other currents, capable of moving the sand and also on the availability of sand. Digital data collected onboard Indian Remote sensing satellites IRS‐1C and IRS‐P4 OCM (Ocean Colour Monitor), covering the GoC region was digitally processed. False colour composites (FCC) of IRS‐1C were generated and used to map coastal, near‐shore geomorphic features and underwater flow‐generated bed form structures. Suspended sediment concentration and their dispersal patterns were studied by processing IRS‐P4 data. The impact of high tides on the suspended sediment concentration and sediment flow pattern was studied to understand the mechanism of sediment flow. Based on the suspended sediment concentration, flow structures, geomorphic features and hydrodynamics, it is concluded that fine‐grained sediments are transported to the inner Gulf, whereas, sandy sediments are transported south‐westwards and outwards of Gulf of Cambay. These sediments, perhaps participate in the formation of bed form structures.

Acknowledgements

I express my sincere gratitude to Dr Satish Shetye, Director, National Institute of Oceanography (NIO) and Head, Data Centre for permitting me to publish this material. I gratefully acknowledge Japan Society of Promotion of Science (JSPS), Japan, for awarding a JSPS Postdoctoral Fellowship under which this work has been completed at Center for Environmental Remote Sensing (CEReS), Chiba University. Indian Remote Sensing Satellite (IRS) and ocean colour monitor (OCM) data used for this study was procured under COMAPS Project. Sea truth data was obtained from Data Centre, NIO. The author gratefully acknowledges Regional Remote Sensing Service Centre, Nagpur for providing OCM data processing software package. The author is also thankful to anonymous reviewers, who helped in improving the manuscript. This is NIO contribution number 4253.