Sediment Transport Investigations in Indian Ports Using Radiotracer Technique [Case Study: Radiotracer Applications for Investigation of Bedload Transport of Sediments]

India has a long coastline of about 7640 km, out of which 2650 km is on the East Coast and 3360 km on the West Coast and the remaining is in different islands such as Andaman, Nicobar etc. As compared to the West Coast, the East Coast faces severe wave climate and has a relatively shallow seabed. The major rivers of India i.e. Ganga, Brahmaputra, Mahanadi, etc. discharge into the Bay of Bengal and bring along with them a large quantities of sediments. The sediments are carried along the coast by the alongshore currents generated by the waves breaking obliquely to the coastline. There are twelve major ports, six on the West Coast and six on the East Coast of India. In addition to this, there are over one hundred and forty intermediate/minor ports and other marine engineering projects along the coastline. The locations of the major and intermediate ports of India are shown. The existing ports and marine engineering projects are faced with the problem of continuous maintenance dredging and dumping operations for maintaining the depth of the navigation channels. In addition to this, capital dredging is also carried out during the construction of the new projects and expansion of the existing projects. The dredging operations constitute major expenditure in existing and new projects. The average annual maintenance-dredging requirement in various major ports in India ranges approximately 20-70 million cubic meters. This huge quantity of the dredge material is to be disposed off at suitable locations either inshore or offshore. In case of major Indian ports, disposing off at inshore locations is not economically and technically feasible option. Hence it becomes imperative that the dredged materials be disposed off at suitable offshore locations, from where it does not find its way back to the channel. In addition to this, the selected site should be such that the turn around time of the dredger is kept minimal to economize the dredging operation