Radiotracer investigation for bed-load movement at New Mangalore Port, Mangalore, India

Abstract

Radiotracer investigation was carried out at New Mangalore Port (NMP), Mangalore to examine the suitability of dumping site for dredged sediment at north of port approach channel. Scandium-46 (8 Ci) as scandium glass powder having the particle size distribution ranging from 60-100 microns was used as a radiotracer. Tracer was injected onto the seabed at the site using a remotely operated injection system and its movement was tracked using waterproof scintillation detector. Tracer concentration curves were plotted for different trackings, direction and spread of tracer was obtained from the curves. Analysis of the data showed that the sediment predominantly moves towards north-west direction during all the four trackings carried out. Based on the investigations, it is found that the proposed site is suitable for disposing the dredged material, during the season of observation as the movement of sediment is away from the shipping channel.