Sedimentation and coastal area management in the human-modified Ganges-Brahmaputra tidal delta plain of Bangladesh

The present work is an effort to expose the sedimentation rate of the Ganges-Brahmaputra (GB) tidal delta plain from the subsurface-dated sediments samples. The study reveals that the average sedimentation rates (about 2.12-4.59 mm yr(-1)) of the area are not as good to minimize as the estimated range of relative sea-level rise (RSLR) (1-9 mm yr(-1)). Moreover, the sediments cannot be distributed properly in the tidal and fluvio-tidal plains due to different anthropogenic activities like poldering and embankments. In addition, the upstream diversion of the Ganges and the Brahmaputra rivers water reduces the suspended sediment load to the downstream and consequently, the sedimentation rates. Finally, the GB tidal delta plain and its coastal area are in a vulnerable situation in consideration of sedimentation rates, RSLR, and different anthropogenic activities. Therefore, regular monitoring and evaluation is essential about sedimentation, coastal and upstream anthropogenic practices, RSLR, etc., for the implementation of effective and efficient mitigation and adaptation measures in the deltaic plains.