I have a new paper, led by Jess Raff, that analyzes sediment transport and sediment budgets in the Ganges-Brahmaputra-Meghna delta, and assesses the implications of sediment flow for sustainability in the face of sea-level rise and the diversion and damming of major rivers.
Sediment that originates in the Himalayan mountains and is transported to the Bengal coast by the large rivers in the Ganges-Brahmaputra-Meghna (GBM) river system, and a large fraction of this sediment is deposited on land along the coast, where it can raise the land and offset sea-level rise.
Many hydrological models suggest that global warming will strengthen the South Asian monsoon, and predict that this strengthening would bring a lot more sediment to the coast.
We used empirical observations of sediment deposition throughout the Holocene (roughly the last 10,000 years) to validate these models and strengthen our confidence in the predicitons of increased sediment transport in a warmer climate. This has the potential to raise the land as sea-level rises, thus improving the sustainability and resilience of coastal communities and avoiding catastrophic inundation of the coast that could displace millions of people.
However, plans to divert large amounts of water from rivers in the GBM system, or to build dams across the rivers, could substantially reduce sediment flow, and this could endanger the coastal region and the people who live there.