Hydro‐meteorological variability in the greater Ganges–Brahmaputra–Meghna basins

Abstract The flows of the Ganges, Brahmaputra and Meghna (GBM) are highly seasonal, and heavily influenced by monsoon rainfall. As a result, these rivers swell to their banks and often overflow during the monsoon months. This is most pronounced in the downstream regions, particularly in Bangladesh, which is the lowest riparian country. The objective of this paper is to study this hydro‐meteorological variability in the greater GBM regions, including the headwater regions in India and their role in streamflows in Bangladesh, and explore the large‐scale oceanic factors affecting this hydro‐meteorological variability. Global precipitation data, Bangladesh rainfall and streamflow records have been analysed and related to large‐scale climate patterns, including upstream rainfall, regional atmospheric circulation and patterns of sea‐surface temperature. The…