Storage Redistribution for Flow Augmentation in the Estuarine Systems of the Ganges-Brahmaputra-Meghna Delta

Estuarine systems of the Ganges-Brahmaputra-Meghna (GBM) delta drain the freshwater inflows coming from the upper catchments of the GBM basins to the Bay of Bengal (BoB). In addition to these freshwater flows, seawater enters the systems through the drainage outlets into BoB. Also, there are cross channels connecting different regions of the estuarine systems. This study applies a one-dimensional hydrodynamic model to the estuarine systems. The result of the model is used to compute the inflows, outflows, and storages of the systems. Using these values, a water balance model is developed that conserves the total storage of the systems attained naturally. The water balance model can be used to redistribute the water storage from a water-surplus region to a water-deficient region through the cross channels by conserving the system storage. The isolines are used to compute the total available channel capacities for different ecosystem resources, i.e., agriculture, fishery, and forestry. The total available channel capacities can be used as an upper limit in re-distributing the storage among the different estuarine systems. This approach can be considered as an alternate approach to augment flow in the water-deficient Sundarbans region.