The Ganges-Brahmaputra-Meghna (GBM) mega-delta, the largest and most densely populated delta system in the world, is constantly threatened by overexploitation, saltwater intrusion, decreasing freshwater availability, land subsidence, and pollution due to anthropogenic and climatic pressures, leaving the delta and its people facing existential environmental threats.
The BDP2100 seeks to ensure sustainable water management to mitigate future water scarcity, and urgently develop effective techniques and strategies for safe water use. The Coast-Water-Solutions project aims to close crucial knowledge gaps on the coastal water system and develop much-needed science-founded strategies to secure future access to clean fresh water. Therefore, understanding of availability of current and future usable water, and co-creating effective management strategies alongside appropriate technologies are imperative to ensure future food and water security. Formulating appropriate and inclusive surface- and groundwater management strategies are essential (i) to develop sustainable practices of water (re-)use, and (ii) to improve Bangladesh’s resilience to water scarcity. This project aims to create integrated system understanding on the water system, i.e. spatiotemporal interactions between surface- and groundwater, sediment fluxes and the deep subsurface, and use this to develop site-specific effective technologies and strategies suitable for implementation in Bangladesh.
We aim to understand and quantify the fresh and saltwater system of the coastal delta at the surface and subsurface, quantify land subsidence and saltwater intrusion following groundwater extraction, and assess trends and impacts of hydrological extremes in this climate-vulnerable delta. Through this systems’ understanding, we will co-create sustainable and inclusive water development and management strategies for using appropriate technologies, e.g. Managed Aquifer Recharge (MAR), disaster resilient ponds along with promoting water saving and reuse, optimization of MAR for drinking and agricultural water sources, using a water and food systems approach. MAR solutions have been piloted before in Bangladesh with limited success and one aim of this project is to better understand and unravel the multi-facet factors, i.e. hydrogeological and socio-economical, governing MAR success through a living lab capitalizing a previous installed (Dutch-funded) MAR pilot sites. Locating surface water bodies, preserving and upgrading those as fresh/ rain water reservoir could be another way augment the water reserve in coast.
The insights gained in the living lab will be transferred and upscaled to other places through an integrated, multi- and transdisciplinary approach that will: (i) enhance understanding of the current water system using hydrological and geophysical measurements, and (ii) develop a new integrated model linking saline and fresh surface- and groundwater, sediment transport and geomechanical models. In collaboration with stakeholders, including the local population and organisations, integrated system understanding will be constructed and applied to evaluate and co-create feasible and effective water management tools and strategies to support implementation of the BDP2100.
