Historical and Projected Future Hydrological Characteristics of the Mangrove Forest in the Ganges Delta—A Review

Mangrove forests protect coastlines from erosion, enhance biodiversity, store carbon, and support coastal communities. These ecosystems rely on hydrological conditions. This paper reviews past, present, and future hydrological characteristics of Bangladesh’s Sundarbans to guide restoration and sustainable development. It examines historical and projected hydrological indicators, addressing knowledge gaps and suggesting strategies. Renowned for productivity, biodiversity, and socio-economic benefits, the Sundarbans depend on seasonal freshwater from the Ganges River. However, threats from climate change and human activities, including reduced freshwater flow due to India’s Farakka Barrage on the Ganges, rising salinity, cyclones, and pollution, endanger these ecosystems. The primary threat is mangrove destruction for alternate land use and reduced sediment supply due to upstream dam construction. Sea-level rise is a secondary concern, as a healthy Sundarbans delta could naturally accrete with adequate sediment input and mangrove growth. Sustainable management practices are critical, including maintaining upstream water flow, minimizing deforestation, and rehabilitating degraded areas. Alternative livelihoods and strategies addressing salinity rise are essential. Long-term approaches should adopt adaptive management and ensure sustainable resource use. Policy actions must regulate human activities, mitigate cyclone impacts, ensure freshwater availability, halt harmful industries, and promote awareness and surveillance. Protecting mangroves to reduce CO2 emissions and advancing research are vital.