Climate Change Impact on the Manageability of Floods and Droughts of the Ganges-Brahmaputra-Meghna Basins Using Flood Duration Curves and Drought Duration Curves

抄録

This study investigates the impact of climate change on the manageability of floods and droughts in the Ganges-Brahmaputra-Meghna basins using Flood Duration Curves (FDCs) and Drought Duration Curves (DDCs). Duration curves are drawn for monthly basin-averaged precipitation over each of the three basins and daily streamflow at their outlets for three periods: the observed (1980–2009), the near-future (2015–2039) and the far-future (2075–2099). Degree of difficulty of managing hydrological extremes is measured in terms of difficulty of smoothing hydrological variations which can be identified from the duration curves. Among three basins the manageability of the Meghna basin is expected to be more difficult due to increases of seasonal and annual variations of streamflow in the future. Significantly distinct persistence characteristics have been identified, which can be utilized for flood control, reservoir design and operation. The information contained in these curves has direct implications on policy making for future water resources development and water resources management both in flood and drought.