Climate Change Impact on Haor Flooding in Bangladesh Using Three Global Circulation Models

The study presents the possibilities of climate change and their potential impacts on the flooding regime at Haor area of Bangladesh. The possible changes in the magnitude of flood were assessed using a hydrological and 1-D hydrodynamic model. Climate change scenarios were constructed from the results of three General Circulation Models (GCMs)-ECham5, CSIRO-Mk3.5 and MIROC3.2 (medres) with the B1 and A2 IPCC scenarios for 2050 and 2090. Different GCMs predict an increase in precipitation in the Haor area. The study also reveals an increase in peak discharge in the major rivers at the Haor area. The pre-monsoon flood peak discharge and water level are predicted to increase significantly compared to the monsoon peak and water level. A flood index was developed for 2050 with the predicted hydrograph. It is predicted that the flood severity would increase most of the rivers in the deeply flooded area of Haor. Further study considering the entire Haor area of Bangladesh is necessary to further investigate the flooding characteristics and the impact of climate change.