Modelling the potential impacts of climate change on hydrology of the Bago River Basin, Myanmar

Assessment of climate change impacts on the hydrological cycle is important for basin scale water resources development, planning and management. This study aims to investigate the potential impacts of climate change on hydrology of the Bago River Basin (BRB) in Myanmar. Two scenarios from the Representative Concentration Pathways (RCPs): RCP4.5 and 8.5 recommended by the Intergovernmental Panel on Climate Change, Fifth Assessment Report (IPCC AR5) were used to project climate change scenarios for the 2020s, 2050s and 2080s. Six General Circulation Models from the Coupled Model Intercomparison Project Phase 5 were selected to project the climate change scenarios in the basin. An increase of average temperature by 1.5 degrees C and 3 degrees C was observed under RCP4.5 and 8.5 in future periods respectively. Similarly, average annual precipitation shows a distinct increase in all three periods with the highest increase for the 2050s. A well-calibrated and validated Soil and Water Assessment Tool was used to simulate the climate change impact on future stream flows in the basin. Results show the changes in the monthly, seasonal and annual stream flows as compared to baseline period due to the impact of climate change in the basin. The monthly stream flows is projected to increase from May to September in future. The average stream flow changes in the winter season are projected to be higher in comparison to other seasons during 2010-2099. Similarly, the annual and rainy season stream flows are projected to increase approximately 40% and 29% in the whole basin, respectively, while the summer seasonal flows are decreased by 21%. The findings of this study would be helpful to improve water management decisions and in formulating adaptation strategies to reduce the negative impacts, and harness the positive impacts of climate change in the BRB.