Title: Climate change and its impact on streamflow in the upper Blue Nile River Basin, Ethiopia

Authors: Gizachew Kassa; Ayenew Dessalegn; Anirudh Bhowmick

Addresses: Faculty of Meteorology and Hydrology, Arba Minch Water Technology Institute, Arba Minch University, Ethiopia ' Faculty of Meteorology and Hydrology, Arba Minch Water Technology Institute, Arba Minch University, Ethiopia ' Faculty of Meteorology and Hydrology, Arba Minch Water Technology Institute, Arba Minch University, Ethiopia

Abstract: To reduce uncertainty in climate projection and accompanied stream flow prediction, three CMIP5 climate models ensemble mean outputs of baseline and scenarios (RCP4.5 and 8.5) combined with HEC-HMS4.2 hydrological modelling of three large sub-basins were applied to estimate impact of climate change on streamflow of upper Blue Nile River Basin, Ethiopia. Mean annual, seasonal climate and streamflow changes were assessed for each sub-basin. Rainy season (June to September) precipitation becomes enhanced, while it becomes reduced during other seasons, hence mean annual decreased relative to historical. Average wet and dry season runoff change ranges from +67% to −52.16% and +62.6% to −59% under RCP4.5 and RCP8.5 during the mid-term (2050s), while during long-term (2080s) changes from +61.3% to −57% and +78.3% to −53.6% across three sub-basins. The projected mean annual streamflow showed a decrement of 10.6% for Kesse and Belles sub-basins and an increment of up to 25% for Didessa sub-basin.

Keywords: climate change; streamflow; water resource; Blue Nile River Basin.

DOI: 10.1504/IJHST.2024.137777

International Journal of Hydrology Science and Technology, 2024 Vol.17 No.3, pp.278 - 297

Received: 30 Oct 2021
Accepted: 11 Aug 2022
Published online: 05 Apr 2024 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article