Abstract
The Nile basin is the second largest basin in Africa and one of the regions experiencing high climatic diversity with variability of precipitation and deteriorating water resources. As climate change is affecting most of the hydroclimatic variables across the world, this study assesses whether historical changes in river flow and sediment loads at selected gauges in the Nile basin can be attributed to climate change. An impact attribution approach is employed by constraining a process-based model with a set of factual and counterfactual climate forcing data for 69 years (1951–2019), from the impact attribution setup of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a). To quantify the role of climate change, we use the non-parametric Mann-Kendall test to identify trends and calculate the differences in long-term mean annual river flow and sediment load simulations between a model setup using factual and counterfactual climate forcing data. Results for selected river stations in the Lake Victoria basin show reasonable evidence of a long-term historical increase in river flows (two stations) and sediment load (one station), largely attributed to changes in climate. In contrast, within the Blue Nile and Main Nile basins, there is a slight decrease of river flows at four selected stations under factual climate, which can be attributed to climate change, but no significant changes in sediment load (one station). These findings show spatial differences in the impacts of climate change on river flows and sediment load in the study area for the historical period.
| Original language | English |
|---|---|
| Article number | 42 |
| Number of pages | 21 |
| Journal | Climatic Change |
| Volume | 177 |
| Early online date | 26 Feb 2024 |
| DOIs | |
| Publication status | E-pub ahead of print - 26 Feb 2024 |
Bibliographical note
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Funding
The authors thank the Research Foundation \u2013 Flanders (FWO) for funding the International Coordination Action (ICA) \u201COpen Water Network: Open Data and Software tools for water resources management\u201D (project code G0E2621N), the EU H2020 programme for funding \u201CWater-ForCE \u2013 Water scenarios For Copernicus Exploitation\u201D (grant agreement No. 101004186), the EU H2020-MSCA-ITN-2020 project InventWater \u201CInventive forecasting tools for adapting water quality management to a new climate\u201D (grant agreement 956623) and the King Baudouin Foundation for the Ernest du Bois Fund (agreement No. 2022-F2812650-228938).
| Funders | Funder number |
|---|---|
| Fonds Wetenschappelijk Onderzoek | |
| Horizon Europe | 101004186 |
| King Baudouin Foundation | 2022-F2812650-228938 |
Keywords
- Impact attribution
- Africa
- Climate change
- SWAT+
