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. 2023 Jun 28;18(6):e0287314.
doi: 10.1371/journal.pone.0287314. eCollection 2023.

The impacts of climate change on hydrological processes of Gilgel Gibe catchment, southwest Ethiopia

Zewde Alemayehu Tilahun  1 , Yechale Kebede Bizuneh  1 , Abren Gelaw Mekonnen  1
Affiliations

The impacts of climate change on hydrological processes of Gilgel Gibe catchment, southwest Ethiopia

Zewde Alemayehu Tilahun et al. PLoS One. .

Abstract

Climate change is a significant driver of water resource availability, affecting the magnitude of surface runoff, aquifer recharge, and river flows. This study investigated the impact of climate change on hydrological processes within the Gilgel Gibe catchment and aimed to determine the level of exposure of water resources to these changes, which is essential for future adaptability planning. To achieve this objective, an ensemble mean of six regional climate models (RCMs) from the coordinated regional climate downscaling experiment (CORDEX)-Africa was used to simulate future climatic scenarios. The RCMs outputs were then bias corrected using distribution mapping to match observed precipitation and temperature. The Soil and Water Assessment Tool (SWAT) model was used to assess the hydrological impacts of climate change on the catchment. The results indicated that the ensemble mean of the six RCMs projects a decline in precipitation and an increase in temperature under both the RCP4.5 and RCP8.5 representative concentration pathways. Moreover, the increases in both maximum and minimum temperatures are higher for higher emission scenarios, indicating that RCP8.5 is warmer than RCP4.5. The projected climate change shows a decrease in surface runoff, groundwater, and water yield, resulting in an overall decline of annual flow. This decline is mainly due to the reduction in seasonal flows driven by climate change scenarios. The changes in precipitation range from -11.2% to -14.3% under RCP4.5 and from -9.2% to -10.0% under RCP8.5, while the changes in temperature range from 1.7°C to 2.5°C under RCP4.5 and from 1.8°C to 3.6°C under RCP8.5. These changes could lead to reduced water availability for crop production, which could be a chronic issue for subsistence agriculture. Additionally, the reduction of surface water and groundwater could further exacerbate water stress in the downstream areas, affecting the availability of water resources in the catchment. Furthermore, the increasing demands for water, driven by population growth and socioeconomic progress, along with the variability in temperature and evaporation demands, will amplify prolonged water scarcity. Therefore, robust climate-resilient water management policies are indispensable to manage these risks. In conclusion, this study highlights the importance of considering the impact of climate change on hydrological processes and the need for proactive adaptation measures to mitigate the impacts of climate change on water resources.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Location and elevation map of study area.
Fig 2
Fig 2. The dominant soils of Gilgel Gibe catchment.
Fig 3
Fig 3. Average monthly rainfall of the selected stations.
Fig 4
Fig 4. Monthly maximum and minimum temperature of the selected stations.
Fig 5
Fig 5. Flowchart of ArcSWAT processing steps for the Gilgel Gibe catchment.
Fig 6
Fig 6. Sub-watersheds of the Gilgel Gibe catchment.
Fig 7
Fig 7. Precipitation and temperature recording stations.
Fig 8
Fig 8. Drainage in Gilgel Gibe catchment.
Fig 9
Fig 9. Gilgel Gibe catchment river discharge gauging stations.
Fig 10
Fig 10. Calibration and validation of average monthly streamflow.
Fig 11
Fig 11. Percentage change of projected average precipitation in Gilgel Gibe catchment for 2041–2070 and 2071–2099 under RCP4.5 and RCP8.5.
Fig 12
Fig 12. Seasonal projected change in mean maximum temperature in Gilgel Gibe catchment for 2041–2070 and 2071–2099 under RCP4.5 and RCP8.5.
Fig 13
Fig 13. Seasonal projected change in mean minimum temperature in Gilgel Gibe catchment for 2041–2070 and 2071–2099 under RCP4.5 and RCP8.5.
Fig 14
Fig 14. Impacts of climate change on water balance.
Fig 15
Fig 15. Spatial patterns of the changes in surface runoff due to climate change.
Fig 16
Fig 16. Spatial patterns of the changes in groundwater due to climate change.
Fig 17
Fig 17. Spatial patterns of the changes in water yield due to climate change.
Fig 18
Fig 18. Spatial patterns of the changes in Potential Evapotranspiration (PET) due to climate change.
See this image and copyright information in PMC

References

    1. Kasperson J. X., Kasperson R. E., Turner B. L., Hsieh W., & Schiller A. (2022). Vulnerability to global environmental change. In The social contours of risk (pp. 245–285). Routledge.
    1. Ribeiro K., Pacheco F. S., Ferreira J. W., de Sousa‐Neto E. R., Hastie A., Krieger Filho G. C., et al. (2021). Tropical peatlands and their contribution to the global carbon cycle and climate change. Global Change Biology, 27(3), 489–505. doi: 10.1111/gcb.15408 - DOI - PubMed
    1. Al‐Ghussain L. (2019). Global warming: Review on driving forces and mitigation. Environmental Progress & Sustainable Energy, 38(1), 13–21.
    1. IPCC. (2021). Sixth Assessment Report (AR6). Intergovernmental Panel on Climate Change. https://www.ipcc.ch/report/ar6/
    1. Lindersson S., Brandimarte L., Mård J., & Di Baldassarre G. (2020). A review of freely accessible global datasets for the study of floods, droughts and their interactions with human societies. Wiley Interdisciplinary Reviews: Water, 7(3), e1424.