Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.936 IF 4.936
  • IF 5-year value: 5.615 IF 5-year
    5.615
  • CiteScore value: 4.94 CiteScore
    4.94
  • SNIP value: 1.612 SNIP 1.612
  • IPP value: 4.70 IPP 4.70
  • SJR value: 2.134 SJR 2.134
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 107 Scimago H
    index 107
  • h5-index value: 63 h5-index 63
Volume 21, issue 8
Hydrol. Earth Syst. Sci., 21, 4115–4130, 2017
https://doi.org/10.5194/hess-21-4115-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Hydrol. Earth Syst. Sci., 21, 4115–4130, 2017
https://doi.org/10.5194/hess-21-4115-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 16 Aug 2017

Research article | 16 Aug 2017

Simulated hydrologic response to projected changes in precipitation and temperature in the Congo River basin

Noel Aloysius1,a and James Saiers1 Noel Aloysius and James Saiers
  • 1School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
  • anow at: Department of Food, Agriculture & Biological Engineering and Aquatic Ecology Laboratory, Department of Evolution, Ecology and Organismal Biology, Ohio State University, Columbus, OH, USA

Abstract. Despite their global significance, the impacts of climate change on water resources and associated ecosystem services in the Congo River basin (CRB) have been understudied. Of particular need for decision makers is the availability of spatial and temporal variability of runoff projections. Here, with the aid of a spatially explicit hydrological model forced with precipitation and temperature projections from 25 global climate models (GCMs) under two greenhouse gas emission scenarios, we explore the variability in modeled runoff in the near future (2016–2035) and mid-century (2046–2065). We find that total runoff from the CRB is projected to increase by 5 % [−9 %; 20 %] (mean – min and max – across model ensembles) over the next two decades and by 7 % [−12 %; 24 %] by mid-century. Projected changes in runoff from subwatersheds distributed within the CRB vary in magnitude and sign. Over the equatorial region and in parts of northern and southwestern CRB, most models project an overall increase in precipitation and, subsequently, runoff. A simulated decrease in precipitation leads to a decline in runoff from headwater regions located in the northeastern and southeastern CRB. Climate model selection plays an important role in future projections for both magnitude and direction of change. The multimodel ensemble approach reveals that precipitation and runoff changes under business-as-usual and avoided greenhouse gas emission scenarios (RCP8.5 vs. RCP4.5) are relatively similar in the near term but deviate in the midterm, which underscores the need for rapid action on climate change adaptation. Our assessment demonstrates the need to include uncertainties in climate model and emission scenario selection during decision-making processes related to climate change mitigation and adaptation.

Publications Copernicus
Download
Short summary
With the aid of a hydrological model and outputs from global climate models (GCMs), we elucidate the spatiotemporal variability of rainfall–runoff in the Congo River basin in the past and in the future under multiple greenhouse gas emission scenarios. We show that the hydrologic model that is forced with outputs from 25 GCMs and two emission scenarios reveal a range of projected changes in precipitation and runoff, and that runoff dynamics are highly sensitive to GCM forcing.
With the aid of a hydrological model and outputs from global climate models (GCMs), we elucidate...
Citation