Institute for Water Research, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa; Department of Natural Resources Management, University of Kinshasa, P.O. Box 117, Kinshasa, KIN XI, Democratic Republic Congo
Tshimanga, R.M., Institute for Water Research, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa, Department of Natural Resources Management, University of Kinshasa, P.O. Box 117, Kinshasa, KIN XI, Democratic Republic Congo; Hughes, D.A., Institute for Water Research, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa
This study assesses the hydrological response of the Congo Basin's runoff to future changes of climatic conditions. The study is carried out at the sub-basin scale in the northern part of the Congo Basin for which downscaled GCM data have been obtained. In order to assess the impacts of climate change scenarios on water resources availability of the Congo Basin, three downscaled and bias corrected GCMs were used to drive a semi-distributed rainfall-runoff model which was initially established for the whole Congo Basin through manual calibration and physically-based a priori parameter estimation approaches. The analysis focuses on the variables of the hydrological processes such as rainfall, interception, potential evapotranspiration, soil moisture store, surface runoff, soil moisture runoff, and recharge. In general terms, the study shows that there is a decrease in runoff for the near-future projections in the northern part of the Congo Basin which has a tropical transition regime. For the three GCMs used in this study, there is very little change in rainfall from the historical conditions. The major change is observed in evapotranspiration, due to an increase in air temperature. There is a clear indication of the translation of climate signal into flows. There is more than 10% decrease in total runoff, which is a consequence of relatively little increase in rainfall and a consistent increase in potential evapotranspiration. © 2012 Elsevier Ltd.
Air temperature; Climate change scenarios; Climate signals; Climatic conditions; Congo basins; GCMs; Hydrological process; Hydrological response; Manual calibration; Potential evapotranspiration; Priori parameter estimation; Rainfall-runoff models; Sub-basin scale; Subbasins; Surface runoffs; Tropical transition; Water resources availability; Digital storage; Evapotranspiration; Hydrology; Parameter estimation; Rain; Runoff; Soil moisture; Water supply; Climate change; climate change; climate effect; downscaling; evapotranspiration; general circulation model; hydrological response; interception; parameterization; rainfall-runoff modeling; resource availability; runoff; soil moisture; Congo Basin; Ubangi River