ASSESSMENT OF CLIMATE CHANGE IMPACT ON WATER RESOURCES IN THE CONGO RIVER BASIN

Abstract

There is a considerable uncertainty about the future impacts of climate change on the hydrology and water resources systems. The Congo Basin is one of the three core regions of convection in the global tropics, the other two being the Maritime continent of the tropical West Pacific and Eastern Indian Oceans and the Amazon basin. The water resources of the Congo River Basin are crucial to support the socioeconomic development in nine African countries. In this study, the main objective is to assess the impact of climate change on water resources in the Congo River Basin. To achieve the study objective, the required climate change data (rainfall and temperature) are downloaded for the basin using the eight Regional Climate Models (RCMs) of the Coordinated Regional Downscaling Experiment (Cordex Africa). A comparison is undertaken between the observed data for historical period (1951 to 2005) and Cordex- African database (with the GPCC and CRU database) in order to correct the climate change database using bias correction technique. Then a corrected eight average historical models and modified average future climate change models for the two scenarios of RCP (Representative Concentration Pathways) 4.5 and RCP8.5 are obtained. The hydrology regime of the Congo River Basin is simulated through using Rainfall-Runoff software of MIKE Zero (MIKEHYDRO) powered by DHI (Institute for Water and Environment). The historical dataset (1951 to 2005) was used for calibration and validation of MIKE Zero software in order to build future climate change scenarios (2006 to 2100). Each future climate change scenario either RCP4.5 or RCP8.5 was divided into three sub-phases; near future (2006-2040), moderate future (2040-2070), and far future (2070-2100). It was concluded that the climate changes affect the discharge of Congo River significantly during dry and wet season. The average increase in the runoff discharge from tributaries of Congo River ranges from 21% (intermediate future) to 117% (near future), also the average decrease of runoff discharge from tributaries in Congo river ranges from 17% to about 60% at the intermediate future zone.