Assessing the impacts of climate change on climatic extremes in the Congo River Basin

• DOI: 10.1007/s10584-022-03326-x
• Publication Date: 2022-02-28T05:02:26Z
• Authors: Sara Karam; Ousmane Seidou; Nidhi Nagabhatla; Duminda Perera; Raphael M. Tshimanga
• Keywords: Representative Concentration Pathways

The Congo River Basin, located in central Africa, is the second-largest river basin world, after Amazon. It has a drainage area of approximately 3.7 M km2 and home to 75 million people. A significant part population exposed recurrent floods droughts, climate change likely worsen these events. Climate studies have so far focused on annual seasonal precipitation, but little attention was paid extreme climatic This study aims assess future changes rainfall-induced flash drought regimes from present day 2100, using four selected indices as proxies two natural disasters. are total precipitation (PCPTOT), number days where rainfall above 20 mm (PCP20), standardized index (SPI), precipitation-evapotranspiration (SPEI). were calculated with statistically downscaled output eleven Regional Models (RCMs) Coordinated Downscaling Experiment (CORDEX-AFRICA) under Representative Concentration Pathways: RCP 8.5 (high emissions scenario) 4.5 (moderate scenario). Precipitation temperature simulated by RCMs quantile mapping, while wind speed, solar radiation, relative humidity projected K-nearest neighbor downscaling. evolution then assessed between reference period (1976-2005) three periods (2011-2040, 2041-2070, 2071-2100). Multimodel average results suggest that (i) independently scenario period, PCPTOT SPI will increase north, east, western extremities decrease basin's center. (ii) maximum (+ 24%) (- 6%) both 2071-2100 period. (iii) PCP20 scenario. Under 8.5, 94% over whole watershed. (iv) SPEI all scenarios, rise evapotranspiration due higher temperatures offset increases basin. Increased evaporation exacerbate center, leading increased frequency entire basin.The online version contains supplementary material available at 10.1007/s10584-022-03326-x.