Pseudo global warming experiment of flood inundation in the upper White Volta River, Ghana

Abstract

Study area: Upper White Volta River Study focus: Hydro-meteorological inundation models were applied to simulate an extreme river flood that occurred in the upper White Volta River in September of 2020. The predicted inundation area was in good agreement with the flood area estimated by Sentinel-1A SAR. In addition, pseudo global warming (PGW) simulations using the SSP5–8.5 (Shared Socio-economic Pathway 5–8.5) scenario according to IPCC AR6 were conducted to evaluate the extreme rainfall and associated inundation area under warmer environmental conditions. New hydrological insights for the region: As a result of simulations, the average future rainfall intensity is likely to increase mainly due to higher relative humidity in the regional atmosphere. Associated with these changes, it is likely that the extent of the ensemble average future expected flooded area in the upper White Volta River could slightly increase by 1.04 times under the PGW conditions, compared with present climate conditions. The result of this study implies that floods in the upper White Volta River have the potential of becoming more severe under the most extreme future global warming scenarios.

Keywords

• PGW experiment
• SSP5–8.5 scenario
• WRF-Hydro
• Nays 2D Flood