Predicting the impact of climate change and the hydrological response within the Gurara reservoir catchment, Nigeria

• Published in: Journal of water and land development pp. 129 - 143
• Main Authors: Oseke, Francis Ifie-emi, Anornu, Geophery Kwame, Adjei, Kwaku Amaning, Eduvie, Martin Obada
• Format: Journal Article
• Language: English
• Published: 13-01-2022
• ISSN: 2083-4535; 2083-4535
• DOI: 10.24425/jwld.2021.139023

The 2150 km2 transboundary Gurara Reservoir Catchment in Nigeria was modelled using the Water Evaluation and Planning tool to assess the hydro-climatic variability resulting from climate change and human-induced activities from 1989 to 2019 and projected to the future till 2050. Specifically, the model simulated the historic dataset and predicted the future runoff. The initial results revealed that monthly calibration/validation of the model yielded acceptable results with Nash–Sutcliff efficiency ( NSE), percent bias ( PBIAS), and coefficient of determination (R2) values of 0.72/0.69, 0.72/0.67 and 4.0%/1.0% respectively. Uncertainty was moderately adequate as the model enveloped about 70% of the observed runoff. Future predicted runoffs were modelled for climate ensembles under three different representative concentration pathways (RCP4.5, RCP6.5 and RCP8.5). The RCP projections for all the climate change scenarios showed increasing runoff trends. The model proved efficient in determining the hydrological response of the catchment to potential impacts from climate change and human-induced activities. The model has the potential to be used for further analysis to aid effective water resources planning and management at catchment scale.