Accra: Water research scientists have highlighted significant increases in extreme weather conditions in the Pra River Basin, with marked rises in both extreme rainfall and temperature indices over recent decades, particularly between 2011 and 2020.
According to Ghana News Agency, Dr. Emmanuel Obuobie, Principal Investigator of the Building Climate-Resilience into Basin Water Management (CREAM) Project, reported that these developments pose heightened risks to water security, agriculture, health, and ecosystems in the region.
The study underscores the urgent need to revise and implement Integrated Water Resources Management (IWRM) strategies within the basin to mitigate the impacts of increasing climate extremes. Dr. Obuobie emphasized the importance of adapting to these changes to enhance resilience across various sectors, including water management, agriculture, and environmental conservation. He provided a comprehensive spatiotemporal analysis of past and future precipitation and temperature extremes, crucial for sustainable water resource management.
Research scientists from the Water Research Institute of the Council for Scientific and Industrial Research (CSIR-WRI) have been actively engaging stakeholders through the Danish-funded CREAM Project. This initiative, which includes a consortium of nine partners led by CSIR-WRI, focuses on building climate resilience into basin water management in Ghana, specifically in the Pra and Densu River Basins. The project employs thirteen WMO-recommended indices to assess historical and projected changes in climate extremes.
A concept note from the project details the analysis of simulations from four CORDEX-Africa regional climate models under RCP4.5 and RCP8.5 scenarios for future periods. These include near-term (2026-2045), mid-century (2046-2065), and late-century (2066-2100) projections relative to a 1991-2020 baseline. Historical trends were derived from high-resolution data developed under the project, which is set to continue until 2025.
Dr. Obuobie noted a doubling in the intensity of rainfall events over the past decade and projected these trends to persist. The CREAM Project has facilitated the development of tools and data that promote dialogue among stakeholders for inclusive and data-informed water governance. The project aims to integrate climate change scenarios, land use, and socio-economic pathways into water management practices.
Mr. Mark Osei-Owusu, a Principal Technologist at the Surface Water Division of CSIR-WRI, warned of increased flood risks due to land use and cover degradation. His work on the CREAM Project involves modeling the impact of climate and land use changes on the hydrology of the Pra River Basin using the SWAT Model. This research highlights the need for integrated studies of climate and land use changes for effective water management.
The Water Resources Commission has identified human disturbances as a significant factor causing extensive ecosystem variations in the Pra River Basin. The SWAT model's hydrological simulations indicate a continuous increase in cropland, settlement, and mining activities, negatively impacting forest areas.
The Pra River Basin, located in southwestern Ghana, covers an area of 23,200 km² and is renowned for its mining activities. It features a bimodal rainfall pattern and a mean annual discharge of 214 cubic meters per second, with temperatures ranging from 25° to 27°C.