Assessment of the Impacts of Proposed Water Resources Development Projects in Baro-Akobo-Sobat Basin on Nile Inflows at High Aswan Dam

Abstract

Study region: The Baro-Akobo-Sobat (BAS) basin, which is a portion of Africa's Eastern Nile Basin (ENB). Study focus: The Baro-Akobo-Sobat (BAS) is one of the four sub-basins in the Eastern Nile Basin (ENB). The Machar Marshes swamp, a wetland in the BAS basin, has significant water losses, which have an impact on the BAS's regional hydrology. Future development initiatives, such as irrigated agriculture and hydropower, are expected to concentrate on the BAS. These initiatives will make a huge contribution to the BAS development, but they may also have a negative impact on the flow of the Nile into downstream countries, which is assessed in this paper. New hydrological insights for the region: The HEC Reservoir Simulation Model (HEC-ResSim) and the Soil Water Assessment Tool (SWAT) model are coupled offline. The BAS modelling system was used to produce the baseline scenario (no anticipated planned development projects) and three additional scenarios (hydropower scenario, irrigation scenario, and integrated scenario between hydropower and irrigation). According to the results, the hydropower scenario increased the flow arriving at Aswan by an average of 1.3 km3/year by reducing losses in marshes due to the controlled flow pattern. The irrigation scenario decreased the flow arriving at Aswan by an average of 4.4 km3/year. The combined hydropower and irrigation development scenario decreased the flow arriving at Aswan by an average of 3.6 km3/year.

Keywords

• Reservoir simulation
• Soil water assessment tool
• Machar Marshes swamp
• Baro Akobo Sobat basin
• Water balance
• System hydrology