ABSTRACT
This chapter reviews river basin water resource models as applied in the Nile River Basin, distinguishing between simulation, optimization and combined simulation and optimization models. A river basin system consists of water source components and in-stream and off-stream demand components. The conflicts in river system planning and management arise when the water demands of different sectors are supplied from one river system and river flow is less than in-stream and off-stream water requirements. A river can have a single reservoir with one or multiple objectives, or a cascade of reservoirs which are in series and/or in parallel. Water resources simulation models mimic the operation of the system given inflows, system characteristics and operating rules. A spreadsheet based hydro-economic model was developed for the Blue Nile downstream Roseires and Sennar reservoirs in Sudan to trade-off between sedimentation induced losses of storage volume and benefits from hydropower generation and irrigation.
