The Volta Basin Water Allocation System: assessing the impact of small-scale reservoir development on the water resources of the Volta basin, West Africa

摘要

In the Volta Basin, infrastructure watershed development with respect to theimpact of climate conditions is hotly debated due to the lack of adequatetools to model the consequences of such development. There is an ongoingdebate on the impact of further development of small and medium scalereservoirs on the water level of Lake Volta, which is essential forhydropower generation at the Akosombo power plant. The GLOWA Volta Project(GVP) has developed a Volta Basin Water Allocation System (VB-WAS), adecision support tool that allows assessing the impact of infrastructuredevelopment in the basin on the availability of current and future waterresources, given the current or future climate conditions. The simulatedhistoric and future discharge time series of the joint climate-hydrologicalmodeling approach (MM5/WaSiM-ETH) serve as input data for a river basinmanagement model (MIKE BASIN). MIKE BASIN uses a network approach, andallows fast simulations of water allocation and of the consequences ofdifferent development scenarios on the available water resources. The impactof the expansion of small and medium scale reservoirs on the stored volumeof Lake Volta has been quantified and assessed in comparison with the impactof climate variability on the water resources of the basin.