The primary objective of the interdisciplinary GLOWA Volta Project (GVP) is to provide an analysis of the physical and socio-economic determinants of the hydrological cycle within the Volta Basin in the face of global and regional environmental change. The corresponding primary output will take the form of a scientifically sound and adequately tested Decision Support System (DSS) for the assessment, sustainable use and development of the Basin’s water resources. The DSS will provide a comprehensive monitoring and simulation framework, enabling decision makers to evaluate the impacts of climatic and land use trends with particular emphasis on the consequences of deliberate policies, investments and other interventions for the social, economic and biological productivity of water resources. A vital precondition for the success of this effort is the development of scientific capacity and infrastructure within the Basin to ensure the self-sustainability of the DSS.
During the first phase of the GLOWA Volta Project (GVP), priorities included the establishment of research infrastructure and the collection of climatic, hydrologic, environmental and socioeconomic data, which are scarce within the Volta Basin. A large number of focused studies, many conducted by Ph.D. trainees from the Volta region, attempted to bridge gaps in spatial and temporal scales as solutions to the problems of data scarcity. Phase I also encompassed the establishment of working relationships between European GVP partners and counterparts in Ghana. During Phase II, modeling activities predominated. Mesoscale climate models (MM5) were successfully linked with physical hydrology models (WaSIM-ETH) at catchment, tributary and full basin scales. Numerous anthropologic and socioeconomic studies were successfully completed, creating databases from which a range of household models of socioeconomic behavior were identified. Phase III activities will focus on integration of Phase I and II outputs, emphasis on aggregate economic analysis, operationalization of DSS components and transfer of activities and responsibilities to institutions within the Volta Basin.
For the project’s third phase (GVP III), four priorities were defined:
Essential continuity with Phase I and II research activities is preserved, but work packages have been re-organized to reflect operational, rather than research requirements. We are replacing the Atmosphere, Land and Water themes that gave structure to GVP research in Phases I and II with themes identified as
The Volta River’s watershed encompasses some of the poorest areas of Africa. GNI per capita is estimated to be $ 320 per year, and rain-fed and some limited irrigated agriculture constitute the principle income source for the majority of the population and the backbone of the largely rural societies. Population growth rates are high, placing increasing pressure on land and water resources. In Ghana, for example, it is estimated that only 10.3 million (51 percent) of its 20 million inhabitants have access to safe water.
Improved agricultural production in the West African savannah will depend on the development and effective use of surface and near-surface water resources. Irrigation and water resources development programs, if implemented on a large scale, will have impacts on the availability of downstream water resources, in particular on inflows to the Volta Reservoir, on which Ghana’s urban population depends for power generation. Such developments may also place increasing stress on aquatic ecosystems dependant on seasonal flow regimes.
Precipitation within the region is highly variable, resulting in the periodic occurrence of droughts, and unpredictable rainfall is a major factor in the economic justification for investment in hydraulic infrastructure such as Akosombo Dam. Even the presence of such massive infrastructure does not render the basin invulnerable to drought and its impacts, however, as witnessed by the power shortages which plagued Ghana in 1998 following an extended period of unusually low rainfall. All proposed water resources management strategies will have to be evaluated on the basis of a thorough understanding of climatic variability, and of long-term patterns of change in climate.
Land use practices affect the hydrological cycle, and large-scale alterations in land use patterns apparently possess the capacity to induce changes in weather patterns and rainfall characteristics within the basin, although the causal linkages are extremely complex. Future West African climatic regimes will also be affected by global climate change. There is at present only limited understanding of the impact of global changes on meso-regions such as West Africa, and even less knowledge on the feed-back mechanisms between global climate change, regional weather-determining factors such as land-cover changes and the resulting shifts in evaporation and run-off. Significant alterations to this complex system may have disastrous consequences for the region and may affect both water availability, and the range of strategies available for managing this precious resource.