For the rural population of the Volta Basin, rain-fed agriculture supplemented by limited small-scale irrigation forms the primary means of livelihood as well as the major source of income. The annual population continues to grow at around 3 % annually, increasing pressure on land and water resources. Increased agricultural productivity within the African savannah will rely heavily on improved and expanded access to surface- and ground-water resources and on improved water use efficiency.
Reflecting the necessity of sustainable water resources management, the main objective of GLOWA Volta Project phase I (2000 – 2003) was to provide an analysis of the physical and socio-economic determinants of the hydrologic cycle within the Volta Basin. Based on this analysis, a Decision Support System (DSS) will be created to enable the assessment, sustainable use and the development of water resources within the Basin.
The DSS will provide a comprehensive framework for the monitoring and simulation of water resource in space and in time, emphasizing the anticipated influences of climate- and land use changes. This increases decision-makers’ capacity to assess the impacts of factors on the social, economic and ecological productivity of water resources; and to design appropriate land- and water management protocols. The project follows an interdisciplinary approach: in Phase I, 14 sub-projects were organized within three research clusters: Atmosphere, Land Use and Water Use.
Research in the Atmosphere cluster sought to understand, and to simulate the influences of global circulation and land use changes on Basin hydrology. Successful activities completed during Phase I include the development of statistical rules for the up-scaling of land surface parameters, and of algorithms for the calculation of optimal land surface parameterization schemes on the basis of inverse modeling, respectively, required to simulate surface energy fluxes over wide areas. Historical and current trends in precipitation, temperature and river discharge system were evaluated statistically. Simulations using the mesoscale climate model MM5 highlighted the role of for feedback mechanisms between land surface and atmosphere, demonstrating that changes in soil moistness lead to changes in overall precipitation of the same magnitude.
Cluster Land Use
Changes in land use and land cover over the most recent decade were analyzed by means of satellite remote sensing imagery. This imagery was used to develop and test a new statistical method to identify and model regions of rapid, anthropogenically driven land use change, or "hot spots", within the savannah zone.
Cluster Water Use
Methods were developed and tested to use remote sensing imagery to estimate surface discharge, although such methods were ultimately shown to have limited value. By contrast, remote sensing methods were shown to provide highly accurate and timely estimates of storage within the numerous small reservoirs distributed throughout the Upper East Region of Ghana. Regularities between reservoir surface area, which can be observed directly by RS methods, and total storage volume and depth enable RS imagery to provide ”snapshots" of one important component of regional community water supply.
Socio-economic data on Volta Basin inhabitants, their economic activities and their water requirements and uses are scarce, yet indispensable to the design of sound water management protocols. This is an area in which mathematical models are largely incapable of supplying otherwise missing data. During Phase I, GVP designed and implemented a common sampling framework, in which reported data on water use, livelihood and health were linked to the respondents’ immediate physical environment through geo-referencing of interview locations and coordinated sampling and testing of soil and water. Water quality samples were collected from sources actually used by respondents, and soil samples collected from the plots they cultivate, allowing the evaluation of actions, choices and responses in the objective context of physical setting.
Two modeling approaches were developed to evaluate household decision-making and political response: an economic model identifying the determinants of household migration decisions, and an agent-based model to simulate household water and land use.
Research on rural household access to improved water sources within the Volta basin demonstrated that water quality plays a crucial role in household decisions concerning choice of water source. Comparative distances to improved and non- improved water sources act to influence decisions of rural households. For example, well construction decisions can be analyzed using the concept of opportunity cost.
An institutional framework of analysis, including both formal and informal institutions, was constructed to evaluate water resources decision-making from local to national level in Ghana and Burkina Faso. Concurrently, the processes of policy formulation and implementation were analyzed at the national level. This is required to complement research in the natural sciences, since management options are constrained by legal and institutional as well as technical factors. To complicate matters, laws and institutions encompass a range of scales from local to national, multiple stakeholders and a juxtaposition of formal and informal regulations and decision-making frameworks. Within such an environment, resource management decisions are shaped by scientific knowledge and possibly by ecological sustainability, economic efficiency and social justice goals, but also by economic-political interests of actors with bargaining power.
The design and strategy of GLOWA Volta Project Phase II (2003 - 2006) reflect results and experiences acquired in Phase I. Overall project structure, including subdivision into Atmosphere, Land Use and Water Use clusters, is maintained although specific work packages within each cluster have been modified in some cases.
A new cluster, Technical Integration and Decision Support, was added, reflecting the increasingly integrative nature of Project activities. The new cluster addresses the technical requirements involved in coupling models and data developed through discipline-specific research, to support a truly integrated decision support capability. In addition, common sampling frame field survey work initiated in Phase I will be extended, including sites in Burkina Faso. An ingoing scientific-political dialogue with water sector decision-makers within the basin will ensure the policy relevance of Phase II research activities. An example is the White Volta Pilot Project, conducted jointly with the Ghanaian Water Resources Commission (WRC) to test and to introduce integrated water resources management concepts.
Through such cooperation, we prepare for the ultimate transfer of project activities and outputs to partner institutions in Ghana and Burkina Faso during proposed Phase III (2006 – 2009).
While the project Phases I and II were organized along the research clusters “Atmosphere”, “Land use”, and “Water use” to reflect the research foci of the Project, the project structure was re-organized for Phase III to better match the more operational requirements of the third project phase. The structuring of the research clusters and work packages was changed to reflect the priorities placed on the integration of Phase I and II research results, knowledge, data and tools, to set greater emphasis on economic analysis, and to shift the orientation from research to operational modes, emphasizing on the delivery of.
In Phase III, the project was organized along the clusters “Water Supply and Distribution” (Cluster S), “Analysis of Long-Term Environmental Change” (Cluster E), “Water Demand” (Cluster D), “Consortium Building for Technology Transfer” (Cluster C), and “GLOWA Volta Decision Support System” (Cluster I).
The Analysis of Long-Term Environmental Change (E) cluster focuses on environmental changes endogenous to the Volta Basin that evolve over decadal time scales. These changes, such as alterations in land cover, soil degradation and loss of wetlands reflect complex interactions and feedbacks between climate, human settlement and economic activities. Cluster E carries forward much of the work conducted within the previous Land Use cluster.
The Water Supply and Distribution (S) cluster encompasses the analysis of physical water distribution and availability in space and time, inclusive of atmospheric, surface and subsurface hydrologic processes. It contains most of the elements of the previous Atmosphere cluster, runoff and hydraulic routing models, and is extended to include the analysis of climatic and hydrologic phenomena and investigation of groundwater recharge.
The Water Demand and Management (D) cluster consists largely of integrative activities that build extensively on research conducted within Phase II on operations research modeling of water-demanding economic sectors. It integrates Phase II work packages on Water and Livelihood, Institutional Analysis, and some aspects of Technical Integration of Socio-Economic and Environmental Modeling Sub-Systems.
The fourth research cluster is Consortium Building for Technology Transfer (C): The success of the GLOWA Volta Project will ultimately be measured by the continuity of activities within the region following completion of GVP. GVP has built an effective network of partners in Ghana and Burkina Faso, as well as a consortium of international organizations. During Phase III these institutions will progressively assume leadership of project activities and ownership of the project results and outcomes.
The final cluster, GLOWA Volta Decision Support System (I) encompasses technical activities required for the implementation of a scientifically sound DSS. DSS encompass a wide range of scientific simulation tools embodying various methodological approaches and technologies. The primary goal of cluster I is to facilitate the development of an effective, user-friendly DSS infrastructure for water management in the Volta Basin.