Modelling in the Semi Arid Volta Basin of West Africa.

Hydrology is the science that deals with the processes governing the depletion and replenishment of water resources of the earth's land areas. The purpose of this book is to put together recent developments on hydrology and water resources engineering. First section covers surface water modeling and second section deals with groundwater modeling. The aim of this book is to focus attention on the management of surface water and groundwater resources. Meeting the challenges and the impact of climate change on water resources is also discussed in the book. Most chapters give insights into the interpretation of field information, development of models, the use of computational models based on analytical and numerical techniques, assessment of model performance and the use of these models for predictive purposes. It is written for the practicing professionals and students, mathematical modelers, hydrogeologists and water resources specialists.

The Volta River is one of the major rivers in Africa. In this study, a dynamic regional climate model (CCLM), a hydrological model (SWAT) and a water resource model (WEAP) were used to provide an assessment of one downscaled ‘middle impact’ climate change scenario on the performance of existing and planned irrigation and hydropower schemes. The results indicate that, by the middle of the twenty-first century, altered climate is likely to undermine the technical performance of existing and planned reservoirs, which will, in turn, affect development outcomes. Future water resources development in the basin requires interventions that bolster resilience and water security. Much more systematic planning of water storage, greater cooperation between the riparian states and consideration of innovative approaches to water storage are needed.

The Volta River Basin (VRB) is an important transboundary basin in West Africa that covers approximately 410,000 square kilometres across six countries: Benin, Burkina Faso, Côte d’Ivoire, Ghana, Mali and Togo. Its natural resources sustain the livelihoods of its population and contribute to economic development. This book provides a comprehensive, interdisciplinary review and assessment of the issues and challenges faced. The authors provide a science-based assessment of current and future scenarios of water availability, the demands of key sectors, including agriculture and hydropower, and the environment under changing demographic, economic, social and climatic conditions. They also identify solutions and strategies that will allow available water resources to be sustainably used to improve agricultural productivity, food security and economic growth in the VRB. Overall, the work examines from a multidisciplinary and multi-stakeholder perspective the solutions and strategies to improve the use of water and other natural resources in the VRB to achieve enhanced food security, livelihoods and economic growth.

"The study presents the analyses of field observations and simulation experiments with an event-based, two-dimensional hydrodynamic model. The model summarized the interactions between temporally dynamic rainfall, infiltration process and surface runoff in a catchment with varied soil physio-hydraulic properties, surface-roughtness, slope-lengths and vegetation structure. Both observation and simulation results indicate that the observation scale affects runoff coefficient and runoff discharge per unit area. The effect of scale is a result of spatial variability in infiltration opportunities, which vary with the slop length and distribution of saturated conductivity, leading to different trasmission losses potential during runoff routing downslope. The magnitude of the difference is influenced by surface and vegetated microtopography, which determine the flow rate"--Back cover.