Africa, the cradle of many old civilizations, is the second largest world continent, and the homeland of nearly one-eighth of the world population. Despite Africa's richness in natural resources, the average income per person, after excluding a few countries, is the lowest all over the world, and the percentage of inhabitants infected with contagious diseases is the highest.Development of Africa to help accommodate the ever-increasing population and secure a reasonable living standard to all inhabitants, though an enormous challenge is extremely necessary. Water is the artery of life, without it all living creatures on earth cannot survive. As such, a thorough knowledge of the meteorological and hydrological processes influencing the yield and quality of the water resources, surface and subsurface, and their distribution and variability in time and space is unavoidable for the overall development of any part of the world. It is highly probable that the said knowledge is at present a top priority to Africa, a continent that has been for so long-and probably still-devastated by the endless ambitions of colonial powers not to forget the corruption and destruction practiced by the internal powers, at least in some countries.The present book "Hydrology and Water Resources of Africa" is written with the aim of bringing together in one volume a fair amount of knowledge any professional involved in hydrology and water resources of Africa needs to know. African hydrology, after all, covers a wide range of subdivisions ranging from Hyper-arid and arid (Saharan) to very humid (Tropical). With this aim in mind, the material covering the book is distributed among fourteen chapters. The first chapter, as usual, serves as a general introduction. The second, third, fourth and fifth chapters outline and discuss the basic items relevant to climate such as precipitation, evaporation and evapotranspiration. These four chapters are presented from the angle of applied climatology rather than theoretical meteorology.Chapter 6 deals with the processes of runoff and streamflow. Such processes combined with the contents of Chapters 2 to 5 help elaborate a reasonable estimate of the water balance of each of the main hydrologic sub-systems of the continent. Chapters 7 and 8 deal with hydrology of large river basins in East and West Africa, and Central and Southern Africa respectively. Certain aspects of hydrological interest concerning intermediate and small river basins, including ephemeral streams (wadis), are outlined and discussed in Chapter 9.The built-up of Africa includes some areas of wetlands in the form of permanent and seasonal swamps, marshes, and floodplains. The Great Rift Valleys already formed as a result of the tectonic movements and volcanic activities during the Miocene era have created depressions and lakes of depths up to 1,000 m. The volumes of the African Lakes are about eleven times as vii viii PREFACE xv
