Rivers of southern Africa

Southern Africa's rivers are diverse, sustaining ecosystems and people. They have tremendous social, ecological, and economic value throughout the region. The rivers in the region are highly variable and grouped into eight large basins/river regions. This chapter reviews the river regions of southern Africa, the main rivers of each region, where and how they flow, how they support people and biodiversity, and how people use and often abuse and manage these important ecosystems. The rivers of southern Africa are highly variable and differ across the region seasonally and in length and size. The biodiversity of the rivers generally increases in a northerly direction from low diversities in the Cape toward the large tropical rivers in central Africa. Endemism of the rivers is inversely proportional to biodiversity trends, with extreme endemism in the Cape decreasing in a northerly direction. The rivers in southern Africa provide us with provisioning and cultural services including food and places for spiritual and recreational activities. These rivers also provide important regulatory services, processing and assimilating waste, and buffering us and biodiversity from sudden changes in environmental conditions. The present socioecological state of the rivers in southern Africa varies throughout the region from good to poor condition, and in the region, multiple stressors associated with urbanization, mining and industrial development, and intensive agriculture generally drive water quantity and quality impacts. Most of the rivers in the region had been altered by anthropogenic stressors prior to the global drive for sustainability. Today, the Southern African Development Community recognize the importance of sustainability and are establishing policies and regional plans to address the equitable access to water resources and support their sustainable development in the region. The rivers throughout the region are being developed; we need to understand what they need and how to develop these rivers in a sustainable way. The river ecosystems need us to look after them and to use them sustainably and for active rehabilitation/protection efforts. The 20th century has globally been celebrated as a period of human development; let the 21st century become the period of sustainable use and protection for the benefit of freshwater ecosystems and their people in southern Africa.