Editorial: Setting the Scene-Hydropolitics and the Development of the South African Economy

摘要

South Africa is a complex country with a history that is as rich as it is convoluted (Van Vuuren et al, 2007). Significantly, it has an industrialized economy, and is also one of the most economically diverse, water-scarce countries in the world, its population having adapted well to the largely semi-arid climate. This fact, in addition to the fundamental vulnerabilities that characterize South Africa's aquatic ecosystems, needs to be understood by the new generation of water resource managers if they are to engage successfully in sustainable and effective water management. A defining feature of South Africa is that it is part of a region that has the lowest conversion of mean annual precipitation (MAP) to mean annual runoff (MAR) in the world, a characteristic shared only with Australia (McMahon, 1979; O'Keeffe et al., 1992). The continental average for the conversion of MAP to MAR is 20%, i.e. one-fifth of the water that falls as rain eventually ends up as streamflow, a fact that is skewed because of the tropics at the centre of the continent. Most of the southern African region ranges from 10% to 15% MAP to MAR conversion, while the rest falls considerably below this key-defining ratio. Rivers with such a low conversion ratio are known as ephemeral streams and are episodic in nature with unique ecosystems and management challenges of their own (Jacobsen et al., 1995; Pallet et al., 1997; Seeley et al., 2002). In the case of South Africa, economic growth and development is fundamentally constrained by water resource availability as the country only has an average annual precipitation of 480 mm. This is a startling fact when one takes into account that in 2004 approximately 98% of the national water resource had already been allocated at a high assurance of supply level (NWRS, 2004). This situation leaves little margin for error if sustained economic growth is to be the norm in future.