Africa: climate change will seriously affect surface water supply, predict researchers

Climate change will significantly affect present surface water access across 25% of Africa by 2100, with some rivers drying up completely, warn South African researchers [1]. They stress the need for effective water management systems across the continent, especially in vulnerable rural areas which do not have the same resources to deal with drought as large cities.

By studying the relationship between drainage and rainfall, the researchers predicted which regions would be most affected by a drop in rainfall. For instance in regions receiving 500 mm of rain per year, a 10% drop would result in a 50% cut in surface drainage. The densely populated regions of southern Africa, large sections of the upper Nile and most of East Africa are "of particular concern" the researchers said.

For the South African city of Johannesburg, the researchers estimate that the ten per cent drop in annual rainfall predicted by climate models would reduce the surface water in rivers by nearly 20 per cent. In places such as Jendouba, Tunisia, or Tulear in Madagascar, the predicted ten per cent drop would dry up rivers entirely.

In related news the UN World Food Programme (WFP) announced that AXA Re has been awarded the world’s first insurance contract for humanitarian emergencies. The initiative is especially aimed at supporting poor farmers at risk of drought in sub-Saharan Africa.

[1] De Wit, M. and Stankiewicz, J. (2006). Changes in surface water supply across Africa with predicted climate change. Science. Publ. online 2 Mar 2006. DOI: 10.1126/science.1119929

Web site: Co-operative Programme on water and climate

Contact : Maarten de Wit, AEON - Africa Earth Observatory Network, University of Cape Town, South Africa, maarten@cigces.uct.ac.za, http://web.uct.ac.za/depts/cigces/maarten1.htm

Source: Catherine Brahic, SciDev.Net, 3 Mar 2006 ; WFP, 6 Mar 2006

Keywords

• Water resources management