Assessing environmental conditions of major river basins in Africa as surrogates for watershed health

There is a growing recognition of the importance of transboundary shared na tural resources. However, with limited resources, international policymaker s need to be able to prioritize regions before allocating resources and add ressing transboundary problems. River basins are perhaps the most natural t ransboundary division and, as such, provide an ecological framework for env ironmental assessments. The health of watersheds that are divided by politi cal boundaries are at particular risk due to differential land management p ractices within each watershed. In Africa, more than any other continent, o ver 60% of the geographical area is a transboundary water-shed. In this art icle, a comparative study of the five major basins in Africa-the Congo, Cha d, Nile, Niger, and Zambezi-has been carried out using consistent geospatia l data sets at l-km resolution. Population, land cover type, and protected areas were used to assess the current status, characteristic differences, a nd impending pressure on river basin resources for each watershed. In addit ion, a focused study within the Nile River basin is used to compare the par ticular differences between countries.