1. Osborne 2000

2. Hydrology and Water Budgets P n + S i + G i = ET + S o + G o + ΔV

3. http://people.cas.sc.edu/carbone/modules/mods4car/africa-itcz/index.html The Intertropical Convergence Zone, or ITCZ, is the region near the equator where the trade winds of the Northern and Southern Hemispheres come together. The intense sun and warm water of the equator heats the air in the ITCZ, raising its humidity and causing it to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Variation in the location of the ITCZ drastically affects rainfall in tropical regions, resulting in the wet and dry seasons. Longer term changes in the ITCZ can result in severe droughts or flooding.

4. Talling and Lemoalle (1998)

5. Payne (1986)

6. Talling and Lemoalle (1998)

8. Tonle Sap, Mekong River system, Cambodia

9. Lake Chad

10. 31 Oct 1963Jan 1973 Jan 1987Jan 1997

11. M above Bol (278 m above sea level) Year Source: U.S.G.S. Reconstructed water levels based on Nile discharge data drought Start of southern Chad irrigation project

12. Jan 1997 Nigeria's Southern Chad Irrigation Project [the lake level affects irrigation more than v.v.] 19722007

13. Black water Rio Negro and white water Rio Solimoes, lowland Amazonia near Manaus)