10.07.2015 Views

African Water Development Report 2006 - United Nations Economic ...

African Water Development Report 2006 - United Nations Economic ...

African Water Development Report 2006 - United Nations Economic ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

FRESHWATERRESOURCES INAFRICAThe main climatic mechanism that influencesmoisture input into Africa is the movement ofthe Inter-Tropical Convergence Zone (ITCZ)over the continent. Seasonal rainfall over Africais basically attributed to the position of theInter-Tropical Front which together with thestrengths of the southwesterly monsoons and theupper easterly air currents, accentuated by localphysiographic and orographic conditions, determinethe direction and amounts of the rains.For example, rainfall is expected in the southernparts below 10°N around March-April, whilethe regions up to 20°N receive rain from June-September. Generally, Africa is characterized byextreme climatic zones; from humid equatorialand tropical zones through the semi-arid to thearid North, creating about seven distict hydroclimaticzones (table 4.1). The distribution ofrainfall over Africa therefore exhibits extremeunevenness, both spatially and temporally.FRESHWATER RESOURCES IN AFRICAFigure 4.1: Current vs Mean Position of the Africa ITCZ, as analyzed by the NDAAClimate Prediction Centre ( June 2005 Dekad 2)Source: NWS, 200553

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!