A continental scale water balance model: a GIS-approach for Southern Africa

摘要: Abstract A distributed GIS-based hydrological model is developed using GIS and computational hydrology techniques. The based on water balance consideration of the surface subsurface processes. processes include precipitation infiltration, overland runoff, evapo-transpiration canopy interception losses daily time steps; process considers soil moisture accounting a monthly basis. was used to estimate generated runoff from matrix specific geo-referenced grids representing Southern Africa. All regional seasonal dispensation balances have been standard formats for storage, spatial display interpretation results. Considering 1961–1990 climatic period, we mapped variation mean annual (SM), actual (AET), (ROF) across Africa or known as SADC region. estimates SM region be about 148 mm/year. There wide range in distribution over due fact that absolute dependent retention properties soils considered prediction AET reaches maximum 1500 mm, with 420 mm. land catchment 151 mm/year although there significant inter-regional among countries, which function vegetation cover, climate variation. Lower regimes are dominant arid areas Botswana, Namibia south-western part Republic South Higher Northern Western Tanzania, along east coastal portions Mozambique, central western Zambia Malawi.