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Modeling blue and green water availability in Africa
Author(s) -
Schuol Jürgen,
Abbaspour Karim C.,
Yang Hong,
Srinivasan Raghavan,
Zehnder Alexander J. B.
Publication year - 2008
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2007wr006609
Subject(s) - groundwater recharge , environmental science , evapotranspiration , water scarcity , soil and water assessment tool , aquifer , water resources , hydrology (agriculture) , water resource management , water security , scarcity , water flow , water use , groundwater , environmental engineering , streamflow , geography , engineering , ecology , geotechnical engineering , drainage basin , cartography , economics , biology , microeconomics
Despite the general awareness that in Africa many people and large areas are suffering from insufficient water supply, spatially and temporally detailed information on freshwater availability and water scarcity is so far rather limited. By applying a semidistributed hydrological model SWAT (Soil and Water Assessment Tool), the freshwater components blue water flow (i.e., water yield plus deep aquifer recharge), green water flow (i.e., actual evapotranspiration), and green water storage (i.e., soil water) were estimated at a subbasin level with monthly resolution for the whole of Africa. Using the program SUFI‐2 (Sequential Uncertainty Fitting Algorithm), the model was calibrated and validated at 207 discharge stations, and prediction uncertainties were quantified. The presented model and its results could be used in various advanced studies on climate change, water and food security, and virtual water trade, among others. The model results are generally good albeit with large prediction uncertainties in some cases. These uncertainties, however, disclose the actual knowledge about the modeled processes. The effect of considering these model‐based uncertainties in advanced studies is shown for the computation of water scarcity indicators.