Water stress sensitivity index (2010) - ClimAfrica WP4

The “water stress index” relates to the water sensitivity of a certain area in 2010. This potential is measured the water consumption and its relation to water availability and by the volume of rainfall available per people in crop land areas. The index results from the third cluster of the Principal Component Analysis preformed among 16 potential variables. The analysis identify two dominant variables, namely “water consumption per capita” and “water stress”, assigning respectively the weights of 0.58 and 0.42. Before to perform the analysis the variable “water consumption per capita” were log transformed to shorten the extreme variation. All the variables were score-standardized (converted to distribution with average of 0 and standard deviation of 1) in order to be comparable. Three 30 arc-minute grids “water consumption” (industrial, agriculture and domestic) of 2000, produced by World Water Development Report II, were sampled at 0.5 arc-minute and then summed and divided by population to calculate the level of water consumption per capita. The 0.5 arc-minute grid “water stress” were computed dividing the water consumption by the water availability (The 6 arc-minute grid “water availability per capita” of 2005 was computed by sum of the run-off and discharge grids produced by World Water Development Report II and then sampled at 0.5 arc-minutes. A focal statistic ran with a radius of 55 cells (about 50 Km). This had a smoothing effect and represents some of the extend influence of major rivers as a resources for local people). The “water consumption per capita” is an indicator of sensitivity because areas with large water consumption are more sensitive to future water shortage. The “water stress” identifies which areas are actually facing water deficit and thus likely will suffer water shortage in future due to climate change. This dataset has been produced in the framework of the “Climate change predictions in Sub-Saharan Africa: impacts and adaptations (ClimAfrica)” project, Work Package 4 (WP4). More information on ClimAfrica project is provided in the Supplemental Information section of this metadata.