Evaluating water scarcity in the Southern African Development Community (SADC) region by using a climate moisture index (CMI) indicator

Increasing water scarcity in the Southern African Development Community (SADC) region has underscored the need to improve our understanding of the management of water resources. Using total evapotranspiration (TET) and precipitation (P) data of the past 16 years this study used a modified version of the climate moisture index (CMI) in order to evaluate water scarcity throughout the SADC region, by examining the relative importance of P and TET on the variability of the CMI. The CMI value for the Democratic Republic of Congo (CMI_DRC = 0.347) as well as for Angola (CMI_Angola = 0.351), ranged between 0.25 and 1, characteristic of a humid region, whereas CMI values for Botswana (CMI_Botswana = 0.027) and South Africa (CMI_{South Africa} = 0.075) ranged between −0.6 and 0 or 0 and 0.25, characteristic of semi-arid to sub-humid regions. Namibia (CMI_Namibia = −0.125) has been experiencing drier conditions. The findings of this linear correlation analysis confirm a strong and significant relationship between DRC-Angola (r = 0.837), and a weak but significant relationship between Botswana–Namibia (r = 0.554) and South Africa–Namibia (r = 0.445) with regard to CMI, and suggest the possibility of transferring water from wetter to drier regions in the SADC study area.