, Johan Malherbe, Harold Weepener, Phelix Majiwa, and Robert Swanepoel
Figure 4. Comparison of monthly rainfall amounts, normalized difference vegetation indices (NDVIs), and soil saturation indices (SSIs) for August 2008–May 2012 for the following 4 areas of South Africa where Rift Valley fever epidemics occurred: A) Southern region of KwaZulu-Natal Province (outbreaks in February–March 2009); B) Orange River region in Northern Cape Province (outbreaks in October–November 2009); C) Bultfontein area of Free State Province (outbreaks in January–February 2010); D) Graaff-Reinet area of Eastern Cape Province (outbreaks in January–February 2011). Rainfall and NDVI anomalies were computed as percentage of the maximum of the long-term means (LTMs); SSI anomalies were computed as percentage of the LTM. Arrows indicate time of first outbreak in the region.