Provincial Seasonal Rainfall Map
Provincial seasonal rainfall graphs provide useful information about a region's rainfall but do not give a clear indication of where the major rain events actually occurred. For that, we will look at a provincial seasonal rainfall map from SAWS. Note that areas with above-average rainfall are likely to have wet soil conditions (high soil moisture values). These conditions reduce the ability of the ground to absorb additional rainfall.
![Provincial seasonal rainfall map showing the percentage of normal for the 2009/2010 hydrological season in South Africa](media/graphics/prov_seasonal_rainfall_map.jpg)
Forecasters should start being concerned about rainfall-induced flooding when rainfall reaches between 100 and 150%. According to these data, which areas are at risk of flooding? Select all that apply, then click Done.
The correct answers are B and C.
The regional map helps narrow our focus. All of Gauteng is at risk for flooding since it received between 100% and 150% of its average rainfall. Significant portions of Mpumalanga are at risk as well, with some areas receiving 100% to 150%. Some areas within Mpumalanga received below average rainfall, from 50% to 75%.