Two approaches are used i.e. NDVI (plant activity) and PASG (accumulated seasonal greenness). It is expected that above normal rains of the current season should result in above normal conditions for plant activity. In general, all three images indicate at least similar to above normal plant activity or greenness, compared to last year and the long term. Interestingly, more plant activity was recorded in the east, which was ascribable to the nature of plants being more summer rainfall oriented. The western side of the province obviously had less plant activity or greenness due to the remarkably less acreage of actively growing or developing crops this time of the year. The green spots could probably be matched with eg. vineyards, orchards, potatoes (Sandveld), summer crops under irrigation, ect.
The current drought experienced in the mid Central Karoo is clearly pointed out in all three images. The fact remains that the drought is certainly abnormal, thus emphasising the appropriate aid to those producers in the affected area.
Other below normal situations (red) can also be seen, although being much smaller areas and isolated. These will be verified and if necessary carefully monitored and during the following months.
20 – 31 August 2009
NDVI values are still increasing over the winter rainfall area, especially the important grain producing areas.
21-31 August compared compared to 21-31 August 2008
NDVI values are lower than a year ago over the eastern parts of the province, but higher over the western and southwestern areas including the Swartland and Ruens.
21 – 28 August 2008 compared with the long-term mean
Vegetation activity is somewhat higher than the long-term average over most of the province, except for some areas in the southeast.
Percentage of Average Seasonal Greenness (PASG): April - August 2009 compared with the long-term mean
Percentage of Average Seasonal Greenness (PASG) for this period is above-normal over the northern parts of the province, but below-normal over the southeastern parts and isolated areas in the west where burn scars can be seen in below-average cumulative NDVI values.