Home: TRD: Resource utilisation: AGRI-OUTLOOK: NDVI FOR July 2010
This sections deals with the photosynthetic activity of plants (NDVI) within the Western Cape which is illustrated by means of four different NDVI maps. The first map shows plant activity within the current season (figure 1). The second map compares plant activity of the current season to the previous season (figure 2), while the third map compares plant activity of the current season to the historical long-term average (figure 3). In addition, figure 4 (Percentage average seasonal greenness or PASG) is a compilation of accumulated plant activity during the latest three months.
The colours applied in each map are as follows. Above normal rains result in above normal conditions for plant activity and is illustrated by different shades of green. Conversely, below normal conditions relate to poor plant activity which is identified by yellow to orange to red areas. Interestingly, the areas subjected to veld-fires are obviously illustrated by orange to red patches.
NDVI for 21 to 30 July 2010
Blue and green patches in the south coast, Overberg and West Coast indicate high vegetation activity, showing that agricultural growing conditions were good / improving. In the Central Karoo plant activity remained poor in the area between Laingsburg and Beaufort West, and also the area just south and west of Murraysburg. The latter could imply a possible return to drought conditions.
21 – 31 July 2010 compared with 21 – 30 July 2009
We notice that the NDVI are lower than last year over most of the province, except for isolated cases in the western side of the province.
21 – 31 July 2010 compared with July long-term mean
Compared to the long-term average, vegetation activity in the West Coast has increased this year over the winter months, revealing above normal growing conditions for grain crops. George, Knysna, Riversdale and Swellendam areas still show persistent below normal plant activity. The situation in the Little Karoo and Central Karoo also remain the same.
Percentage of Average Seasonal Greenness for November 2009 to July 2010
The PASG for April to June this period remained normal to above normal over most of the province, especially regarding the West Coast. Eden, the Overberg and the Central Karoo indicate isolated patches of below normal conditions (orange to red areas). The burnt scars caused by the fires earlier this year can still be identified by the red patches (eg. Augulas). The drought between Mossel Bay and Riversdale is still clearly evident.
