Animation of NDVI over the course of a year for the Sahel Region
| This animation shows the level of "greenness" across North Africa for the period beginning February 1995 and ending January 1996. The "greenness" of a certain part of the Earth is directly related to how much vegetation exists there at a certain time. The large, tan-colored expanse of land of Northern Africa is the Sahara Desert, the largest desert in the world. To the south (bottom of the image), forested areas dominate the area. Between these two regions exists an east-west swath of transitional territory called the "Sahel" region. The Sahel is essentially an oscillating, savanna boundary that becomes greener in the summer months of June, July and August, and loses its greenness in the winter months of December and January. The effect of this "greening and fading" manifests itself as an advancing-and-receding line of active vegetation in a north-south fashion as the seasons change over the course of a year. This seasonal change in vegetation cover directly affects the migration patterns of many species of animals that live in the Sahel region, as well as the agricultural patterns of the people who live in these areas. |
Credit: Dylan Prentiss, Department of Geography, UCSB
For more info: http://www.geog.ucsb.edu/~dylan/mtpe/avhrr/ndvi.html