With it’s headwaters in the rainy and forested highlands of Angola, the Okavango River snakes its way southeast through the Caprivi Strip of Namibia and into Botswana. The Cuito and Cubango Rivers in the highlands of Angola are together what form the Okavango River and subsequently the Okavango Delta.
The heaviest rains in the Angolan highlands occur in April - October. Because of the seasonality of the precipitation, the delta swells to life when the upstream flood waters arrive (November - April) and shrinks when the dry season (May - October) approaches. The permanent wetland area is about 1,200 sq miles and the seasonal wetland is about 3,000 sq miles.
Using the Normalized Difference Vegetaion Index (NDVI), which is essentially "greenness", seasonal vegetation patterns can be monitored with remotely sensed imagery. In this web map, toggle between the "Wet Season" and "Dry Season" to see how NDVI represents differences degrees of vegetation "greenness" visually and statistically as represented on the graph. Pan and zoom around to see how vegetation in different areas like the highlands in Angola and the Delta to the Southeast in Botswana respond to seasonal differences.