Page 12 - Discover Botswana 23rd Edition 2023
P. 12

   Itis October and the land is dry. Crying out for moisture, parched fingers that once carried leaves reach to the sky. Spritely dust devils dance around them, mocking their thirst with lively twists and twirls. There is no other movement on the plains, no grass to sway in the breeze, no more leaves to fall from the trees. Above the baking surface a soaring vulture dips a wing, beginning a slow descent. It hasn’t had to travel far to spot a striped carcass, a rib cage already gleaming white in the glare. In this heat, meat doesn’t last very long; no matter though for there is no shortage of supply. Not all will make it through the first brutal months
of summer before the rains arrive.
This picture is a very common one across Botswana
during the early summer months. The vast majority of the country is arid to semi-arid desert, with the exception of a large salt flat and a large swamp. We know this swamp as the world’s largest inland delta and UNESCO World Heritage site number 1000, the Okavango Delta. The scene described above is one that plays out every year in the Okavango.
What is truly remarkable is the transformation from harsh desert to bountiful wetland. So, how does it work, what is the current state of the Okavango and what does the future look like?
Before understanding the Okavango itself, it is important to note the geological history of the area. Very briefly, millennia ago four major rivers drained the mountainous areas of central Africa and carried sediments southwards into southern Africa. This created the greater Kalahari sand basin, a vast expanse of land that covers most of southern Africa. At some point in their history these rivers were influenced by seismic activity to form a colossal lake, before 2 of the rivers were captured by what is now the lower Zambezi system. The remaining 2 rivers seeped into the sand basin without enough energy to keep the lake alive. Their descent from the Angolan highlands was also hampered by a series of fault lines that effectively hem in a roughly 15 000 square km expanse of flat, sandy terrain. Upon this, the rivers deposited their water. Just as a spilled bucket on the beach creates a tree-like pattern of waterways in the sand, so 11 cubic kms of spilled water form the Okavango Delta.
Facing pages An inquisitive Bush Baby (Lesser Galago) perches for a moment in soft green foliage. The forest echoes with their myriad calls as they prepare for a busy night of foraging.

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