The Kalahari desert (named after the tribal word Khalagari ~ waterless place) isn't a true desert, rather a semi-desert of reddish sand that covers an area slightly more than a third of a million square miles covering much of Botswana and extending into Namibia and South Africa and as far as Zimbabwe located between the Orange and Zambezi rivers. The reason it's not classified as a proper desert is that it receives rainfall (between five inches in the south-west to twenty inches a year in the north-east of the desert) and is home to a variety of animals and plants not found in a true desert.
It is also home to the San (bushmen, below) people who live predominately in the north of the Kalahari. Temperatures range from 20-40 degrees in the summer months to freezing during the winter period. The area now known as the Kalahari Desert was formed over sixty million years ago when the area was a shallow water basin.
Exactly what happened is unknown, however the commonly accepted theory is that before that time the Okavango, Kwando and Zambezi rivers followed into a single channel that crossed through today's Kalahari desert area towards the sea.
A few million years ago seismic shifts forced much of the land of Botswana upwards blocking the flow of the channel and creating a superlake that dried out over thousands of years leaving behind vast white salt deposits that form part of the desert as we know it today. Today the Okavango river remains as the Kalahari's only permanent river, however as in its history, it no longer flows into the sea, rather empties into a swamp area called the Okavango Delta. This region produces the Hoodia, a plant that is world renowned for suppressing hunger, and, after eating it, the San people claim to go a further 24 hours without feeling any hunger, although there is no scientific evidence for any claims about Hoodia. There used to be over a million San living in the Kalahari desert, however that number is now down to about 2000 following years of persecution by neighbouring tribes.
The traditional lifestyle of gathering
and hunting is expected to be further damaged by increasing
climate change, with an expected 40% drop in rainfall over the
next few decades.
The Kalahari desert is also home to around
55,000 Khoikhoi who are related to the San and who live mainly in Namibia and South Africa
living a lifestyle both as hunters and farmers whilst a
dwindling number continue a nomadic existence.
The
Kalahari desert is also home to the Kgalagadi Transfrontier
National Park created by the amalgamation of the Kalahari
Gemsbok National Park in South Africa and the Gemsbok National
Park in Botswana.
The national park is now one of the world's
largest conservation areas and features several species of
antelope, lions, brown hyenas, meerkats and a number of
different birds and reptiles. The above
slideshow shows pictures of the Kalahari Desert whilst the
videos explore its wildlife and hunter gatherers.
The traditional lifestyle of gathering
and hunting is expected to be further damaged by increasing
climate change, with an expected 40% drop in rainfall over the
next few decades.
The
Kalahari desert is also home to the Kgalagadi Transfrontier
National Park created by the amalgamation of the Kalahari
Gemsbok National Park in South Africa and the Gemsbok National
Park in Botswana. 
