What is the largest desert in southern africa?

Answer the collision of tectonic plates;

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

No map. ie where is the map as this question cannot he answered without a map so the question as is is irrelevant and i am disappointed as i am a geologist.

The development in there economic is that is that they are a state of business. not to mention there government!