Research 03_Oasis

 

 https://www.youtube.com/watch?v=nuJ6QTZdvxM

 Oasis are places where aquifers are connected to the surface. The source of the water in the aquifer however can be hundreds of miles away in areas that do get significant rainfall. 

There are two types of oases: natural and human made.

Natural oases form when springs, created when underground aquifers allow fresh water to pool or flow on the ground surface of deserts, creating a fertile region.

A human made oasis occurs when humans create fertile region in a dry or arid region, such as a desert. The supply of water in human made oases is from underground water supplied by human made wells or water bores. Because wind-blown desert sands can damage or destroy wells, sturdy trees (such as palm trees) are planted around the periphery of the oases. 

 

The surface water is basically at the intersection of the water table and the ground surface. That is, the ground water extends underneath the ground in all directions from the oasis. That is why the water in the oasis doesn't leak out - because it's surrounded by ground saturated with water

 

https://earthscience.stackexchange.com/questions/18634/how-do-oases-form-in-the-middle-of-the-desert 

http://www.laboasis.org/oasis-traditional-water-systems/

 

QANAT