Originally posted by motoged
I always considered the fact that there was a river and palms in the middle of rocky desert enough to think the town was an oasis.
"From Wikipedia, the free encyclopedia
For the English band, see Oasis (band). For other uses, see Oasis (disambiguation).
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Oasis in the Libyan part of the Sahara
In geography, an oasis (plural: oases) or cienega (Southwestern United States) is an isolated area of vegetation in a desert, typically surrounding a
spring or similar water source. Oases also provide habitat for animals and even humans if the area is big enough. The location of oases has been of
critical importance for trade and transportation routes in desert areas; caravans must travel via oases so that supplies of water and food can be
replenished. Thus, political or military control of an oasis has in many cases meant control of trade on a particular route. For example, the oases of
Awjila, Ghadames, and Kufra, situated in modern-day Libya, have at various times been vital to both North-South and East-West trade in the Sahara.
An oasis in the Negev Desert
Oases are formed from underground rivers or aquifers such as an artesian aquifer, where water can reach the surface naturally by pressure or by
man-made wells. Occasional brief thunderstorms provide subterranean water to sustain natural oases, such as the Tuat. Substrata of impermeable rock
and stone can trap water and retain it in pockets, or on long faulting subsurface ridges or volcanic dikes water can collect and percolate to the
surface. Any incidence of water is then used by migrating birds, which also pass seeds with their droppings which will grow at the water's edge
forming an oasis." |