What Is an Oasis?
Many deserts are almost totally without water. Few plants can live in the dry, moving sands of these deserts. An oasis in the desert is a place where a natural spring, or irrigation from wells, gives plants the water they need to grow.
Oases are like green islands in the middle of the desert. Oases also provide habitat for animals and even humans if the area is big enough. People living in oases can grow many crops, including dates, grapes, oranges, wheat, barley, and corn.
Some of these little desert spots are separated by many miles of desert from one another. People traveling through the desert stop at oasis to replenish their water and food supplies.
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.
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.