Charene Cherry age.,9 of Tulsa, Okl ; for his questron:
What makes a desert?
We think of a desert as a hot, dry, sandy wasteland. Actually, there are very few deserts of this sort. There are cold deserts and medium warm deserts covered with shaggy vegetation. You may say a desert is any land area which is unable to grow enough plants to support human life. This would include about 20% of all the land in the world.
Desert areas have low and undependable rainfall. But no desert area is entirely without rainfall. Evaporation goes on ail over the face of the earth. Everywhere the moisture in the ground and from the sea is being drawn up into the air. In a desert the evaporation is greater than the yearly rainfall, Not enough rain water stays in the ground to feed a healthy crop of plants.
Low rainfall may be caused by a high range of mountains. They often steal the moisture from the clouds before it reaches the desert area. Some mesa and plateau areas are unable to hold onto the scanty rainfall they do get. The gushing water runs off in deep gullies leaving the soil around parched and dry. Desert soil is not necessarily poor soil. In many places it has been irrigated and has brought forth wonderful, plants and crops,