Deserts: Geology and Resources

Deserts: Geology and Resources

Approximately one-third of the Earths land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Desertsstark, sometimes mysterious worldshave been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as Dune. These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry. Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved. Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world. There are almost as many definitions of deserts and classification systems as there are deserts in the world. Most classifications rely on some combination 5 of the number of days of rainfall, the total amount of annual rainfall, temperature, humidity, or other factors. In 1953, Peveril Meigs divided desert regions on Earth into three categories according to the amount of precipitation they received. In this now widely accepted system, extremely arid lands have at least 12 consecutive months without rainfall, arid lands have less than 250 millimeters of annual rainfall, and semiarid lands have a mean annual precipitation of between 250 and 500 millimeters. Arid and extremely arid land are deserts, and semiarid grasslands generally are referred to as steppes. ......Buy Now (To Read More)

Product details

Ebook Number: 47108
Author: Walker, A. S. (Alta Sharon)
Release Date: Oct 14, 2014
Format: eBook
Language: English