Desert Zones

Desert Zones


geographic areas in which deserts are the predominant natural landscape. Desert zones occur widely in the temperate belt of the northern hemisphere and in the subtropical and tropical belts of both the northern and southern hemispheres. Their common characteristic is aridity. The total annual precipitation is less than 200 mm and in extremely arid regions, less than 50 mm. The moisture coefficient, which reflects the ratio of precipitation to rate of evaporation, varies from 0 to 0.15.

The topography combines uplands, low isolated hills, and inselbergs with structural stratified plains, ancient river valleys, and enclosed lake basins. Relief formation by erosion is weak, and colian landforms are common. Most desert terrain lacks drainage, although it is sometimes intersected by through-flowing rivers, such as the Syr Darya, Amu Darya, Nile, and Huang Ho. There are many dry lakes and lakes whose shape and size change frequently (Lop Nor, Chad, Eyre). Intermittent streams are characteristic, and the groundwater is often saline. The soils are poorly developed, with soluble salts predominating over organic matter in the soil solution. Salt crusts are common.

The vegetation is sparse, usually covering less than half of the soil surface. Under extremely arid conditions it is almost nonexistent. Xerophilic and halophilic communities of Haloxylon, ephemerals, and Artemisia are widely found in Asian deserts. Cactus and creosote bush associations prevail in North American deserts. Although the animal world is fairly diverse, the forms of adaptation to desert conditions are similar. Rodents and reptiles predominate in all deserts. Pasture livestock raising is well developed in desert zones, but agriculture is possible only with irrigation.


Fedorovich, B. A. Lik pustyni, 3rd ed. Moscow, 1954.
Petrov, M. P. Pustyni zemnogo shara. Leningrad, 1973.
Meigs, P. Geography of Coastal Deserts. Paris, 1966.
Cooke, R., and A. Warren. Geomorphology in Deserts. Berkeley-Los Angeles, 1973.
Monod, T. Les déserts. Paris, 1973.


References in periodicals archive ?
May 14, 2014 /PRNewswire/ -- The North Carolina Parent Teacher Association (NCPTA) applauds and supports the inclusion of Parent Teacher Associations (PTAs) in both the findings and recommendations that were adopted by the North Carolina General Assembly's House Legislative Research Commission (LRC) Committee on Food Desert Zones and approved by the main LRC on May 13.
NCPTA Executive Director Debra Horton and President-Elect Kelly Langston presented to the NCGA House LRC Committee on Food Desert Zones in March 2014.
Yearning to see its changes on desert zones, plains, hills and vales.
The latter accounts for nearly 32% of desert zones in the world, which prevents several African countries from achieving the Millennium Development goals.
At dusk we leave behind these arid, desert zones and awake the following morning on the coast of South America.
Start seeds now through September in all but desert zones 11-13.
Rather, desertification is the creation of desert-like conditions in the arid and semi-arid regions which lie near the world's five main desert zones.
Globally, only one percent of all desert zones would be sufficient to supply the world's electricity demand with this type of power plant.
Most of the conifers listed below grow well in Sunset Western Garden Book climate zones 1-7; with the exception of junipers, they are not recommended for desert zones 10-13.
adpressus praecox or - in all but desert zones 12 and 13 - rock cotoneaster (C.