DEFINITION OF RAINSHADOW DESERTS

A third type of desert is found on the leeward (or back) side

of some large mountain ranges, such as the sub-Andean

Patagonian Gran Chaco and Pampas of Argentina, Paraguay,

and Bolivia. A similar effect is partly responsible for the formation

of the Mojave and Sonoran deserts of the United

States. These deserts form because as moist air masses move

toward the mountain ranges they must rise to move over the

ranges. As the air rises it cools, and cold air can hold less

moisture than warm air. The clouds thus drop much of their

moisture on the windward side of the mountains, explaining

why places like the western Cascades and western Sierras of

the United States are extremely wet, as are the western Andes

in Peru. However the eastern lee sides (or back sides) of these

mountains are extremely dry. The reason for this is that as

the air rose over the fronts or windward sides of the mountains,

it dropped its moisture as it rose. As the same air

descends on the lee side of the mountains it gets warmer and

is able to hold more moisture than it has left in the clouds.

The result it that the air is dry and it rarely rains. This

explains why places like the eastern sub-Andean region of

South America and the Sonoran and Mojave deserts of the

western United States are extremely dry.

Rainshadow deserts tend to be mountainous because of

the way they form, and they are associated with a number of

mass wasting hazards such as landslides, debris flows, and

avalanches. Occasional rainstorms that make it over the

blocking mountain ranges can drop moisture in the highlands,

leading to flash floods coming out of mountain

canyons into the plains or intermountain basins on the lee

side of the mountains.

Title Post:
Rating: 100% based on 99998 ratings. 99 user reviews.
Author:

Terimakasih sudah berkunjung di blog SELAPUTS, Jika ada kritik dan saran silahkan tinggalkan komentar