The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the southwest, and by the North China Plain to the southeast. The Gobi is made up of several distinct ecological and geographic regions based on variations in climate and topography. This desert is the fifth largest in the world.

The Gobi is most notable in history as part of the great Mongol Empire, and as the location of several important cities along the Silk Road.

The Gobi is a rain shadow desert formed by the Himalaya range blocking rain-carrying clouds from reaching the Gobi.

Geography

The Gobi measures over 1,610 km (1,000 mi) from southwest to northeast and 800 km (497 mi) from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°-89° east). It occupies an arc of land 1,295,000 km2 (500,002 sq mi) in area, making it fifth largest in the world and Asia's largest. Much of the Gobi is not sandy but is covered with bare rock.

A relatively large area on the east side of the Greater Khingan range, between the upper waters of the Songhua (Sungari) and the upper waters of the Liao-ho, is also reckoned to belong to the Gobi by conventional usage. On the other hand, geographers and ecologists prefer to regard the western area of the Gobi region (as defined above), the basin of the Tarim in Xinjiang and the desert basin of Lop Nor and Hami (Kumul) as forming a separate and independent desert, called the Taklamakan Desert.

The Nemegt Basin in the northwestern part of the Gobi Desert (in Mongolia) is famous for its fossil treasures, including early mammals, dinosaur eggs, and even prehistoric stone implements, some 100,000 years old.

Climate

The Gobi is a cold desert, and it is not uncommon to see frost and occasionally snow on its dunes. Besides being quite far north, it is also located on a plateau roughly 910–1,520 meters (3,000–5,000 ft) above sea level, which further contributes to its low temperatures. An average of approximately 194 millimeters (7.6 in) of rain falls per year in the Gobi. Additional moisture reaches parts of the Gobi in winter as snow is blown by the wind from the Siberian Steppes. These winds cause the Gobi to reach extremes of temperature ranging from –40°C (-40°F) in winter to +50°C (122°F) in summer.

The climate of the Gobi is one of great extremes, combined with rapid changes of temperature, not only through the year but even within 24 hours (by as much as 35 °C or 61 °F).

Even in southern Mongolia the thermometer goes down as low as -32.8 °C (-27 °F), and in Alxa it rises as high as 37 °C (98.6 °F) in July.

Average winter minimals are a frigid -40 °C (-40 °F) while summertime temperatures are warm to hot, highs range up to 50 °C (122 °F). Most of the precipitation falls during the summer.

Although the southeast monsoons reach the southeast parts of the Gobi, the area throughout this region is generally characterized by extreme dryness, especially during the winter. Hence, the icy sandstorms and snowstorms of spring and early summer plus early January (winter).

Conservation, ecology, economy

The Gobi Desert is the source of many important fossil finds, including the first dinosaur eggs.

These deserts and the surrounding regions sustain many animals, including black-tailed gazelles, marbled polecats, bactrian camels, Mongolian wild ass and sandplovers, and are occasionally visited by snow leopards, brown bears, and wolves. The desert features a number of drought-adapted shrubs such as gray sparrow's saltwort, gray sagebrush, and low grasses such as needle grass and bridlegrass.

The area is vulnerable to trampling by livestock and off-road vehicles (human impacts are greater in the eastern Gobi Desert, where rainfall is heavier and may sustain livestock). In Mongolia, grasslands have been degraded by goats, raised by nomadic herders as source of cashmere wool. Economic trends of livestock privatization and the collapse of the urban economy have caused people to return to rural lifestyles, a movement contrary to urbanization.

Large copper and gold deposits located at Oyuu Tolgoi, about 80 kilometers from the Chinese border into Mongolia, are being investigated for mining operations.

Desertification

Currently, the Gobi desert is expanding at an alarming rate, in a process known as desertification. The expansion is particularly rapid on the southern edge into China, which has seen 3,600 km2 (1,390 sq mi) of grassland overtaken every year by the Gobi Desert. Dust storms, which used to occur regularly in China, have seen a dramatic increase in occurrence in the past 20 years, mainly due to desertification, and causing further damage to China's agriculture economy.

The expansion of the Gobi is attributed mostly to human activities, notably deforestation, overgrazing, and depletion of water resources. China has made various plans to try to slow the expansion of the desert, which have met with some small degree of success, but usually have no major impact. The most recent plan involves the planting of the Green Wall of China, a huge ring of newly-planted forests that the Chinese government hopes will act as a buffer against further expansion.

credited to wikipedia