Where does the sandstorm mainly start?

Sandstorm weather mostly occurs in inland desert areas, and the main source is the Sahara desert. The midwest of North America and Australia are also one of the sources of sandstorms. 1933- 1937 Due to severe drought, a famous bowl-shaped sandstorm occurred in the midwest of North America. Asian sandstorm activity centers are mainly located in the Jordanian desert, Lower Mesopotamia between Baghdad and the northern coast of the Gulf, the southern Iranian coast near Abbas and the northern Afghan plain. Kazakhstan, Uzbekistan and Turkmenistan in Central Asia of the former Soviet Union are often affected by sandstorms, but their centers are all on the sandy plain between Caspian Sea, Aral Sea and Amu Darya River. Due to the unique geographical environment, the northwest of China is also a region with frequent sandstorms. The main source areas are Gurbantunggut Desert, Taklimakan Desert, Badain Jaran Desert, Tengger Desert, Wulanbuhe Desert and Mu Us Desert. From 1999 to the spring of 2002, there were 55 times 12 sandstorms in China, of which 3 times/kloc-0 originated in the Gobi area in central and southern Mongolia. In other words, about 60% of the sandstorms that ravage China every year come from abroad. This is the research result released by Li Huang, deputy director of China Meteorological Bureau, to the media on July 2nd. He said that in the spring of 2002, there were 12 sandstorms in northern China. It has three characteristics: concentrated occurrence period, strong occurrence intensity and wide influence range. The sources of dust weather affecting China can be divided into two types: overseas and domestic. The analysis shows that two-thirds of the dusty weather originated in southern Mongolia and was supplemented by dusty materials when passing through northern China. The sand source in China is only about one third. The dusty weather in Central Asia (Kazakhstan) is unlikely to affect the eastern part of Northwest China or even North China. The Taklimakan Desert in southern Xinjiang is a high incidence area of sandstorm weather in China, but it generally does not affect the eastern part of northwest China and North China. The dust weather path in China can be divided into northwest path, west path and north path: northwest path 1. Dust weather generally originates from the central and western plateau of Mongolia or Alashan Plateau in western Inner Mongolia, and mainly affects northwest and north China. Northwest Route 2. Dust weather originated in southern Mongolia or central and western Inner Mongolia, mainly affecting the eastern part of northwest China, northern North China and most of northeast China; To the west, dusty weather originated in Gobi area in southwest or south Mongolia and desert area in western Inner Mongolia, mainly affecting northwest and north China. In the northerly route, dusty weather generally originates in the vast area south of Ulaanbaatar, Mongolia, and mainly affects the eastern part of northwest China, most of north China and southeast China. There are four sandstorm-prone areas in the world, namely North America, Australia, Central Asia and the Middle East.

The deserts in North America are mainly distributed in the western United States and northern Mexico. In the desert arid area bordering the desert, sandstorms occur from time to time, and even the famous black storm broke out in the Great Plains. The main causes of sandstorms in North America are improper land use and persistent drought. In 1930s, a big sandstorm happened in the Great Plains of the western United States, which was called the Black Storm. In the worst sandstorm in American history, the Great Plains lost 300 million tons of fertile soil. After the disaster, millions of hectares of farmland were abandoned, hundreds of thousands of people were displaced, and many towns became barren and empty cities. Many people were forced to move to California, which triggered the largest immigration wave in American history. Australia is an arid country, and 74.8% of its land area belongs to arid and semi-arid areas. Sandstorms occur most frequently in the coastal areas of central and western Australia, with an average of five times a year. Due to the dry climate, farming and grazing in many places, the soil surface lacks vegetation coverage, which leads to the gradual desertification of the land. Once the wind blows, sandstorms will happen. The desert area in Central Asia is also expanding. The five Central Asian countries are serious desertification areas with a total area of nearly 4 million square kilometers. Due to the rapid increase of population, over-irrigation water, deforestation, overgrazing, grassland degradation and desertification are very serious. The area of saline soil in Central Asia is very vast, reaching 6.5438+0.5 million square kilometers, resulting in the mixed occurrence of sandstorms and salt dust storms. Sandstorms in the Middle East are mainly on the southern edge of the Sahara Desert in Africa. From the early 1970s to the mid-1980s, due to successive years of drought and overgrazing and reclamation, grasslands were degraded, fields were deserted, desertified land spread, sandstorms intensified, and people's living environment deteriorated sharply. Frequent sandstorms have also affected other regions, some of which have been brought across the Atlantic to the Amazon region of South America, while others have been blown to Europe.

Sandstorm weather in China

According to statistics, there have been eight sandstorms in China, and the scope is getting wider and wider, resulting in more and more serious losses. Several major gale and sandstorm weather events in China since 1990s are described as follows:1993: From April to early May, gale weather appeared in the north for many times. From April 19 to May 8, Gansu, Ningxia and Inner Mongolia were successively hit by strong winds and sandstorms. On May 5-6, eastern Xinjiang, Hexi in Gansu, most of Ningxia and western Inner Mongolia were hit by severe sandstorms, causing serious losses. 1994: From April 6th, strong winds blew in the western part of Mongolia and Inner Mongolia, and the dust in the Gobi desert in the north was lifted by the wind and floated over the Hexi Corridor, and the loess lasted for several days. 1 995:165438+1On 7 October, more than 40 counties (cities) in Shandong were hit by heavy rain, with 35 people killed, 12 1 missing, 320 injured and direct economic losses/kloc-0. 1996: On May 29th and 30th, 1965, the worst sandstorm swept the west of Hexi Corridor. The black wind suddenly broke out, the world was closed, the dust filled, the trees collapsed, and people had difficulty breathing. The direct economic loss in Jiuquan area, which suffered the most, reached more than 200 million yuan. 1998: On April 5, the central and western Inner Mongolia, southwestern Ningxia and Hexi Corridor in Gansu were hit by strong sandstorms, which affected a wide range, including Beijing, Jinan, Nanjing and Hangzhou. On April 19, Tutanto Basin in northern and eastern Xinjiang was hit by a strong wind with an instantaneous wind force of 12, and some areas were accompanied by dust. The devastating typhoon caused a lot of property losses, with 6 people dead, 44 missing and 256 injured. 19 In the early morning of May 1, northern Xinjiang was suddenly hit by strong winds. The wind power in the tuyere areas such as Alashankou and Tacheng reaches 9 to 10, and the instantaneous wind speed reaches 32 meters per second. The winds in other areas generally reach 6 to 7. Strong winds blew down trees and cut off power lines in some areas. 1999: From April 3rd to 4th, there were continuous strong winds and sandstorms in Hohhot for two consecutive days. Sandstorms range from the west of Inner Mongolia Autonomous Region to the south of Tongliao City in the east, with instantaneous wind speed 16 meters per second. Maximum wind force in Dalat Banner of Yikezhao League 10. 2000: On March 22-23, there was a large-scale dusty weather in Inner Mongolia Autonomous Region, and some dust was carried over Beijing by strong winds, which aggravated the degree of sand blowing. On March 27th, the sandstorm hit Beijing again, and the instantaneous wind force in some areas reached 8-9. Seven workers who were working on the roof of a two-story building in Anxiangli Community were blown down by strong winds, and two of them died on the spot. Some billboards were blown down by strong winds, causing pedestrian injuries and vehicle damage. 2002: From March 18 to March/2 1 2002, the sandstorm weather process with the largest scope, strongest intensity, the most serious impact and the longest duration has hit the land of1400,000 square kilometers in northern China, affecting the population of1300,000.