When did the sandstorm happen? Range? Why? Solution?

Sandstorm is a disastrous weather phenomenon in which wind and sand interact. Its formation is closely related to global greenhouse effect, El Nino phenomenon, forest decline, vegetation destruction, species extinction, climate anomaly and other factors. Among them, excessive exploitation of natural resources, excessive deforestation and excessive land reclamation caused by population expansion are the main reasons for frequent sandstorms.

As a kind of high-intensity sandstorm disaster, sandstorm can't happen in all windy places, but only in those areas with dry climate and sparse vegetation. In the northwest of China, the forest coverage rate is not high, and the poor northwest people want to make a fortune by digging licorice, holding seaweed and mining. These predatory acts of destruction further aggravated the sandstorm disaster in this area. Exposed land is easily rolled up by strong winds, forming sandstorms or even strong sandstorms.

Sandstorm is one of the most important meteorological and environmental disasters in China. Because of the dense wind and dust, its harm is extraordinary.

1, people and animals died, buildings collapsed, and agricultural production was reduced. Sandstorms are as harmful to people, animals and buildings as typhoons and tornadoes. In the past five years, the northwest of China has been hit by sandstorms for more than 20 times, resulting in economic losses of more than 654.38+0.2 billion yuan, and more than 200 people have died and disappeared.

2. Air pollution and topsoil loss. Dust storms contain at least 38 chemical elements, which greatly increase the concentration of atmospheric solid pollutants and cause long-term and potential harm to the atmospheric environment, soil and agricultural production in the origin, surrounding areas and downwind areas. Especially after the meager topsoil on which crops depend is scraped away, the barren land will seriously affect the yield of crops.

In addition to the general wind hazard, it also quickly eroded fertile farmland, blew away and killed seeds and seedlings, and knocked down fruits and flowers of cash crops. It also used sand to bury the lifelines of farmland, pasture and arid areas-canals and karez. After the leaves of the surviving crops are covered with dust, the photosynthesis and respiration are greatly weakened, which seriously affects the growth of crops. When there is a strong sandstorm, traffic accidents increase greatly, and planes, trains and cars are often forced to stop.

Strong sandstorms in China in recent 50 years

In the second half of the 20th century, China showed a rapid upward trend.

* * * happened five times in the fifties;

* * * happened eight times in the sixties;

In 1970s, * * * occurred 13 times;

In 1980s, * * * occurred 14 times;

It happened 23 times in the 1990s!

During the period of 1979, there were three sandstorms in Tarim Basin from April to June, of which only one occurred in Yuli County, and the average amount of dustfall per square kilometer in three days was 25,600 tons.

1983 Xinjiang Shihezi reclamation area was hit by a sandstorm, and 250,000 mu of crops were affected, resulting in direct economic losses of more than 3 million yuan.

10 in may, 1986, a gale of10 swept Hotan, and 200,000 mu of crops were affected, resulting in direct economic losses of more than 50 million yuan.

1In May, 1993, a strong sandstorm occurred in northwest China, resulting in the death and loss of120,000 head of livestock, 5.05 million mu of crops affected, 3 80 people died, and the direct economic loss was 540 million yuan.

1995, 15 In May, a serious sandstorm occurred in Gansu Province, which made the dust fall as high as 1243 10000 tons, equivalent to the output of the largest cement plant in the province15;

1April, 1998, northwest China 12 prefectures were hit by sandstorms, 46 1000 mu of crops were affected,1/0900 livestock died, 15600 people were affected, and the direct economic loss was 800 million yuan. ...

In March 2000, a sandstorm hit Beijing, 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.

The frequency of sandstorms in China is consistent with the speed of desertification expansion;

From 1950s to 1960s, desertified land expanded by 65,438 0,560 square kilometers every year.

From 1970s to 1980s, desertification land increased by 265.438 million square kilometers every year.

In the 1990s, desertification land expanded by 2460 square kilometers every year. Sandstorm is an alarm of land desertification, and the increase of sandstorm frequency and intensity is an alarm of ecological crisis!

Meteorologists reminded that people should pay attention to five points when traveling in dusty weather.

First of all, we should pay attention to walking and cycling, and take less long and narrow passages between tall buildings. Because the narrow passage will form a "narrow tube effect", the wind in the passage will increase, which will bring certain danger to pedestrians walking in it.

Second, be careful not to stay in billboards and old trees for a long time. Some billboards may collapse under the strong wind because they are not installed firmly; Moreover, some old trees are very likely to break in windy weather because they have died and their foundations are not firm, which will cause danger to pedestrians.

Third, we should pay attention to the safety of light vehicles. Because of its light weight, light vehicles may be lifted by strong winds when driving at high speed. So put something heavy on the light bus, or drive slowly.

Fourth, we should pay attention to riding bicycles as little as possible. Because in windy weather, downwind or headwind will not cause too much danger to riding, but once riding in crosswind, it is likely to be blown down by strong wind, causing physical injury.

Fifth, we should pay attention to carrying masks, scarves and other dust-proof products to avoid dust damage to the eyes and respiratory system.

The moving path and main influence areas of sandstorm in China;

Of the 32 sandstorms monitored in China last year, 18 were moved to China after the formation of sandstorms in southern Mongolia, accounting for 56% of the total number of times in the whole year. 1September, 1998, a sandstorm originated in the desert area of eastern Kazakhstan and passed through a vast area in northern China, and a large amount of dust was transported to North America through high altitude.

In spring, the dusty weather in northern China is accompanied by strong winds caused by cold air activities. There are three main paths for cold air to affect China:

East Road: It starts from eastern and central Mongolia in the south, affecting the northeast, eastern and central Inner Mongolia, Shanxi, Hebei and the south;

Middle Road: From the southeast of central and western Mongolia, it affects the central and western Inner Mongolia, the eastern part of northwest China, the central and southern parts of North China;

West Road: It moves from the west of Mongolia and the southeast of Kazakhstan, affecting the northwest, north and south areas including Xinjiang.

According to the observation results of meteorological stations in recent 50 years, sand blowing and sandstorm weather have occurred in most areas north of the Yangtze River in China, especially in the northwest. Dust-prone areas are mainly concentrated around Tarim Basin in Inner Mongolia, Dunhuang-Hexi Corridor-Ningxia Plain-Northern Shaanxi, Alashan Plateau, Hetao Plain and Ordos Plateau.