First, the dust source and path

Dust storms mainly occurred in the late spring and early summer season in winter and spring due to little rainfall in arid areas, unusually dry loose surface, anti-wind ability is very weak winds in the scratch, it will be a lot of dust into the air, the formation of dust storms weather.

From a global perspective, dust storms occur in the inland desert areas, the main source of sub-Saharan Africa, central and western North America and Australia is also the source of sandstorms one. 1933 as a result of a severe drought in 1937, in the central and western North America have been well-known on the sand bowl. Asian dust storm activity centers mainly in the Jordan desert, in Baghdad and between the north shore of the Gulf of Lower Mesopotamia, Abbas in southern Iran near the waterfront, crusgalli Road extension to the northern plains of Afghanistan. The former Soviet Union in Central Asia Kazakhstan, Uzbekistan and Turkmenistan are frequent dust storms (≥ 15 / year)-affected zone, but its center in the Caspian Sea and the Aral Sea between the sandy plains and along the Amu Darya.

Northwest China as a result of the unique geographical environment, but also areas of frequent storms, the main source of land Gurbantunggut desert, the Taklimakan Desert, Badain Jaran Desert, Tengger Desert, Ulan Buh Desert and Mu Us Desert, etc. .

Second, the concept of dust weather:

Dust into dust, Jansa, four types of dust storms and strong storms.

Dust: dust, sand floating in the air evenly, so that the level of visibility of less than 10 kilometers of weather phenomena;

Jansa: the wind blowing indeed harbor the ground, the air very turbid, the level of visibility in the 1-10 km within the weather phenomena;

Dust storms: strong winds will be blowing indeed harbor a large number of ground, air is turbid, the level of visibility less than 1 km of weather phenomena;

Strong dust storm: the wind will be blowing indeed harbor the ground, the air clear, turbid state, the level of visibility less than 500 meters of weather phenomena.

Third, against the way the major dust storms

⑴ strong wind: sand dust carry strong winds destroyed buildings and public facilities, resulting in human and animal death.

⑵ buried sand: a way to flow caused by wind farms, channels, cottage, railway, grasslands, such as burying a large number of quicksand, especially for the transport poses a serious threat.

⑶ soil erosion:The soil dust storm and each time zone will be affected to varying degrees against the wind erosion, wind erosion depth of up to 1 ~ 10 cm. It is estimated that China's dust storms per year generated by the fine-grained material and soil loss as high as 106 ~ 107 tons, most of them below 10 microns in diameter, of the source region of farmland and pasture land productivity cause serious damage.

⑷ air pollution: the source of the dust storms and the impact area, the atmosphere of respirable particulate matter (TSP) increased, exacerbated by air pollution. 1993 "5.5" an exceptionally strong storms as an example, the city of Gansu Province, Jinchang outdoor air concentration of TSP of 1016 mg/m3, indoor 80 mg/m3, more than 40 times the national standard. 2000 March-April, the Beijing area by the impact of dust storms, air pollution index of more than 4 have 10 days, at the same time affected many cities in eastern China. On March 24-30, including Nanjing, Hangzhou and other cities in 18 days over four pollution index.

black wind harm

There are hazar black wind word, first, second, sand wind.

Wind hazards also are two-fold: First, wind damage, and the other is land erosion scratch.

Said first wind damage. Wind damage to buildings, electricity poles blown over or uprooted trees, tearing up farmers and farm greenhouse plastic film and so on. In addition, the four north-west, in May is the fruits, vegetables, sugar beet, cotton and other cash crop emergence, growth or cotyledon Leaf and fruit trees bloom period, when the most intolerant adsurgens wind. Leaves range from dust, so that reduced photosynthesis, and affect the respiratory, lower crop yields; re Miller is dead flowers, it is much less mature result. For example, the 993-year May 5, so that the north-west-tipped stamens, fruits, 85,000 have been hitting net, 109400 shelterbelts and timber broken or uprooted. In addition, strong winds caused by water and electricity poles fell, the impact of industrial and agricultural production. May 5, 1993 blackouts caused by water, only a Jinchang City Jinchuan Company has caused economic losses of 83 million yuan.

The role of wind in the dry areas of loose soil will scrape a layer of topsoil, called the wind. For example, May 5, 1993 the average wind depth of 10 centimeters (up to 50 cm), that is, the average per mu to 60-70 cubic meters of fertile topsoil by wind away. In fact, strong winds not only blow away the soil clay and organic matter in a small, but also brought about the plot of sand in the soil, so that greatly reduced soil fertility. In addition wind sand folder to buildings and crops will be refining its stand surface layer, called the erosion, is also a disaster.

Sand is sand buried hazards. As mentioned above, a narrow tube, uplift, such as wind and terrain, as the wind speed, and wind is against wind erosion, and the concave depression in the lee of the terrain, such as small wind, the wind is against the main sand buried. For example, May 5, 1993 buried in the sand where the occurrence of sand buried the average thickness of 20 centimeters, the thickest Department has reached 1.2 meters.

In addition, more importantly, the loss of human life. For example, May 5, 1993 CPC death 85 people and injuring 264 people, 31 people missing. In addition, the loss of livestock have died and 120,000, 560 hectares of crops affected, sand buried drains the lifeblood of arid areas over 2,000 kilometers length, Lan-Xin Railway outage 31 hours. The total economic losses of more than 540 million yuan.

Fourth, sandstorm control and prevention measures of Sandstorm

1. To strengthen the protection of the environment, the protection of the environment referred to the height of the rule of law.

2. The restoration of vegetation, wind storms to strengthen the prevention of bio-defense system. Implemented in accordance with the law to protect and restore vegetation and prevent further expansion of land desertification, to minimize the source of the dus.

3. In accordance with local conditions in different regions to develop disaster prevention, disaster, disaster planning, and actively promote a variety of disaster reduction technology, and building a number of demonstration projects in order to point towards an area, and further improve the regional integrated defense system.