dust (sand duststorm) is the sandstorms (sandstorm) and dust storms (duststorm) both, the general term, refers to the ground a lot of strong winds blowing dust and material involved in the air, the air especially turbidity, horizontal visibility less than one kilometer severe sandstorm weather phenomena. Sandstorms which means a large amount of wind blown sand formed by the surface layer of sediment-laden storm; dust storm is the wind blew a lot of fine dust and other substances involved in the formation of high-altitude storm.
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recent years, China's concept of dust weather windy weather, dust, dust regulations and standards of the concept of dust weather weather weather alerts issued during the standard classification of dust sandstorm sandstorm causes and physical mechanism Weather causes of the physical mechanism of the formation of dust storms mainly against the dangers of dark and stormy way the causes of dust storms originated the culprit wind erosion dust storms dust hazards of environmental degradation production and living life and property loss affected traffic safety hazards to human health impact of dust storms in the level ecosystems, the role of dust in the dust storm disaster management and emergency prevention measures related to the appearance of dust storms can not see the legal world's largest source of dust monitoring system and path of dust storms occurred in the inland desert areas, the main source of the Sahara, central and western North America and Australia is one of the source of sandstorms. 1933 to 1937 because of severe drought in central and western North America to produce the famous dust bowl. Asian dust storm activity centers mainly in the Jordan desert between Baghdad and the northern Gulf Coast next Mesopotamia, Abbas in southern Iran near the beach, barnyard Road branch to the plains of northern Afghanistan. Former Soviet Union, Central Asia, Kazakhstan, Uzbekistan and Turkmenistan are the frequent dust storms (≥ 15 / year)-affected zone, but its center in the sandy plains between the Caspian and the Aral Sea and Amu Darya area. Northwest China due to the unique geographical environment, the area is frequent dust storms, the main sources are Gurbantunggut desert, the Taklimakan Desert, Badan Jaran Desert, Tengger Desert, Ulan Buh Desert and Mu Us Desert, etc. . From 1999 to the spring of 2002, China's total territory 55 times (nine times in 1999, 2000, 14, 18, 2001, 2002, 12) dust weather, of which 31 originated in the Gobi Desert in south-central Mongolia region, in other words, our raging dust each year, about 60% from outside. This is the July 2, Li Huang, deputy director of China Meteorological Administration released the results to the media. He said the spring of 2002, appeared in northern China were 12 dust weather process. With the emergence of slot concentration, the occurrence of intensity, affect a wide range of features such as 3. Affect the source of dust weather in China can be divided into two kinds of foreign and domestic. Analysis shows that: two thirds of the dust weather originated in southern Mongolia, northern China, when to get in through the dust substances added to strengthen; only about one third of the territory of sand. In Central Asia (Kazakhstan) and dust weather, can not affect the eastern part of Northwest China and North China region. Southern Xinjiang, the Taklimakan Desert is a high incidence of dust weather in our country, but generally will not affect the eastern part of northwest and north China. Dust weather in China can be divided into a northwestward path, the path west and north path: the path northwest of road, sand and dust storms generally originated in the Midwest or the Inner Mongolian Plateau in western Alashan Plateau, the main impact of China's northwest, north; 2-way path to the northwest, sand and dust storms originated in the central and western Inner Mongolia or southern, mainly affecting the eastern part of Northwest, North China, Northeast most; west path, sand and dust storms originated in the southwest or south of the Mongolian Gobi region, the western desert area of Inner Mongolia, the major impact on China's northwest and north; northerly path, sand and dust storms generally originated in the south of Ulaanbaatar, Mongolia, a vast area, affecting mostly eastern part of northwest, north and northeast most of the south. There are four major storms world-prone areas, which are: North America, Australia, Central Asia and the Middle East. North America, mainly in the desert western United States and northern Mexico. In arid and desert areas bordering the desert, dust storms have occurred, even in the Great Plains, broke out on the history of the famous black storm. North America, mainly due to dust storms improper land use, sustained drought. 1930s occurred in the western U.S. Great Plains, a large dust storms, known as the black storm in U.S. history in this most severe dust storms in the Great Plains lost 3 million tons of fertile soil. After the catastrophe, millions of hectares of abandoned farmland, hundreds of thousands displaced, many cities and towns has become a deserted ghost town. Many are forced to migrate to California, led to the largest waves of immigration in U.S. history. Australia is an arid country, 74.8% of the land area of arid and semi-arid regions. Australia's central and western coastal areas are most frequent dust storms, there are on average five times as much. As many parts of the dry climate, with farming and grazing, lack of vegetation cover the soil surface, resulting in the gradual desertification of land, once the blowing wind, dust storms occur. Central Asia's desert areas are expanding, and the five Central Asian countries is more serious desertification areas, with a total area of nearly 400 million square kilometers. The rapid increase in population, man-made excessive irrigation water, forest deforestation, overgrazing, pasture degradation, desertification is very serious. Central Asia is a vast area of saline soil, to 15 million square kilometers, so the resulting mixture of dust and salt dust storms occur. Mainly in the Middle East sandstorm southern edge of the Sahara region of Africa, from the early 1970s, the mid-1980s, due to successive years of drought and excessive grazing and cultivation, resulting in degraded pasture, barren land, the spread of land desertification, dust storms increase, people's lives environment deteriorated sharply. Frequent dust storms also bring disaster to the other regions, and some dust with the wind over the Atlantic to the Amazon region of South America, as well as the dust was blown to Europe. Dust weather in China in recent years by the statistics of wind, dust storm occurred in our country had eight times, more and more wide spread range, causing increasingly heavy losses. Now emerged in China since the 1990s, several major wind and dust storms of the situation described below: 1993: April to early May, the North many times windy weather. April 19 to May 8, Gansu, Ningxia, Inner Mongolia have been strong winds and sandstorms. One 5 to 6 May, a large dust storm hit eastern Xinjiang, Gansu Hexi, most Ningxia, western Inner Mongolia region, causing serious damage. 1994: April 6, starting from China's Inner Mongolia and west winds blowing, the wind north of the Gobi desert dust into the sky, floating to the Hexi Corridor over the last few days filled loess. 1995: November 7, Shandong, more than 40 counties (cities) suffered storm attacks, 35 people were killed, 121 missing and 320 injured, the direct economic loss of 10 million yuan. 1996: May 29 to 30, since 1965 strong sandstorm hit the worst western Hexi Corridor swept, sudden, dark and stormy, the world closed, dust filled the air, trees crashing down, people breathing difficulties, damage to the serious direct economic losses in Jiuquan $ 250 yuan. 1998: April 5, central and western Inner Mongolia, Ningxia, southwest, along the Hexi Corridor in Gansu suffered a strong sandstorm hit, affecting a wide range,[url=http://www.bootsugg.us/][b]title=UGG Clearance[/b][/url], spread to Beijing, Jinan, Nanjing, Hangzhou and other places. April 19, the northern and eastern Xinjiang, Turpan Basin, Shan asked by the instantaneous wind of 12 wind attack, accompanied by dust in some areas. This large hurricane caused extensive property damage, six people were killed, 44 missing and 256 injured. May 19 morning, the wind suddenly attacked in northern Xinjiang, Alashankou, Tacheng and other air regions wind up 9-10, instantaneous wind speed of 32 meters per second, other regions winds up 6-7. Winds toppled trees, power lines were Guaduan part of the site. 1999: April 3 to 4, two consecutive days in Hohhot sustained winds and dust storms occur. The range of dust storms in the western region from the Inner Mongolia Autonomous Region has been to the south east of Tongliao City, instantaneous wind speed 16 meters per second. Yikezhaomeng Dalate Banner Wind up to 10. 2000: March 22 to 23, a large area of Inner Mongolia dust storms, part of the dust carried by wind to Beijing over the extent of increased Jansa. March 27, another sandstorm hit Beijing, the instantaneous wind in some areas reached 8-9. An Xiang in the district is a two-story roof of the seven construction workers were scraped wind, two died on the spot. Some billboards were blown down by strong winds, injured pedestrians, smashed vehicles. 2002: March 18 to 21 range since the 1990s, the largest intensity of the strongest, hardest, longest process of dust weather in northern China attacked more than 140 million square kilometers of land, affecting the population 130 million. March 12, 2010, the first outbreak in Xinjiang Hotan Prefecture strong dust storms this year, some counties appear dark and stormy, some local people said the most serious visibility is almost zero. As of 19:00, Hotan city or dim one. 18:00, strong dust storms has to Cele is expected to reach 21 o'clock Minfeng County, covering an area of more than 500 kilometers. At 18:00 on March 19th, 2010, South Xinjiang Basin, northern and eastern, central and northern Qinghai, local, central Gansu, Ningxia, northern Shaanxi, north, central and western Inner Mongolia, Hebei, northwest blowing sand or dust storms occur, including Inner Mongolia Ejinaqi , Haili Su, Linhe, Wulatezhongqi cold Qinghai Lake and there is less than 500 meters visibility and strong storms. April 24, 2010, the third time in Gansu suffered this year, the process of regional dust storms. Dunhuang, Jiuquan, Zhangye,[url=http://www.uggsaleuks.co.uk/][b]title=UGG Sale UK[/b][/url], Minqin in 13 regions of dust storms, dust storms and exceptionally strong dust storms, which Minqin visibility in the evening the same day close to 0 meters. Statistics show that the wind is particularly strong dust storm since meteorological records Minqin strongest one. Because accurate and timely local weather forecasters, weather disasters, causing no casualties Minqin County, due to strong winds caused 13 fire was also extinguished in time. A Right Banner in Inner Mongolia, 34 years the strongest local agriculture and animal husbandry was a dust storm that hit. Alashan preliminary statistics show that: disappearance or death of livestock currently 4,000 long, nearly 5 million acres of farmland affected; Hundreds of serious damage to greenhouses; more than 300 wells have been buried; communications, optical lines were badly damaged. April 26, 2010, Baoding, Shijiazhuang, Hengshui, Xingtai, Handan and Zhangjiakou region has experienced strong winds hit 76 cities and counties, the maximum wind speed of 30 m / s, wind is 11. Jidong dust storms occur 13 counties, 12 counties thunderstorms, which Pingxiang, wide cases, Granville County, there is less than 500 meters visibility sandstorm. 27 morning, the reporter learned from the Gansu Provincial Civil Affairs Department, the latest news, Wuwei, Gansu and other six cities suffer from strong dust storm disasters, according to statistics a total of 937 million yuan in direct economic losses. Dust weather concepts, the concept of rules and standards for dust weather satellite photosAustralian dust storm
dust weather into dust, blowing sand, dust storms and dust storms four. Dust: dust, sand evenly floating in the air, the horizontal visibility is less than 10 km of weather phenomena; Jansa: the wind blowing the dust of the ground, the air very cloudy, the level of visibility in the 1-10 km within the weather phenomenon; dust: dust and strong winds will be blowing a lot of ground, the air is very turbid, horizontal visibility is less than 1 km of weather phenomena; strong dust storm: the wind blowing the dust of the ground, the air blurred, muddy bear, the level of visibility less than 500 meters of weather phenomena. Dust weather dust weather process classification process is divided into four categories: floating dust weather process, the process of blowing weather, dust storms and strong sandstorms during the process. Dust weather process: the process in the same weather, our weather in the region five or more countries the basic (standard) on the same observation times there has been floating dust weather; the process of blowing weather: the weather in the same process, China's weather forecast in the region five or more countries the basic (standard) on the same observation times there has been blowing weather; dust storm process: the process in the same weather, our weather in the region for more than 3 or 3 National Basic (quasi-) on the same observation times when dust storms occurred; strong sandstorm process: the process in the same weather, our weather in the region three or more countries the basic (standard) on the same observation times there has been strong sandstorm. 1 Weather Alert issued dust standard, decision-making services are expected within the next 24 hours there will be dust weather occurs, the in-house bulletin, special reports and making decisions to publish material dust weather. 2, the public forecast national standards: the next 24 hours will occur during dust weather, and the larger sphere of influence or impact on the Beijing-Tianjin region, the dust released to the public alarm. ; Is expected within the next 24 hours will be during storms or strong sandstorm occurred, and have had severe effects, dust released to the public alarm. Provincial standards: by the provinces (autonomous regions and municipalities), Bureau of Meteorology determined with reference to national standards. Description: 1, standard provincial report released dust weather warnings CMA record. 2, the dust weather forecasts, weather warnings should include the area of dust occurred, time, intensity, and the possible impact of countermeasures. 3, the Central Meteorological Observatory of dust weather warnings to the public through effective and timely manner before the provincial meteorological observatory to inform the provincial meteorological observatory dust weather warnings to the public through effective and timely manner before the Central Meteorological Observatory and the meteorological station informed. Sandstorm Sandstorm causes and physical mechanism causes are conducive to creating high winds or strong winds the weather situation, favorable sand, dust and air source distribution and favorable conditions of instability or strong sandstorm sandstorms of the Gobi Desert dust storms formas the main reason. Wind power is generated by dust storms, sand, dust source is the material basis of dust storms and unstable thermal conditions are conducive to wind increased, the development of strong convection, and thus more dust entrainment and winch higher. In addition, the pre-drought, the weather warming, the temperature rose, is a special form of dust weather and climate background; the ground before the cold front, convective cells develop into a squall line clouds or dust storms are conducive to the development and strengthening of small and medium-scale system ; help speed increase of the role of terrain conditions that narrow tube, is one of the conditions conducive to the formation of dust storms. Soil, sand is the main component of Portland, when drought and warmer temperatures, the silicate surface of the silica lost water, H2SiO4 = SiO3 -2 + H2O (gas) ↑ such micelles silicate soil, sand the surface will be a negative charge, with the repulsion between each other, as aerosols can not gather together to form the Young sand that is dust. Sandstorm is essentially a negatively charged silicate aerosols. The physical mechanism of the formation of dust in a very favorable environment for large-scale, dry and cold high-altitude jet stream and strong vertical wind speed, wind shear and thermal stratification conditions of instability, causing front zone generated around the small-scale system development, before and after increasing the front area pressure, temperature gradient, forming a frontal zone before and after the huge pressure gradient. Downstream gradient in the momentum deviation and the joint action of the wind, so that near-surface wind speed and renewed, dust off the surface, the formation of sandstorms or strong sandstorms. Sandstorm major hazards approach ⑴ strong winds: strong winds carrying sand and dust to destroy buildings and public facilities, resulting in human and animal casualties. ⑵ buried in the sand: the sand flow fields caused by the way, channels, cottage, railway, pastures are a lot of sand buried, especially in the transport poses a serious threat. ⑶ wind erosion: every time the dust source and dust storms will affect areas subject to different levels of wind damage, wind up to a depth of 10 cm. It is estimated that China's annual dust storms generated by the loss of soil up to 106 fine-grained material ~ 107 tons, of which most of the particle size of 10 microns or less, the source area of farmland and pasture land productivity, causing serious damage. ⑷ air pollution: sources and effects of the dust storm area, the atmosphere of respirable particulate matter (TSP) increased
sandstorm
, air pollution levels. In 1993, March-April 2000, the impact of dust storms in Beijing by air pollution index reaches Grade 4 have 10 days, while affecting many cities in eastern China. March 24-30, including Nanjing, Hangzhou, 18 cities, including pollution index over four days. Black Wind Black Wind harm the main hazards are the two wind the second is the sand. Wind hazards are twofold: First, wind damage, and second, scraping land erosion. Strength is great. Let me wind damage. Wind damage to buildings, fallen or uprooted trees, poles, tore up the farmers and farm film plastic greenhouses and so on. In addition, Northwest Territories April and May is the fruits, vegetables, sugar beet, cotton and other crops germination, growth, cotyledon or true leaf stage and flowering fruit trees, this time playing the most intolerant of wind and sand. Ranging from leaf dust, so that photosynthesis decreased, and the impact of breathing, reduced crop yields; seedlings died while in flowers, it is much less mature results. For example, May 5, 1993 Black Wind, the Northwest Territories 85 000 fruit flower was knocked, 109,400 shelter and timber broken or uprooted. In addition, strong winds knocked down power poles stoppage, affecting industrial and agricultural production. May 5, 1993 Black Wind caused by the electricity, water, only a Jinchang Jinchuan has caused economic losses of 83 million yuan. Wind acting on the loose soil, arid regions will scrape off the topsoil layer, called the wind. For example, May 5, 1993 Black Wind erosion depth of ten centimeters on average (up to 50 cm), average per acre is 60-70 cubic meters of fertile topsoil is blown away. In fact, strong winds not only blow away the clay and soil organic matter in the small, but also bring sand accumulation in the soil, the soil fertility is substantially reduced. In addition, winds will be the folder sand rubbed off a layer of surface buildings and crops, called erosion, but also a disaster. Sand is sand buried the main hazards. As mentioned above, narrow tube, such as wind and terrain uplift, because the wind speed, wind erosion and sand hazards mainly, concave depression in the lee of terrain such as small wind, sand is sand hazards are buried. For example, May 5, 1993 Black Wind buried in the place where sand, sand buried the average thickness of 20 cm thick at the most reach 1.2 meters. More importantly, the loss of human life. For example, May 5, 1993 death of 85 Chinese Black Wind, 264 wounded, 31 missing people. In addition, death and loss of livestock 120 000, 560 hectares of crops affected, the lifeblood of arid regions buried in the sand drains total length of more than 2000 kilometers, Lan-Xin Railway outage 31 hours. The total economic loss of more than 540 million yuan. Wind and sand storms is an interaction between severe weather phenomena, its formation and global warming, El Niño, forest dropped, vegetation destruction, species extinction, climate anomalies and other factors are inter-related. Among them, the population explosion caused by over-exploitation of natural resources, excessive deforestation, over-cultivation of land is the main reason for frequent dust storms. Therefore, we need to open more land to reduce the causes of dust storms in the formation of four conditions need to have. First, the dust on the ground substance. It is the material basis for the formation of dust storms. Second, the strong winds. This is the driving force to form the basis of dust storms, dust storms can also guarantee long-distance transmission of power. Third, unstable air condition. It is important that the local thermal conditions. Dust storms occurred in the afternoon, evening shows the importance of local thermal conditions.giant dust storm
sandstorms originated in Lanzhou soil erosion, according to Xinhua News Agency Xinhua in Cold and Arid Regions Environmental and Engineering Research Institute expert's efforts, a starting material for the study of dust, and set up special transmission mechanism Wind tunnel simulation of dust storms has successfully completed. By experiment, experts found that soil erosion is the most important part of the development of dust storms. Wind is the most direct driving force of soil, including the nature of air, wind speed and size, the role of wind erosion during wind-related conditions are the most important factor. Another impact of soil moisture is a major reason for soil erosion. The experiment also shows that plant dust control measures are effective methods. Experts believe that the plants are usually three forms to influence the wind: the wind scattered some momentum on the ground, reducing the transfer between the airflow and dust; to prevent soil, dust and other sports. In addition, experimental researchers have come to a conclusion: dust storms not only under specific conditions, the product of the natural environment, and the corresponding relationship with human activities. Man of overgrazing, deforestation, vegetation, man-made construction, especially mining transport over land clearing ground vegetation damage, disturbance on the ground structure, a large area of land desertification, dust storms directly accelerated the formation and development. Sandstorm Sandstorm culprit culprit: atmospheric circulation Beijing spring dust storms occurred a short scene, just north China stretching about 30 million square kilometers of the Loess Plateau in three million years, the weather every year through the process, the difference is , the latter stronger wind, windy longer (can last a few days), the source of dust is not 50 meters away at the crossroads, but hundreds of kilometers of desert and Gobi. Just as God playing a bizarre game: he northwest China and Central Asia and the Gobi Desert start from the surface of the dust blows southeast, despite the accumulation of dust falling from a high place gradually. This game from about 240 million years ago began, God has this way (2002, In fact, the wind is throwing sand in the hand of God. Indian plate and Eurasian plate moving northward collision of India into the Asian continental crust under the continental crust, and the latter backwater up. Shallow Himalayan region to disappear, the Himalayas began to form and gradually rise gradually, the Tibetan Plateau is also the Indian plate compression uplift them. This process lasted more than 60 years later, to about 2.4 million years ago, more than 2,000 meters of the Qinghai-Tibet Plateau. Tremendous changes in surface morphology directly change the atmospheric circulation pattern. Prior to this, the Chinese mainland east of the Pacific, north and south of Siberia were shallow Himalayan region occupies the west side of the Mediterranean at the time stretching from Central Asia far, so smooth most of the Chinese mainland can get enough warm moist ocean air, the climate warm and humid. Northwestern China and Central Asia sub-tropical regions mostly inland, and no large-scale desert and Gobi.sandstorm
But what the Indian Ocean toward the Himalayas blocked the northward moving warm air mass over time, more and more arid northwest of China, giving rise to a large area of desert and Gobi. Here is the accumulation of dust from the Loess Plateau, the birthplace of those. Huge volume of the Tibetan Plateau just stands in the northern hemisphere westerlies, the 240 million years, its height increasing with. Width of the plateau about one-third of the westerlies, the near-surface layer of westerlies into north and south two. East along the south side of the Himalayas, the South Branch flows from the north branch of the northeast edge of the Tibetan Plateau began to flow eastward, this high-altitude air year-round presence in the 3500-7000 m altitude, as the main driver of dust removal. At the same time, the Qinghai-Tibet Plateau uplift, monsoon has also been strengthened, blowing from the northwest and southeast of the winter westerly winds along, in the Loess Plateau in northern China have created a. Inland in northwestern China and Central Asia and the Gobi desert, due to drastic changes in temperature of the hot and cold, where the crack rock collapse more quickly than elsewhere, as debris, diameter of the order by geologists into them: gravel (greater than 2 mm), sand (2-0.05 mm), silt (0.05-0.005 mm), clay (less than 0.005 mm). Clay and silt particles, can be brought more than 3,500 meters of altitude, into the westerlies, westerly jet was moving southeast, along the Yellow River, until gradually falling down. Three million years, this piece of the Asian region from the northwest to the southeast sand handling process never stopped, the sand is just a lot of the whereabouts of the region where the Loess Plateau region, even the Mountain, Taihang Mountains and other mountain top in North China has many loess. Of course, in northern China, including several rivers including the Yellow River valley and the numerous effects of surface erosion and accumulation of loess opposite effect, otherwise, the Loess Plateau will not be doing now, not more than 409.93 m thickness. Taihang Mountains to the east of the settlement of the North China Plain is sandy area, but here is a sinking area, while the development of many rivers, so the falling sand or washed away by rivers or on the sediment brought by rivers was buried. There are hundreds of ancient China at about plug, sand fell from the sky like rain. This record is actually dust. Rain mainly in the Loess Plateau where soil and near. Ancients to such things as singular catastrophic phenomenon, I believe this is the Jin Zhang compiled the natural history of the mind are: 1999, two days in our country as much as 60 times more dust storms. CAS Academician Liu Dongsheng, Loess Plateau should be said that a laboratory dust storms, the lab has accumulated dust storms over the past few hundred million years of records. Gobi Desert in northwest China and the diffuse sky to sprinkle sand over every year in the Loess Plateau on the left a thin layer of loess. The dangers of dust storm dust storms in Northwest China and North China is the northern regions of strong severe weather, can cause houses to collapse, traffic disruption or interruption of power supply,[url=http://www.style-jackets.com][b]title=Moncler Coats[/b][/url], fire, casualty and other livestock, pollution of natural environment, destroying crops,Sandstorm
to the national economy and people's lives and property caused serious damage and great harm. Sandstorm damage mainly in the following areas: environmental degradation occurs when the wind wrapped sandstorm sand, dust everywhere filled the air, all through the regional air pollution, the nose fans eyes, respiratory and other diseases increase. Such as the May 5, 1993 in Jinchang city of strong sandstorm, monitored outdoor air dust concentration of 1016 mm / cubic centimeter, interior is 80 mm / cm, exceeding the national life of dust concentration in the region the standard 40 times. Production life of the affected lot of dust carried by dust storm blocks out the sun shade, overcast weather, resulting in reduced solar radiation, a few hours to ten hours poor visibility, easy to make people feel boring, work and study efficiency. Light pollution can make a large number of animals suffering from respiratory and gastrointestinal diseases, will lead to a lot of serious Sandstorm will make the surface layer of soil erosion, desertification intensifies, covering the leaf surface of the thick dust, affecting normal photosynthesis, resulting in crop production. Sandstorm also allows temperature dropped sharply, propped up the sky like a parasol, on the ground in the shadow becomes dark, cold. Loss of life May 5, 1993, in Jinchang City, Gansu Province, Wuwei, Minqin County, Wuwei City, Silver City and other cities of the strong sandstorm, affected 253.55 million mu of farmland, loss of trees, 42 800, resulting in direct economic losses of 236 million killed 50 people, injured 153 people. April 12, 2000, Yongchang, Jinchang, powerful, strong dust storms in Minqin weather and other cities, according to incomplete statistics only Jinchang, two mighty cities direct economic losses of 15.34 million yuan. Impact on road safety impact on road safety (aircraft, trains, cars and other traffic) dust storms often affect traffic safety, causing the aircraft does not take off or landing, so that cars, train cars glass breakage, outage or derailment. Harm to human health when people are exposed to the weather when dust containing toxic chemicals, bacteria and other layers of protection through the dust into the mouth, nose, eyes, ears. These contain a large number of hazardous substances, if not promptly clean up the dust will cause damage to these organs or organ invasion of bacteria to these points, triggering a variety of diseases. Level of intensity of dust storms is divided into four grades: grade ≤ 1,4 ≤ 6 speed grade, 500 m visibility ≤ ≤ 1000 m, known as weak storms; level ≤ 2,6 ≤ 8 speed grade, 200 m ≤ ≤ 500 米 visibility , called the moderate-intensity storms; 3, wind speed ≥ 9 level, visibility of 50 meters ≤ ≤ 200 m, is called a strong sandstorm; 4, when it reached maximum intensity (instantaneous maximum wind speed ≥ 25 m / s, visibility is ≤ 50 m, even reduced to 0 m), known as an exceptionally strong sandstorm (or black storm, commonly known as Dust weather dust weather process classification process is divided into four categories: floating dust weather process, the process of blowing weather, dust storms and strong sandstorms during the process. 1, the floating dust weather process: the process in the same weather, China weather forecast area for more than five or five countries, the basic (standard) on the same observation times when the dust weather occurred; 2, the process of blowing weather: at the same time weather process, China weather forecast area for more than five or five countries, the basic (standard) on the same observation times there has been blowing weather; 3, dust storms process: in the same weather process, the Chinese air within the forecast area three or more countries the basic (standard) on the same observation times when dust storms occurred; 4, strong sandstorm process: the process in the same weather, China weather forecast in the region three or more countries of the basic ( standard) on the same observation times there has been strong sandstorm. In a very favorable environment for large-scale, dry and cold high-altitude jet stream and strong vertical wind speed, wind shear and thermal stratification conditions of instability, causing front zone generated around the small-scale system development, before and after increasing the frontal zone pressure, temperature gradient, frontal zone formed around the huge pressure gradient. Downstream gradient in the momentum deviation and the joint action of the wind, so that near-surface wind speed and renewed, dust off the surface, the formation of sandstorms or strong sandstorms. Sandstorm in the ecosystems, the role ofterrible sandstorm
While many dust hazards, but the whole process of dust storms, but also natural ecosystems are indispensable in part, for example, the red sandstorm in Australia clip brought a lot of iron Antarctic sea plankton has proven to be important source of nutrients, and phytoplankton can also consume a large amount of carbon dioxide, in order to reduce the dangers of the greenhouse effect, so the impact of sandstorms level is not all negative. Perhaps in another level, in response to the Earth dust storms may also be a symptom of environmental change, as we have a cold cough occurs in the trachea in order to rule out as waste. To provide for the study of sandstorms, and other nutrients in the Tasman Sea and so many effects, the climate in Australia has brought together many scholars. They found that the red quartz sediments sandstorm in Australia can be found in New Zealand and New Zealand but fertile land; so that Australian dust storms caused by the loss of nutrients can result in New Zealand is the land of nutrients harvest. And like Hawaii fertile soil sediment data can be based on an analysis of the nutrients that have many components is far from the Eurasian mainland. Because the two separated by thousands of miles, not the ordinary wind blown dust inland so far away, so it is dust, but the fine dust containing nutrients to carry on the 3000 meters above the ground, across oceans, and then planting them generally spread down. In addition to the Hawaiian Islands, the scientists also found that earth's largest green lung also benefited from the Amazon Basin rainforest dust storms, it is an important nutrient source is the air dust. Rock dust can become lush secret is that dust aerosols containing iron ions contribute to the composition of plant growth. Furthermore, since the birth of more dust storms of high salinity in the dry land, dust storms among the backdrop of some of the soil particles often with some alkaline substance, it can often reduce acid rain, dust storms near the settlement area of the role or the role of soil acidification. Institute of Atmospheric Physics, Chinese Academy of Sciences of Mr. Wang Zifa said: - + 2 H + = H2SiO3 ↓ dust and soil particles in precipitation in northern China and the role of the PH value of 0.8-2.5 increase in South Korea increased 05.-0.8, 0.2-0.5 increase in Japan, if not the role of dust, then many northern areas of acid rain damage to much more serious. But we should be more actively look for abnormal frequency of dust storms occurring mechanism to really solve the abnormal climate change harm the environment. Sandstorm treatment and preventive measures (1) Strengthen the protection of the environment, the protection of the environment that the height of the legal system. (2) restoration of vegetation, wind storms to strengthen the prevention of biological protection system. Implemented to protect and restore the vegetation cover, to prevent the further expansion of land desertification, to minimize dust sources. 3, according to local conditions in different parts of the development of disaster prevention, disaster, disaster planning, and actively promote a variety of mitigation techniques, and build a number of demonstration projects, to point, gradually extended to further improve regional integrated defense system. 4 control population growth, reducing the pressure of human factors on the land, protecting the environment. Related articles：
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