What are the hazards of sandstorms?

Sandstorm is a general term for sandstorm and sandstorm. It refers to a severe sandstorm weather phenomenon in which strong winds blow and drag a large amount of sand and dust on the ground into the air, making the air particularly turbid and the horizontal visibility less than one kilometer. Among them, sandstorm refers to a sand-laden storm formed by strong winds blowing a large number of sand near the ground; Sandstorm is a storm formed by strong winds, which brings a lot of dust and other particles into the sky.

Wind damage: strong winds destroy buildings, blow down or pull up tree stems, tear up farmers' plastic greenhouses and farmland plastic films, etc. In addition, April and May in northwest China are the time when cash crops such as melons, fruits, vegetables, beets and cotton emerge, cotyledons or true leaves grow, and fruit trees bloom, at this time, they are least resistant to sandstorms. Light leaves are covered with dust, which weakens photosynthesis, affects respiration and reduces crop yield; For example, the black wind on May 5, 1993/kloc-0 caused 85,000 pistils of fruit trees to be destroyed in northwest China, and 109400 shelterbelts and timber forests were broken or uprooted. In addition, the strong wind blew down the telephone poles, causing water and electricity cuts and affecting industrial and agricultural production. 1On May 5, 993, the black wind caused power failure and water cut, and Jinchang Jinchuan Company alone caused economic losses of 83 million yuan.

Scraping: When strong wind acts on loose soil in arid areas, it will scrape off a layer of topsoil, which is called wind erosion. For example,1May 5, 1993, the average wind erosion depth of black wind 10 cm (up to 50 cm), that is, an average of 60 to 70 cubic meters of fertile topsoil per mu was blown away by the wind. In fact, strong winds not only blow away the fine clay and organic matter in the soil, but also pile up the sand in the soil, which greatly reduces the fertility of the soil. In addition, the strong wind with sand will wear off a layer of buildings and crops, which is called abrasion and also a disaster.

Hazard of sand: The main hazard is sand burial. As mentioned above, in narrow pipelines, windward and uplifted terrain, due to high wind speed, the wind-blown sand hazard is mainly wind erosion, while in leeward depressions and other terrain with low wind speed, the wind-blown sand hazard is mainly sand burial. Such as1where sand burial occurred in the black wind on May 5, 993, the average thickness of sand burial was 20 cm, and the thickest part reached1.2 m.

More importantly, the loss of human life. For example,1May 5, 993, 85 people were killed, 264 people were injured and 3 1 person was missing. In addition, the death loss of large livestock was 1.2 million, the crops were affected by 5.6 million mu, the total length of the lifeline canal buried by sand in arid areas was more than 2,000 kilometers, and the Lanzhou-Xinjiang railway was stopped for 3 1 hour. The total economic loss exceeded 540 million yuan.

⑴ Strong wind: Strong wind accompanied by dust damages buildings and public facilities, causing human and animal casualties.

⑵ Sand burial: Farmland, channels, cottages, railways, grasslands, etc. are buried by a large number of quicksand in the form of quicksand, especially posing a serious threat to transportation.

⑶ Soil wind erosion: The dust source and affected area of each sandstorm will be harmed by wind erosion in different degrees, and the depth of wind erosion can reach 1 ~ 10 cm. It is estimated that the annual loss of soil fine particles caused by sandstorms in China is as high as 106 ~ 107 tons, most of which are below 10 micron, which seriously damages the land productivity of farmland and grassland in the source area.

⑷ Air pollution: In the source area and influence area of sandstorm, the inhalable particulate matter (TSP) in the atmosphere increases, and air pollution intensifies. Taking 1993 "5.5" sandstorm as an example, the outdoor air TSP concentration in Jinchang, Gansu Province reached 10 16 mg/m3, and the indoor air TSP concentration was 80 mg/m3, exceeding the standard by 40 times. From March to April, 2000, Beijing was affected by sandstorms, and the number of days when the air pollution index reached Grade 4 or above reached 10, which also affected many cities in eastern China. From March 24th to 30th, the daily pollution index of Nanjing, Hangzhou and other cities 18 exceeded Grade IV.