What is the cause of sandstorm?
It refers to a severe sandstorm weather phenomenon in which strong winds blow up 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.
The formation of sandstorms requires these three conditions:
One is the dust on the ground. It is the material basis for the formation of sandstorms.
The second is the strong wind. This is the dynamic basis for the formation of sandstorms and the dynamic guarantee for the long-distance transportation of sandstorms.
Third, the air state is unstable. This is an important local thermal condition. Sandstorms often occur in the afternoon and evening, which shows the importance of local thermal conditions.
Sandstorm weather is a disastrous weather in northwest China and northern North China.
It can cause house collapse, traffic power supply blocked or interrupted, fire, human and animal casualties and so on. It pollutes the natural environment, destroys the growth of crops and causes serious losses and great harm to the national economic construction and the safety of people's lives and property. The hazards of sandstorms mainly include the following aspects:
Deterioration of ecological environment
When sandstorms occur, dust and floating dust carried by strong winds are everywhere, and the number of people passing through areas with air turbidity, choking nose and eyes, respiratory tract and other diseases increases. For example,1A serious sandstorm occurred in Jinchang on May 5, 993. The dust content in outdoor air is 10 16 mm/cm3, and the dust content in indoor air is 80 mm/cm3, which is 40 times higher than the national standard for dust content in living quarters.
Production and life are affected.
A lot of dust carried by sandstorm weather blocked the sun, and the weather was gloomy, which led to the decrease of solar radiation. A few hours to ten hours of poor visibility can easily make people feel depressed and reduce the efficiency of work and study. In light cases, a large number of livestock can be infected with respiratory and gastrointestinal diseases, and in severe cases, a large number of "spring-deficient" livestock will die, and fertile soil, seeds and seedlings in farmland will be scraped away. Sandstorm will also aggravate the wind erosion and desertification of the surface soil, cover thick dust on the leaves of plants, affect normal photosynthesis and cause crop yield reduction. Sandstorms also caused the temperature to drop sharply. The sky is like a parasol, and the ground becomes dark and cold in the shadow.
Loss of life and property
1On May 5, 1993, a serious sandstorm occurred in Jinchang, Wuwei, Minqin and Baiyin, Gansu Province, which affected 2,535,500 mu of farmland, lost 42,800 trees, caused a direct economic loss of 236 million yuan, killed 85 people and seriously injured 153 people. On April 12, 2000, serious sandstorms occurred in Yongchang, Jinchang, Wuwei and Minqin. According to incomplete statistics, the direct economic losses in Jinchang and Wuwei alone amounted to15.34 million yuan.
Affect traffic safety
Sandstorms that affect traffic safety (traffic accidents such as airplanes, trains and cars). ) often affect traffic safety, resulting in aircraft can not take off or land normally, cars, train cars break, stop or derail.
Harm to human health
When people are exposed to dusty weather, dust containing various toxic chemicals and bacteria can enter the mouth, nose, eyes and ears through layers of protection. If the dust containing a lot of harmful substances is not cleaned in time, it will cause damage to these organs or bacteria will take these organs as invasion points, causing various diseases.