Geographical reasons for frequent sandstorms in Minqin, Gansu Province in spring

This place is located in arid and semi-arid area, with dry climate and little rain. In spring, due to the rapid temperature rise, windy weather, less precipitation and loose soil, it is easy to be blown by the wind. Furthermore, in spring, it moves northward, the solar radiation is strengthened, the temperature rises, the precipitation is scarce, evaporation is vigorous, the surface is more dry and short of water, and the bonding force between sand grains is weakened, resulting in loose topsoil. In addition, during this period, the temperature changes rapidly, cold front activities are frequent, windy weather is more, and sandstorms occur frequently.

Extended data:

Hazards caused by sandstorms:

1, environmental pollution:

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.

2. 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.

3. Loss of life and property

For example, on May 5, 1993, severe sandstorms occurred in Jinchang, Wuwei, Minqin and Baiyin, Gansu Province, which affected 2,535,500 mu of farmland, lost 42,800 trees, caused direct economic loss of 236 million yuan, and killed 85 people and seriously injured 153 people.