Causes of sandstorm weather in Beijing

Sandstorms originate from soil wind erosion.

According to Xinhua News Agency, Lanzhou Electric Power Co., Ltd., with the efforts of experts from the Institute of Environment and Engineering in Cold and Arid Regions, Chinese Academy of Sciences, recently successfully completed a sandstorm wind tunnel simulation experiment specially designed to explore the mechanism of sandstorm initiation and propagation.

Experts found through experiments that soil wind erosion is the primary link in the occurrence and development of sandstorms. Wind is the most direct driving force of soil, among which the nature of airflow, the magnitude of wind speed and the related conditions of wind action in soil wind erosion are the most important factors. In addition, soil water content is also one of the important reasons that affect soil wind erosion.

This experiment also proves that plant measures are one of the effective methods to prevent and control sandstorms. Experts believe that plants usually affect wind erosion in three forms: dispersing certain wind momentum on the ground to reduce the transmission between airflow and dust; Stop the movement of soil, dust, etc.

In addition, through experiments, the researchers concluded that the occurrence of sandstorms is not only the product of specific natural environmental conditions, but also has a corresponding relationship with human activities. Man-made overgrazing, deforestation, industrial and mining traffic construction, especially man-made overgrazing, destroyed the ground vegetation, disturbed the ground structure, formed a large area of sandy land, and directly accelerated the formation and development of sandstorms.

The culprit of sandstorm: atmospheric circulation

The brief scene of spring sandstorm in Beijing is just a weather process that has been experienced every year for two or three million years on the Loess Plateau, which stretches for about 300,000 square kilometers in the north of China. The difference is that the wind in the latter is stronger and the wind lasts longer (it can last for several days). The source of sandstorm is not the crossroads 50 meters away, but the desert and Gobi hundreds of kilometers away.

It's like God is playing an incredible game: he grabs the dust on the surface of deserts and Gobi in northwest China and Central Asia and throws it to the southeast, leaving a highland where the dust falls. This game started about 2.4 million years ago, and God is still enjoying it (in 2002, Nature published the latest research results of China scholars, pushing the start time to 22 million years ago).

In fact, the wind is God's hand that throws sand.

During the period of 1966- 1999, there were 60 sandstorms lasting more than two days in China. Academician Liu Dongsheng of the Chinese Academy of Sciences thinks that the Loess Plateau should be regarded as a laboratory for sandstorms, which has accumulated records of sandstorms for millions of years. Sandstorms from the northwest desert and Gobi are scattered all over the sky, leaving a thin layer of loess on the Loess Plateau every year.