Why are there so many sandstorms in Beijing?

1, it's hard to say, but it is certain that the sandstorm in Beijing has not disappeared. Sandstorm in Beijing is the product of interaction between natural factors and human activities. Gale weather process, tropospheric instability and surface sand source are the three elements of sandstorm formation in Beijing.

2. Gale weather process and tropospheric instability are natural phenomena, which are beyond people's control and have too many variables. At present, people's understanding of its activity law is still superficial, and it is impossible to accurately predict the medium and long-term trend. So as far as these two factors are concerned, we can't make a trend judgment on sandstorms in Beijing. Surface sand source is not only the result of natural environment evolution, but also the product of human activities.

3. According to the global change trend, the temperature will increase in winter and spring in northern China, the degree of drought will be aggravated, and the degree of surface desertification will be further improved. In this regard, sandstorms in Beijing will tend to strengthen. However, the degree of surface desertification is still affected by human activities. The destruction of surface vegetation by human beings will accelerate the degree of surface desertification, while planting grass by human beings will delay the degree of surface desertification, and even there may be a situation of "people entering the sand and retreating".

4. Because human activities can be controlled by human beings themselves, the degree of surface desertification can be judged according to human activities.

Scientific research shows that the global climate is warming and the greenhouse effect is intensifying, but what we are seeing in Beijing at present is only a microcosm of the global environmental deterioration. China's desertification land area has reached 3.32 million square kilometers, of which the desert area is nearly 6.5438+0.6 million square kilometers, and most of these deserts and deserts are concentrated in the northwest. It is not difficult to understand why Beijing will be the first victim after the sandstorm.

6. Less precipitation in spring is the main reason for more dusty weather. On the one hand, insufficient precipitation causes slow vegetation growth, on the other hand, it also reduces the possibility of direct dust suppression. If the temperature rises too fast, the ice and snow on the ground will melt quickly, but at this time, the vegetation on the surface has not grown out and has not played a role in fixing the surface sand. Another side effect of the rapid temperature rise is that the temperature difference between the ground and the sky causes air convection, which causes the dust on the ground to be rolled up by strong winds and produces dusty weather.

Sandstorm is a weather phenomenon, which refers to a severe sandstorm weather in which strong winds drag a lot of dust on the ground into the air, making the air particularly turbid and the horizontal visibility is lower than 1 km. It needs three conditions: strong wind, unstable weather and sand source. Humans can't eliminate sandstorms yet. The only thing they can do is to control the roughness of the wind and interface, reduce the lift-off of floating dust, and make them unable to run with the atmospheric circulation. Reduce the jumping ability of quicksand, fix sand dunes, prevent desert expansion and protect oases.