There are three basic conditions for the formation of sandstorm:
First, there should be a source of sand,
Second, there should be strong cold air, i.e. strong wind,
Third, there should be interaction between warm and cold air. The source of sand comes from deserts, degraded forest and grassland, or dry pine land without vegetation cover, as well as the sediment of urban and rural construction sites. The cyclone and the low pressure produce a vertical upward movement, which blows up the dust and forms a dust storm. The weather difference of sand blowing, floating dust and sandstorm is distinguished by visibility in meteorology: the weather with horizontal visibility between 1-10km is sand blowing or floating dust. When the floating dust weather occurs, the air is filled with some small particles, most of which come from other places; the dust rolled up by the floating dust weather is some larger particles, which are basically generated locally. The sandstorm with horizontal visibility less than 1km is a kind of disastrous weather phenomenon, which brings the most serious harm. According to meteorologists, the causes of sandstorm include wind force, high-altitude atmospheric strong convection and surface state, while the former two are climatic factors and irresistible by manpower, so it is impossible to eradicate sandstorm at present.
The wind disaster, sand accumulation and wind erosion caused by sandstorm damage the forest and vegetation, and aggravate the degree of desertification. Meteorological experts remind that the most active and effective behavior of human beings is to strengthen the monitoring and prediction of gale weather, especially in the early drought. Secondly, for Xi'an, a tourist metropolis, there should be quite effective emergency response measures, strengthen management and strengthen preventive measures before unexpected disasters. For the whole province, the most fundamental thing is to carry out comprehensive governance. The whole society should act together to control deserts and improve the ecological environment. While doing well in economic construction, we should pay attention to ecological construction. Every citizen should have a strong sense of hardship and environmental protection, and should strengthen the education in this area, so as to do a good job in afforestation, expand the vegetation coverage, open up resources and reduce expenditure, and make rational use of water resources. Shaanxi, in particular, is the bridgehead of the western development. We should take the implementation of "returning cultivated land to forest (grass), closing mountains and greening, individual contracting, and grain for relief" as the main measures to strive for the early realization of grain to Sichuan, fruit to mountain, grassland to slope, so that the land of Sanqin is green, clear and rich. Gradually restore the natural rich and diverse ecosystem. In this way, maybe in a few decades, the sandstorm will fade into our memory, and our descendants will see a beautiful northwest.