Causes and prevention of sandstorm

The formation of sandstorm weather has three basic conditions:

First, there is sand source,

Second, there must be strong cold air, that is, strong wind.

Third, there should be interaction between cold and warm air. The sand source comes from desert, degraded forest and grassland or dry loose land without vegetation cover, as well as sediment from urban and rural construction sites. Cyclones and low pressure produce vertical upward movement, blowing up dust and forming sandstorm weather. Meteorologically, the differences among sand blowing, floating dust and sandstorm weather are distinguished by visibility: the weather with horizontal visibility between 1 ~ 10 km is sand blowing or floating dust. When there is floating dust weather, the air is filled with some fine particles, and most of the dust comes from other places; The dust rolled up in the sand-blowing weather is some large particles, which are basically produced locally. Sandstorm weather with horizontal visibility less than 1 km is a disastrous weather phenomenon, which brings the most serious harm. Meteorologists said that it is impossible to eradicate sandstorms at present because the causes of sandstorms include wind, strong convection in the upper atmosphere and surface conditions, while the first two are climatic factors and irresistible to human beings.

The wind disaster, sand accumulation and wind erosion caused by sandstorm have destroyed forests and vegetation, and the degree of desertification has intensified. Meteorologists reminded that the most active and effective behavior of human beings in sandstorm weather is: first, strengthen the monitoring and forecasting of windy weather, especially in the early drought. Secondly, for a tourist metropolis like Xi 'an, before the sudden disaster comes, we should have quite effective emergency countermeasures, strengthen management and strengthen preventive measures. The most fundamental thing in the province is comprehensive management. The whole society * * * peers move, desert control, improve the ecological environment. While doing a good job 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 education in this respect, really do a good job in afforestation, expand vegetation coverage, increase revenue and reduce expenditure, and rationally use water resources. Shaanxi, in particular, is the bridgehead of the western development. It is necessary to take the implementation of "returning farmland to forest (grass), closing hillsides to facilitate afforestation, individual contracting, and giving relief by work" as the main measures, and strive to realize the early realization of Sichuan rice, grain, mountain fruit and grass full of slopes, so that the land in Sanqin will be green, the water will be clear and people will be rich. Gradually restore the rich and diverse ecosystems of nature. In this way, perhaps in a few decades, sandstorms will fade out of our memory, and our descendants will see a beautiful northwest.