How horrible is the dusty weather?

Generally speaking, sandstorm is a kind of storm with many sandstorms, which usually occurs in desert and arid climate areas. However, in the practical sense of scientific research, sandstorms have strict indicators. In astronomy, sandstorms and sandstorms are generally distinguished by visibility: thus, sandstorms can be seen below 1km, and sandstorms and dusty weather can be seen above 1km. The authoritative experts of China Natural Environment Monitoring Station take the concentration of suspended solids in the air as the evaluation index. Recently, the concentration of suspended solids in Beijing's dusty weather generally does not exceed 1000mg/m3, but the concentration in the dusty temperature far exceeds this index value.

Authoritative experts stressed that it is necessary to distinguish between three common weather conditions: sand dust, sand blowing and sandstorm. At the temperature of floating dust temperature, dust floats in the air, and most of the floating dust comes from the road surface. The sand rolled up in floating sand weather is completely local. Dust temperature takes into account both dust and dust weather conditions, but the ratio of them changes to some extent. When the dust temperature reaches a certain level, it can be called dust storm.

The induction of dust temperature is helpful to produce strong winds and windy weather conditions, and favorable dust diffusion, dust source diffusion and favorable gas instability standards are the important reasons for dust temperature.

Strong wind is the driving force of sandstorm, and the source of sandstorm is the material condition of sandstorm Unstable heating standards are conducive to the expansion of wind speed and the strong development trend of sandstorms, which produce a large number of sandstorms and roll up very high. In addition, early drought, global warming and rising temperature are the unique climatic conditions for sandstorms.

The development trend of ground cold front is cloud, and its shape is small and medium-sized limit system software which is beneficial to the development trend and strengthening of sandstorm. The topographic standard conducive to improving the shape is the narrow tube effect, which is one of the resource advantages of sandstorms.

Under the extremely favorable standards of super-scale natural environment, high-altitude wet and cold jet, strong vertical cyclone, wind frequency switching and thermal instability stratification, the physical system generated by sandstorm has created the generation and development trend of small and medium-sized system software around the front area, expanded the standard pressure temperature field around the front area, and produced great pressure and temperature gradient directions. The driving force is the same as the frequency of oblique wind. The rock stratum near the geological structure becomes steep, which blows up the sand in the soil layer, resulting in the temperature and strong sand.

Important hazards of sand and dust disasters: Strong winds accompanied by fine sand and floating dust destroy buildings and public facilities, causing deaths. Burying sand: Dust flow is buried in various quicksand such as fields, canals, cottages, railway lines, lawns, etc., which is especially harmful to traffic and travel.

Soil wind erosion: the source area and hazard area of each sandstorm will be weathered to varying degrees, and the deep weathering can reach 1~ 10cm. At present, the annual damage of aeolian sand to fine sand in soil layer in China is about 106 ~ 107 tons, most of which are below 10 micron in diameter, which seriously harms the main production forces of land resources such as fields and lawns in the source area. Environmental pollution: In areas with sandstorms and hazards, yellow fever (TSP) caused by inhaling particles in the air is increasing day by day, and environmental pollution is getting worse.

The first is the problem of wind disaster. Strong winds will destroy buildings, blow down or pull out flowers and trees, and destroy plastic greenhouses in farmhouses and plastic films in fields. In addition, April and May in the western region are just the season when fruits and vegetables, Chinese cabbage, cotton wool and other crops germinate, so young leaves and leaves grow and develop, and peach blossom period is the least tolerant to dust. If it is light, the leaves will be covered with dust, and the photosynthesis of plants will be weakened, which is harmful to inhalation and reduces the yield of crops. If it is heavy, the seedlings will die and will not mature. For example,1May 5, 1993, the black wind blew down the flower cores of 5,000 fruit trees in the western region, and 109400 shelter forests and raw material forests were broken or uprooted. In addition, the strong wind blows down the poles, causing water and electricity cuts, endangering industrial and agricultural production and manufacturing. 1On May 5, 993, due to the failure of black wind power, Jinchang Jinchuan Company alone caused property losses of 3 million yuan.

When strong winds act on the soil layer in arid areas, the subsoil is scraped off, which is white weathering. For example, on May 5, 1993, the average weathering depth was 10cm (up to 50 cm), in other words, the fertile subsoil with an average yield of 60~70 cubic meters per mu was blown away by the wind. In fact, strong winds will not only scrape away the clay and organic chemicals in the soil layer, but also continue to accumulate the loess layer, greatly reducing the organic matter in the soil layer. In addition, strong winds with sand constantly scrape away the surface of residential buildings and food crops, which is called erosion and also a disaster.

The harm of desertification is mainly caused by sand burial. The above introduces the narrow pipelines, windward protrusions and other landforms. Because of the strong wind, the damage is mainly weathering, but for landforms with small wind and small wind, sand burial is the most important damage. Such as1sandy land blown by black wind on May 5, 1993, with an average foundation depth of 20cm and a thickness of1.2m. ..

Moreover, what is important is the lack of life. For example,1May 5, 993, 85 people were killed, 264 people were injured and 3 1 person was missing. In addition, 6.5438+0.2 million large livestock were killed, 560 square kilometers of food crops were affected, more than 2,000 kilometers of sand were buried in the ditch of Fate Line in arid climate, and the Lanzhou-Xinjiang Railway was shut down for 365.438+0 hours. The total property losses exceeded 540 million yuan.

Dust is a disastrous weather condition of dust interaction, which is related to global warming, El Nino conditions, sharp decline of mountain forests, destruction of plant communities, ecological disasters, climate disasters and other factors. Among these factors, over-exploitation of ecological resources, deforestation and over-reclamation of land resources caused by population explosion are the important reasons for sandstorms. So everyone must reduce cultivated land.