How sandstorms hit some provinces and cities in my country and what prevention and control measures our government took in the 20th century

Strong sandstorms in my country in the past 50 years

In the second half of the 20th century, my country showed a rapid upward trend:

*** occurred five times in the 1950s;

Terrorism occurred 8 times in the 1960s;

Terrorism occurred 13 times in the 1970s;

Terrorism occurred 14 times in the 1980s;

*** happened 23 times in the 1990s!

In 1979, there were three sandstorms in the Tarim Basin between April and June. In one of them, an average of 25,600 tons of dust fell per square kilometer in three days in Yuli County alone;

< p>In 1983, the Shihezi Reclamation Area in Xinjiang was hit by a sandstorm, affecting 250,000 acres of crops and causing direct economic losses of more than 3 million yuan;

In May 1986, a magnitude 10 wind swept through Hotan, damaging 200,000 acres of crops. 10,000 acres, direct economic losses of more than 50 million yuan;

In May 1993, a strong sandstorm occurred in the northwest region, causing the death and loss of 120,000 livestock (only), and 5.05 million acres of crops were affected. 380 people died, with a direct economic loss of 540 million yuan;

On May 15, 1995, a huge sandstorm in Gansu Province caused a dustfall of 12.431 million tons, equivalent to 15 years of the largest cement factory in the province. Yield;

In April 1998, 12 prefectures and states in the northwest were hit by sandstorms, 461,000 acres of crops were affected, 110,900 livestock died, 1.56 million people were affected, and direct economic losses were 800 million yuan. ...

In March 2000, a sandstorm hit Beijing, with instantaneous winds reaching level 8 to 9 in some areas. Seven workers who were working on the roof of a two-story building in Anxiangli Community were blown off by strong winds, and two died on the spot. Some billboards were knocked down by strong winds, injuring pedestrians and damaging vehicles.

The frequent occurrence of sandstorms in my country is consistent with the pace of desertification expansion:

In the 1950s and 1960s, desertified land expanded by 1,560 square kilometers per year;

70 to 80 In the 1990s, desertified land expanded by 2,100 square kilometers per year;

In the 1990s, desertified land expanded by 2,460 square kilometers per year. Sandstorms are an alarm for land desertification, and the increase in the frequency and intensity of sandstorms is a wake-up call for an ecological crisis!

Meteorological experts remind people to pay attention when traveling in sandy weather.

First of all, be careful not to walk or ride in the narrow passages between high-rise buildings. Because the long and narrow passage will form a "narrow tube effect", the wind force will increase in the passage, which will bring certain dangers to pedestrians walking in it.

Second, be careful not to stay under billboards and old trees for a long time. Some billboards are not firmly installed and may collapse under strong winds; some old trees are dead and have weak foundations, and are very likely to break in strong winds, posing a danger to pedestrians.

Third, pay attention to the safety of light vehicles. Since light vehicles are lightweight, they may be blown up by strong winds while driving at high speeds. So put some heavy objects on the light vehicle or drive slowly.

Fourth, we should pay attention to riding bicycles as little as possible. Because in windy weather, although the tailwind or headwind will not cause much danger to cycling, once riding in the crosswind direction, it is very likely to be blown down by the strong wind and cause physical injury.

Fifth, be careful to carry dust-proof supplies such as masks and gauze to prevent sand and dust from causing damage to the eyes and respiratory system.

The moving paths and main areas of impact of sandstorms in my country:

Of the 32 sandstorm events monitored in my country last year, 18 of them formed in southern Mongolia and then moved into my country. , accounting for 56% of the total number of visits throughout the year. A sandstorm that originated in the desert area of ??eastern Kazakhstan in September 1998 passed through a vast area in northern my country and transported a large amount of sand and dust at high altitudes to North America.

The dust weather in northern my country in spring is accompanied by strong winds caused by cold air activity. There are three main paths for cold air to affect our country:

East Road: southward from the eastern and central part of Mongolia , affecting northeastern my country, eastern and central Inner Mongolia, Shanxi, Hebei and the south;

Middle Road: from central and western Mongolia to the southeast, affecting central and western Inner Mongolia, eastern northwest, central and southern North China and south Region;

West Route: Moving southeast from western Mongolia and northeastern Kazakhstan, affecting northwest, north and south China including Xinjiang.

Analysis of the observation results of meteorological stations in the past 50 years shows that blowing sand and sandstorms have occurred in most areas north of the Yangtze River in my country, with the northwest region being the most prominent. Dust-prone areas are mainly concentrated around the Tarim Basin, the Dunhuang-Hexi Corridor-Ningxia Plain-Northern Shaanxi line, the Alxa Plateau, the Hetao Plain and the Ordos Plateau in Inner Mongolia.

In recent years, desertification and sandstorms have become increasingly serious in my country. The desertification area has grown from more than 1,560 square kilometers per year in the 1950s and 1960s, to 2,100 square kilometers in the 1970s and 1980s, to 2,460 square kilometers in the 1990s, and now to 3,436 square kilometers.

Every year, desertification devours land equivalent to a medium-sized county, causing direct economic losses of more than 50 billion yuan. What is even more serious is that sandstorms caused by desertification are becoming increasingly frequent. Not only are sandstorms severe in Beijing, but most northern cities such as Xi'an and Shenyang are also being hit by sandstorms. In recent years, spring sandstorms have affected Nanjing, Shanghai and other places. In the past, sandstorms mainly occurred in spring, but now blowing sand and sandstorms occur even in winter. The "yellow snow" that appeared in some areas last winter is an example.

There are two causes of desertification and sandstorms. One is natural factors, especially in recent years, La Ni?a (anti-El Ni?o, "El Ni?o" phenomenon is near the equator of the United States, from about 4 degrees north latitude to south latitude. 4 degrees, the abnormal warming phenomenon in the seawater zone between 150 degrees and 90 degrees west longitude, with an amplitude of thousands of kilometers, may be caused by the heating of volcanic eruptions at the bottom of the Pacific Ocean or the lava spewed from the crustal fractures, which caused the warming of the ocean currents, which in turn caused the signal. The wind weakens and reverses. Others speculate that it may be caused by the uneven annual speed of the earth's rotation. Whenever the annual speed of the earth's rotation changes from acceleration to deceleration, the worrying El Ni?o phenomenon occurs. Yes, the El Ni?o phenomenon is becoming more and more frequent. It was originally thought to occur once every five, seven or even ten years, and then it appears every three to seven years. However, it seems to occur every two or three years since the 1990s. The emergence of phenomena, global climate warming and continued drought caused by greenhouse gas emissions; second, irrational human economic and social activities, such as indiscriminate reclamation, overgrazing, overexploitation, indiscriminate logging, and abuse of water resources are the main impacts of land desertification factor. Its formation process is induced by human activities, the interaction between natural factors and human factors, and the result of continuous vicious feedback.

Measures: Countries in source areas provide financial subsidies to farmers and return farmland to pasture and forest. Through a variety of preferential measures, collectives and individuals are encouraged to prevent and control desertification; the construction of protective forests in border areas; the "Three North Protective Forest Project", "Rim Beijing Protective Forest Project", etc.