What is the effectiveness of the Three-North Shelterbelt?
Spring was beautiful in Beijing yesterday, and in sharp contrast, Beijing encountered strong winds and sandstorms on the 28th.
According to a report from the Beijing Municipal Ecological Environment Monitoring Center, at 8 am on the 28th, the city's PM10 index was generally above 2000, and the air quality reached Grade 6 serious pollution.
The reporter saw that during the day on the 28th, the streets of Beijing were covered in a patch of khaki with visibility less than 2 kilometers.
People on the road wear masks, many of them also wear sunglasses or goggles.
Citizens reported that after staying outdoors for a while, their mouths would be full of earthy smell.
In just half a month, many parts of the north were caught in sandstorms twice in a row.
Meteorological experts said that the dust weather is a problem caused by atmospheric circulation, which mainly originated in Mongolia and belongs to transit sand and dust for my country.
Some netizens asked: "Why is there such a strong sandstorm with the Three North Shelterbelt?"
In this regard, Jia Liming, a professor of forest cultivation at Beijing Forestry University, said that once a sandstorm occurs, after entering the atmospheric circulation, the person walks at high altitude, and the tree height of my country's Three North Shelterbelt is basically below 20m, and it is impossible to block the dust coming from high above.
Zhang Xudong, a researcher at the Institute of Forestry of the Chinese Academy of Forestry, said that the role of shelterbelts is mainly to prevent wind and fix sand. In the face of sandstorms, it can weaken surface wind speed and weaken dust, but it is impossible to affect atmospheric circulation.
"With the Three North Shelterbelt, there will be no sandstorms. This inference is not objective." He said.
Yang Wenbin, chief expert on sand prevention and control at the Chinese Academy of Forestry, said that deserts cannot be eliminated, and the formation of sandstorms is also an irresistible natural phenomenon and cannot be fundamentally avoided.
What we can do is to strengthen the construction of shelter forests, strengthen the ecological protection and restoration of sandy areas, reduce the frequency of sand and dust weather as much as possible, reduce the intensity of sand and dust weather, and reduce the degree of damage by sand and dust weather.
It is understood that the Three North Shelterbelt Project started in 1978, and according to the overall plan, it will be completed in 2050 and will be constructed in three phases and eight phases, with a total construction area of 4.069 million square kilometers.
By the 40th anniversary of the construction of the Three North Project in 2018, 30.143 million hectares of afforestation have been completed, the forest coverage rate has increased from 5.05% to 13.57%, and the volume of standing timber has increased from 720 million cubic meters to 3.33 billion cubic meters.
Jia Liming introduced that the construction of the Three-North Shelterbelt System for more than 40 years, coupled with more than 20 years of returning farmland to forest (grass) project and the Beijing-Tianjin sandstorm source control project, has greatly increased the forest and vegetation coverage in the sandy areas of northern my country. , And innovatively formed the forest vegetation construction technology of "the trees are suitable for trees, the trees are suitable for irrigation, the trees are suitable for irrigation, and the grass is suitable for grass."
“There have been no serious sandstorms for many years, and these key forestry ecological projects have contributed a lot.” Jia Liming also pointed out that my country’s ecological fragility still cannot be ignored. It is necessary to further promote the greening of the country, strengthen the construction of key forestry ecological projects, and develop urban and Rural forest construction and precise improvement of forest quality, "ecological governance will take a long time."
According to Xinhua News Agency