Research report on sandstorm

1: Hazards of Sandstorms China News Service, Fuzhou1/month18th The air quality in Fuzhou is basically excellent due to the sandstorm in the north on 10 this month. From 12 to 14 this month, the pollution index rose sharply for three consecutive days, which made many Fuzhou citizens feel breathless. The general trend of sandstorm weather days in northern China is close to normal or less, and it is unlikely that there will be an abnormal increase. This is the conclusion issued by the relevant departments after comprehensive analysis of precipitation, vegetation and other aspects yesterday. According to the Straits Metropolis Daily published here today, Yu Hua, an engineer of Fuzhou Environmental Monitoring Center, said that the proportion of light air pollution in Fuzhou will not exceed 5% in a year, and it mostly occurs in winter and spring. This happened a few days ago. According to preliminary analysis, 10 was affected by sandstorm weather in the north. The dust went south with the cold air and was transported to Fujian Province. At the same time, the meteorological conditions in Fuzhou at that time were not conducive to the diffusion of pollutants, which increased the concentration of inhalable particles in the air. The analysis of the weakening trend of sandstorm shows that the precipitation in northern China in 2002 was slightly higher than that in previous years, and the drought for many years was alleviated. According to the comprehensive analysis of atmospheric, oceanic and weather climate signals, it can be predicted that in the spring of 2003, there will be more precipitation in China, and the cold air force will be weak, and the dust weather may be close to normal or less. Experts believe that in recent years, China has successively implemented key forestry construction projects such as returning farmland to forests, protecting natural forests and preventing and controlling desertification. Many provinces and regions in the north have successively implemented measures such as banning grazing, firewood and reclamation, which have effectively restored and protected vegetation. According to statistics, in 2002, the vegetation coverage in northern China increased by 5%- 15% compared with 200 1 year. The implementation of key forestry projects and the improvement of forest and grass vegetation have played a good role in increasing rainfall, increasing air humidity and restraining sandstorm weather. Although the dusty weather may decrease this year, experts still remind everyone to be alert to the impact of strong dusty weather on society and the fact that there are more dusty weather in some areas. 3 The control of sandstorms is mainly composed of three factors: first, the conditions for strong winds; Second, the factors causing strong vertical instability in the lower troposphere; Third, there are abundant dust sources in the local geographical environment. There are two major sandstorm-prone areas in China: the first is in the northwest, mainly concentrated in three areas, namely, the surrounding area of Tarim Basin, Turpan-Hami Basin passing through Hexi Corridor, Ningxia Plain to northern Shaanxi, Alashan Plateau in Inner Mongolia, Hetao Plain and Ordos Plateau; The second frequent area is in North China, which directly affects the security of the capital Beijing. The sandstorm in China is getting more and more serious, which is mainly caused by unreasonable land development and unreasonable farming. With the increase of population and inadequate management, a large amount of land in northwest and north China has been reclaimed, grasslands have been overgrazed, and natural vegetation has been destroyed artificially, resulting in a large number of bare and loose land, which provides a large number of dust sources for the occurrence of sandstorms. Once a strong wind occurs, it will affect society and endanger people's health. Suspended particles in sandstorms mainly come from farmland. It is our understanding of objective laws to focus on preventing and controlling sandstorms in farmland and degraded grasslands. Sandstorm is the result of unreasonable exploitation of land by human beings, which provides a rich source of dust for strong winds and leads to serious wind erosion. The traditional farming methods in our country have great disadvantages, such as plowing and raking the soil for many times, resulting in loose farming layer, which is the root cause of serious soil erosion and wind erosion. We should start with the reform of farming system and completely deny the traditional farming methods. Vigorously promote the no-tillage method and shoulder the historical responsibility of controlling sandstorms. At present, there is a misunderstanding in sandstorm control in China, which holds that defending sandstorm is desert control. It is considered that sandstorm is a harm to human beings caused by sand grains in the desert, but it is not recognized that the main harmful components of sandstorm are fine particles with a diameter less than 100 micron, which mainly come from farmland and degraded grassland. Second, it is considered that sand control is afforestation. The construction of the National Three-North Shelterbelt and the sand control projects around Beijing, Tianjin and Hebei all attach importance to afforestation. Two misunderstandings lead to the prevention of sandstorms. Forest belts are just a measure to prevent sandstorms, that is, to set up a wind barrier. The most important measure to prevent sandstorm is ground covering. The main sandstorm areas are mostly in arid and semi-arid areas, not forest areas, and the afforestation effect is generally not good: the survival rate of trees is low and their growth is poor, and most of them are "small old trees". The State Environmental Protection Administration recently held a news briefing, and relevant departments informed news organizations of their research results on the impact of sandstorms and yellow sand on atmospheric particulate matter in Beijing. The State Environmental Protection Administration decided to continue to carry out ecological protection research in order to formulate effective countermeasures to prevent and control sandstorms. According to reports, the State Environmental Protection Administration organized experts from the China-Japan Friendship Environmental Protection Center and relevant units to carry out a "study on the impact of sandstorms and yellow sand on atmospheric particulate matter in Beijing". On the basis of many years' research on the occurrence, transmission and settlement of sandstorm and yellow sand aerosol, the ground dust monitoring network system of relevant measuring points in Inner Mongolia, Hebei, Shaanxi, Beijing, Xinjiang, Shanxi and other provinces, autonomous regions and municipalities directly under the central government was established by using high and new technologies such as remote sensing and laser radar. Relevant experts pay attention to three objectives, namely, the origin and propagation path of sandstorms; Influence of sandstorm on atmospheric particulate matter in Beijing: countermeasures to slow down the influence of sandstorm on Beijing area. The research results preliminarily confirmed the source of sandstorm and its influence on atmospheric particles in Beijing. Relevant experts from the State Environmental Protection Administration put forward countermeasures and suggestions for prevention and control. The results show that there are both overseas and domestic sources of sandstorms that affect China every winter and spring. The overseas source areas mainly include Gobi desert in southeastern Mongolia and desert in eastern Kazakhstan; The source areas in the territory mainly include the Su Nite Basin in eastern Inner Mongolia, the central and western parts of Hunshandake Sandy Land, the border area between China and Mongolia in Alashan League, Taklimakan in southern Xinjiang and kurban Tong Desert in northern Xinjiang. Experts put forward countermeasures and suggestions for prevention and control: 1. Establish an ecological barrier based on greening in the surrounding areas of Beijing and Tianjin in the north of Beijing; Second, in the central and western regions of Hunshandake, Inner Mongolia, promote the ecological restoration and protection belt with returning farmland to forests and grasslands as the core; 3. In the Hetao area and yellow sandy soil area, focus on protecting water resources and natural oases, controlling desertified land, preserving natural oases and gradually expanding artificial forests; 4. The desert area in southern Mongolia is the main sandstorm source area that will affect China for a long time now and even in the future. Therefore, we should establish a long-term cooperation plan framework with Mongolia to prevent and control sandstorms as soon as possible. 200 1 year, funded by the Ministry of Agriculture, China Agricultural University conducted a 1 100 mu no-tillage experiment in Nangang Village, Yuershan Town, Fengning Manchu Autonomous County, Hebei Province, and the effect was remarkable. Through the experiment, we not only saw the positive effect of no-tillage management, but also found that no-tillage planting has great benefits in increasing production and saving costs. It is embodied in the following three aspects: (1) reducing the cost of breeding. No-tillage sowing saves three links of traditional tillage, such as ploughing, harrowing and soil preparation, and saves18-20 yuan per mu. (2) Preserve moisture and store water to strengthen seedlings. No-tillage sowing has less soil turnover, which is beneficial to soil moisture conservation. No-tillage sowing is 7- 15 days earlier than traditional sowing, and the whole seedling is strong. (3) Increase wheat yield. The yield of no-tillage wheat is 45.48% higher than that of traditional tillage. When bare, loose and dry land is exposed to windy weather, wind erosion and dust will occur. This is caused by traditional farming, overgrazing and vegetation destruction. In wind erosion, coarse particles move within the range of 1-2 meters from the soil surface. However, many fine particles are suspended in the wind and move hundreds of kilometers with the wind, forming a large dust mass, causing air quality problems. Suspended particles do great harm to air and soil quality. Dust reduces visibility, pollutes air, damages property and harms people's physical and mental health. These fine particles are the most fertile part of the soil, and the content of organic matter and nitrogen is twice that of the original soil. Reducing and controlling wind erosion in farmland is mainly to protect farmland by using growing crops and crop residues. There are two principles to prevent sandstorms. First, reduce the wind directly acting on soil particles; The second is to improve the surface condition of soil, improve the ability of soil to resist wind erosion or limit the movement of soil particles. Therefore, the main measure to prevent and control sandstorms is to popularize no-tillage method. No-tillage is a farming system that minimizes soil tillage and leaves crops on the surface. It is an improved intensive cultivation method, which can prevent water erosion and wind erosion. No-tillage agricultural system cancels many traditional agricultural operations, such as ploughing, harrowing and land preparation. Crop residue mulching can effectively reduce the dust particle movement caused by strong wind, absorb some wind and reduce the force of wind on soil. Xinhuanet Hohhot 1 28th (Reporter Shi Guiping) At the beginning of the new year, Hulunbeier City, Inner Mongolia Autonomous Region launched a "Pinus sylvestris var. sylvestris var. sylvestris var. sylvestris Action" and plans to establish a "Pinus sylvestris var. sylvestris var. sylvestris". "Mongolian Green Corridor" in Hulunbeier Sandy Grassland. Pinus sylvestris var. mongolica. Pinus sylvestris var. mongolica is a native tree species in Hulunbeier city, which has the characteristics of cold tolerance, drought tolerance, light preference and strong adaptability. Sandy grassland is especially suitable for the growth of Pinus sylvestris var.mongolica.. Mongolian kapok. There are various forms of Pinus sylvestris var. mongolica in a large area. Quercus mongolica grows on the sandy land of suburban park in Hailaer District, Hulunbeier City, and it is still flourishing after more than a hundred years. Hulunbeier grassland used to be the best grassland with abundant water and grass in China. There was a large area of Pinus sylvestris var. mongolica forest in history. The Mongolian oak forest in Hulunbeier grassland has formed a natural grassland protection barrier. In recent decades, due to man-made and natural reasons, desertification is devouring grasslands. At present, the sandy land area of Hulunbeier grassland has reached nearly 880,000 hectares, accounting for 12.69% of the whole grassland area. The phenomenon of desertification has attracted great attention from the forestry department. In order to control desertification and restore vegetation, Pinus sylvestris var. The "Mongolia Action" project formulated by Hulunbeier Forestry Bureau is constructed in three phases: the first phase, from 2003 to 2007, includes two construction areas and a management protection area with a total area of/kloc-0.59 million hectares; The second stage is from 2008 to 20 10, and its scope is mainly to build the management protection zone in the first stage; The third stage is from 20 10 to 2020, with a total area of1190,000 hectares. After the completion of the project, the forest ecosystem of Pinus sylvestris var. mongolica. Mongolia Green Corridor will be formed, with a length of 250km from north to south and a width of140km from east to west. The cause of sandstorm land desertification is a geological event in the process of earth evolution, and it is a special geological phenomenon that lithosphere and atmosphere, biosphere and hydrosphere strongly act on the crust surface; Sandstorm directly related to desertification is the result of comprehensive factors, which may occur in human history or geological history, in which natural action is the dominant factor, and human activities are only local factors to accelerate or slow down the occurrence of sandstorms. This is the latest conclusion reached by the research group of "Dynamic Simulation and Evaluation of Land Cover Change in Capital Economic Circle" of China Geo University. This project, which is included in the "Free Exploration Project" of the Ministry of Land and Resources, creatively integrates many disciplines such as geology, remote sensing, geography, meteorology, hydrology, ecological environment, social humanities and geographic information system, and uses quantitative analysis methods to explore the evolution mechanism and recent development trend of land desertification, and puts forward suggestions for prevention and control. Using the most advanced cellular automatic inference engine technology in the world, the research team designed a land desertification simulation system. As long as you input the future year you want to study in the computer, the computer can directly draw the desertification demonstration map of the input year. The simulation results show that the evolution of desertification will not affect Beijing's hosting of the 2008 Olympic Games. The prediction that China will move its capital for natural reasons in the next 50 years is completely wrong, and Beijing will not become the second "Loulan Ancient City" in China within 200 years. Chen Jianping, the head of the research group and doctoral supervisor of the School of Earth Sciences and Resources, University of Geosciences, said that the research group investigated a number of factors that may be related to desertification and sandstorms, such as population density, total economic income, population education level and grazing situation, and found that human factors played a secondary role in the formation of sandstorms. In recent years, overgrazing in some areas has played a certain role, but natural factors have played a leading role.