Study On The Impact Factors And Applications Of Dust Emission In Semi-arid Farmland Areas

Semi-arid areas of farmland caused by urban surface dust emission is an important source of particulate pollution is one. Looking at the current field of surface dust emission on the research content, research found that more decentralized, on farmland on the environmental impact of dust emission is still blank. In order to study the surface semi-arid farmland Dust Emission and harmful to the environment, this paper tests from the field observations, simulation studies and field surface dust emission associated with the analysis of urban particulate matter pollution to carry out a systematic study of three areas, the following three aspects Results:(1) Between 2008 and 2010, for different seasons in Xi'an, Tongchuan, Yan'an and Yulin four observation areas of farmland were exposed to field observations, observations that: Xi'an, Tongchuan, Yan'an and Yulin observed dust emission flux in the surface area of farmland Average summer were 6.8μg/m~2·s, 7.0μg/m~2·s, 15.4μg/m~2·s, 28.6μg/m~2·s, respectively, in winter 6.7μg/m~2·s, 11.2μg/m~2·s, 26.2μg/m~2·s, 45.1μg/m~2·s; daily average surface roughness are: Yulin observation area of approximately between 0.0026m≤Z0≤0.0191m; Yan'an observation area of approximately 0.0479m≤Z0≤0.0899m s Rooms; Tongchuan observation area of approximately between 0.0661m≤Z0≤0.1030m; Xi'an observation area of approximately 0.0627m≤Z0≤0.1319m between. Surface threshold friction velocity are: Yulin observation area is 0.0739m/s, Yan'an observation area 0.2601m/s, Tongchuan observation area 0.2837m/s and the observation area of Xi'an 0.2905m/s.(2)In the absence of vegetation cover, small changes in friction velocity, soil type, soil moisture, surface roughness and friction velocity and other observations of this study is the surface dust emission flux farmland main factors. By comparing field observations and computer simulations of draw, the four observations in this study area have good DPM model simulation accuracy.(3) By selecting a specific direction, field observations of suburban farmland bare surface dust emission flux, corresponding to the analysis and the relevance of urban air quality. The results showed that: Xi'an observed dust emission flux in the surface of farmland and urban areas the average visibility has some relevance; Xi'an observed dust emission of farmland and urban areas there is a certain correlation between PM10. Comparative analysis of Xi'an and gas particles in the air and farmland OCPs in surface soil mapping component contents OCPs and found that much of Xi'an OCPs in the air of dust released from the soil.