Study Of The Diffusion Conditions Of Atmospheric Pollutants And Atmospheric Environment Capacity In Yulin City Based On MM5and CALPUFF Models

Yulin is a big city of energy development and utilization in our country, wherethere is a coal-dominant energy consumption structure for a long time, which willresult in a serious environmental pollution. It is of significance for the governmentdepartments and regulatory agencies to analysis the capacity of atmospheric diffusionin the round, and measure capacity of atmospheric environment in Yulin City, whichis beneficial to develop environmental policy scientifically and layout industrial parksreasonably.In this study, on the basis of understanding objectively of atmosphericenvironment quality at present, the mesoscale meteorological model (MM5) and airquality dispersion model (CALPUFF) were used to simulate the concentrations ofSO2, NO2and PM10in Yulin City in2012. The effect factors on atmosphericdiffusivity in Yulin were analyzed, such as terrain, weather and pollution situation.The atmospheric environment capacities in Yulin were calculated used A-valuemethod and multisource model simulation. The results indicate as follows:(1)A-value method and the simulation method were employed to research theatmospheric environmental capacities. The final result showed that the capacities ofSO2, NO2and PM10in Yulin City were13.35×104t/a，15.93×104t/a and10.88×104t/a,respectively.(2)According to topography and meteorological characteristics in Yulin City, Theenvironmental status was analyzed based on, The atmospheric environmental bearingcapacity in the region of Shenmu and Fugu have exceeded its carrying capacity underthe circumstances of existed emission sources load, so much so that some emissionsshould to be reduced.(3) From the whole city to consider, along with the area of river valley, where thealtitude is lower, the conditions of terrain and weather are not conducive to diffuse foratmospheric pollutants, and the atmospheric environment of capacity is small. What’smore, there is the more densely populated part of the city and the emission quantity ofexhaust gas is large. Consequently, enterprises with large emission should be excluded in this region in industrial layout planning. However, the surroundings of Dingbianand Jingbian County, where the elevation is higher, is better to atmospheric dispersion,and the existed emission sources are small. Thus, the industrial distribution should befocused on this region in the future.