For the rarely researches that the atmospheric environment effects of Southwest Vortex(SWV), routinely observed meteorological data, air pollution monitoring data, atmospheric sounding data and Climate Forecast System Version 2 (CFSv2) products have been used to counted the number of SWV in winter and spring 2014 -2016 and the synchronous air quality grade with diagnostic and statistical methods in this study.It is found that SWVs developed in spring and winter are mostly dry low vortices due to the lack of water vapor.This type of SWV rarely induces precipitation and can easily cause air pollution weather in the Sichuan Basin.Based on those results, a dry and a wet SWV in Sichuan Basin in 2015 were selected for comparative study.The analysis of a severe air pollution over the Sichuan Basin from 29 December 2015 to 3 January 2016 suggests that a dry SWV was generated over Sichuan Basin on 30 December with weak intensity and small thickness.The foehn effect arising from the weak descending motion at the rear of dry SWV caused an intensive untouched?ground low?level inversion over Chengdu, generated a ‘pot cover’ effect that suppressed the diffusion of air pollutants, brought about an quite small maximum mixing depth and surface wind speed which presented an obvious stagnate synoptic status, gave rise to the concentrations of PM₁₀ and PM_2.5 of representative cities in basin were 398 and 268 μg·m^-3, respectively, which were the peak values during this heavy air pollution process.In contrast, the study found that, during August 16 -17, 2015, the strong upward movement and heavy precipitation resulted from the wet SWV produced the extremely favorable effects of atmospheric diffusion and wet deposition, rapidly and effectively reduced the concentration of pollutants, which was opposed to the environmental effect of the dry SWV that aggravating atmospheric pollution.

Based on wind, cloud and precipitation data of 79 meteorological stations over the Hebei province, the atmospheric environmental capacity (AEC) was calculated by applying A value method, climate change characteristics and trends of AEC were analyzed. The time points of abrupt change for AEC was tested by Mann-Kendall and Moving-T technique. Based on EOF analysis, the temporal and spatial variation features of AEC were studied. Results show that the climatic value of seasonal spatial distribution characteristics of AEC is relatively consistent, northwest of Zhangjiakou and Chengde area is significantly greater than the other parts, and Hebei Piedmont is lower than the surrounding, climatic value of AEC changed from high to low throughout the year. From 1972 to 2013, the annual and seasonal AEC have been observably decreasing in most part of Hebei and the abrupt change point is spring in 1983, summer and autumn both in 1998, winter in 1988. The first 2 eigenvector of EOF reflect the most characteristics of annual and seasonal spatio-temporal distribution of AEC from 1972 to 2013, the first eigenvector of contribution rate is more than 43%, reflects holistic characteristics in the whole province, the corresponding time coefficient indicates that there is an interdecadal weakening trend of AEC.

In responese to the planning office's demands to analyze and evaluate different layouts,based on an urban sub-domain scale meteorology and pollutant diffusion model,a set of index system and evaluating scheme of impact assessment of urban sub-domain planning on meteorology and atmospheric environment is set up.As an example,two layouts of a sub-domain in Beijing are assessed.It shows that,because there is a wide road with grass and trees in east-west direction in the second planning,the road becomes an important channel for airflow.And the wind speed around the road is bigger,air temperature is lower,pollution is weightless,so the strip domain around road is good to the improvement of meteorology and atmospheric environment in the whole sub-domain.In a word,it is available and necessary to evaluate the impact of urban sub-domain planning on meteorology and atmospheric environment. The six assessment indexes(body comfortable degree,walker comfortable degree, ground pollutant concentration,pollutant concentration below the highest building,pollutant concentration on the surface of buildings and diffusion capability) and their weighted factor 0.2,0.1,0.1,0.1,0.1 and 0.4,respectively are firstly pointed out,finally the impact of urban sub-domain planning is evaluated by taking the weighted everaging.and the evaluating method of weighted average is reasonable and practical.

With monitoring data from 1996 to 2001,analyzing the annual mass concentration change of SO₂,NO_X and TSP that is harmful to Dunhuang frescos,we draw some conclusions as follows.Aver age mass concentration of SO₂,NO_X in the air is 0.0268 mg·m^-3 and 0.0217 mg·m^-3,respectively,satisfying national second standard criteriain GB3095-1996.But the mass concentration of TSP is 0.3077 mg·m^-3 and 153.9% of that of national second standard criteria.The mass concentrationof SO₂ appears a conspicuous rising trend and should pay more attention.We suggest that it should strengthen ecological environment construction in grotto region and link with protection of whole Dunhuang oasis.A good condition for frescos preservation can be created by the means of controlling tourists reasonablyto reduce the content of harmful components.

Through numerical simulation method, the atmospheric capacities of sulfur dioxide in Lanzhou winter have been studied to offer the premise and basis for the total quantity control method, which is usualy one of the atmospheric pollution control methods.First, the concentration of sulfur dioxide in Lanzhou city are simulated with the Hybrid Particle and Concentration Transport Package Model(HYPACT), which is forced the meteorological conditions produced by a three-dimension model, the Regional Atmospheric Modeling System Version 4.3(RAMS4.3).Then, concentration-shared ratio of each pollution unit in Lanzhou is computed.Finally, using the linear programming method, the atmospheric capacities of SO₂ of representative days in Lanzhou winter are calculated according to the atmospheric state quality standard.

The concentrations of pollutant gases (including SO₂,O₃ and NO_X) and aerosol at the ground surface were measured in Xiaozhangzhuang eco-village area during Oc-tober 1997,May 1995 and April 1997. The results obtained from measurements and analyses display some average characteristics, time-variation and season-variation of pollutant gases. It shows that the atmospheric environment over Xiaozhangzhuang area is clear during the measurements. The results show that the photochemical reaction controlled by overall solar radiation is the determining factors affecting the variation of the surface O₃. Fine aerosol is over 99% of the total amount. Its daily variation is strongly influenced by convection and turbulent diffusive transfer and its concentration spectrum displays single-peak and single-val-ley. There are obvious correlation between aerosol concentration and air humidity.

In this paper,the physical mechanism and objective cause of formation of atmospheric pollution over Lanzhou city are analysed. And the methods and measures which are being adopted or demonstrated for controlling atmospheric pollution at present are summarized,analysed and discussed. Then,the several problems which need studing as focal point are pointed out. Finally,the preliminary views and proposals about controlling atmospheric pollution of Lanzhou city are suggested.