Study on the Layout of Urban Planning in Rapid Urbanization Areas under the Background of Air Pollution

China＇s urbanization has been over the medium-term process,which has made great achievements,but also triggered a huge problem of air pollution. Air pollution has become a big problem after the water pollution in China,and a serious threat to people＇s life and health. Under the background of ＂ the construction of beautiful China＂ and rapid urbanization,how to build a beautiful home has become the focus of attention. Taking Shenyang as an example,the author contrastively analyses the spatial distribution of the main air pollutants（ PM10,PM2. 5,and SO2） and the present situation of land use,and thus finds out the rules between pollutants distribution and land use. Then combining the urban planning scheme and the rules obtained above,reasonable suggestions are proposed for the scheme to improve the air quality,and reduce or avoid air pollution,and providing the basis for the construction of a piece of blue sky. The conclusions are as follows： 1 air pollutants concentration above Light Oil Gas Making Factory in south vice city of Shenyang reaches the peak value,and industrial point source is the main air pollutants emission source; 2 pollutants concentration above greenbelt is the lowest; 3 the overall spatial structure of urban planning can insulate the industrial agglomeration areas to some extent; greenbelt planning covers 40%- 50% of the area with high concentration of air pollutants,and it is suggested to achieve full coverage; traffic planning can achieve shunt most of the pollutants in many regions,but it can also expand the scope of pollutants in some certain regions,in such regions,it should reduce the road density.

Pollutant concentrations and pollution loads in stormwater runoff from different land uses in Chongqing

To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing,six typical land use types were selected and studied from August 2009 to September 2011.Statistical analysis on the distribution of pollutant concentrations in all water samples shows that pollutant concentrations fluctuate greatly in rainfall-runoff,and the concentrations of the same pollutant also vary greatly in different rainfall events.In addition,it indicates that the event mean concentrations （EMCs） of total suspended solids （TSS） and chemical oxygen demand （COD） from urban traffic roads （UTR） are significantly higher than those from residential roads （RR）,commercial areas （CA）,concrete roofs （CR）,tile roofs （TRoof）,and campus catchment areas （CCA）;and the EMCs of total phosphorus （TP） and NH3-N from UTR and CA are 2.35-5 and 3 times of the class-III standard values specified in the Environmental Quality Standards for Surface Water （GB 3838-2002）.The EMCs of Fe,Pb and Cd are also much higher than the class-III standard values.The analysis of pollution load producing coefficients （PLPC） reveals that the main pollution source of TSS,COD and TP is UTR.The analysis of correlations between rainfall factors and EMCs/PLPC indicates that rainfall duration is correlated with EMCs/PLPC of TSS for TRoof and TP for UTR,while rainfall intensity is correlated with EMCs/PLPC of TP for both CR and CCA.The results of this study provide a reference for better management of non-point source pollution in urban regions.

Numerical study of the effects of local atmospheric circulations on a pollution event over Beijing–Tianjin–Hebei, China

Currently, the Chinese central government is considering plans to build a trilateral economic sphere in the Bohai Bay area, including Beijing, Tianjin and Hebei（BTH）, where haze pollution frequently occurs. To achieve sustainable development, it is necessary to understand the physical mechanism of the haze pollution there. Therefore, the pollutant transport mechanisms of a haze event over the BTH region from 23 to 24 September 2011 were studied using the Weather Research and Forecasting model and the FLEXible-PARTicle dispersion model to understand the effects of the local atmospheric circulations and atmospheric boundary layer structure. Results suggested that the penetration by sea-breeze could strengthen the vertical dispersion by lifting up the planetary boundary layer height（PBLH） and carry the local pollutants to the downstream areas; in the early night, two elevated pollution layers（EPLs） may be generated over the mountain areas： the pollutants in the upper EPL at the altitude of 2–2.5 km were favored to disperse by long-range transport, while the lower EPL at the altitude of 1 km may serve as a reservoir, and the pollutants there could be transported downward and contribute to the surface air pollution.The intensity of the sea–land and mountain–valley breeze circulations played an important role in the vertical transport and distribution of pollutants. It was also found that the diurnal evolution of the PBLH is important for the vertical dispersion of the pollutants,which is strongly affected by the local atmospheric circulations and the distribution of urban areas.