Spatial Scale Effect Of Atmospheric Environmental Impact Assessment For Regional Planning

In recent years, the importance and urgency of Strategic Environmental Impact Assessment (SEA) has been gradually recognized in China. As a SEA at planning level, the Plan Environmental Impact Assessment (Plan Environmental Impact Assessment, PEIA) in boomingin China. However, the theory and methodology of PEIAis still under development. The regional PEIA is the particular case, whoseresearch theory and methodologyhas not been formed completely. The methods used on regional PEIA are all kinds without argument.For the sake of the development of economy and society, the regional PEIA starts to focus on the involved Society-Economy-Environment system, in which the area and spacialcharacteristics have been enhanced. However, whether from domestic or international, scale issues (with prominent spacialcharacteristics) in the evaluation of PEIA are long-term neglected important issues. The scale issues in regional PEIA involve the problems, which the PEIA should answer and solve. It is the core issue of PEIA. Therefore, exploring the effect of the scale issues in the regional PEIA research is conducive to China’s regional PEIA practice, and helpful to scientifically define the scope of PEIA and the research content of PEIA.Baoshan District in Shanghai has been taken as the study case.From the view of the atmospheric environmental impact assessment of regional planning, the research on spatial scale effect was carried on. In the process of research, four schemes have been designed in the consideration of the research on emission inventorys of different space scope and different degree refinement.Through the comparison analysis between the two schemes, results have been concluded, to achieve the study.This paperuses WRF meteorological model combined with CALPUFF atmospheric model. Firstly, the credibility of the model was verified based on the three kinds of pollutants, NOX, CO, PM10dispersion simulation of the three time periods under four kinds of schemes. And then the dispersion simulation has been taken on the four schemes from different space scope and different degree refinement of emission inventory.Several important conclusions are as follows:1. Under heavy pollution weather, small scope simulation concentration’s relatively high value area is different from that of large scopesimulation, which looks as a whole area. In the diagram, the former is more likely toshow the its"heterogeneity".2. Better the air quality are, using the same emission inventory, daily average concentration’s spatial distribution of large scopesimulation are more similar to that of small scope simulation.3. Whenuse high degree refinement of emission inventory, the differences between the simulation concentration’sspatial distributionin small scope and large scope, is greater than that under the use of lowdegree refinement of emissioninventory.4. Better the air quality are, in the same scope simulation, daily average concentration’s spatial distribution,using lowdegree refinement of emission inventory are more similar to that using highdegree one.5.In the small scope simulation, the differences between the simulation concentration’sspatial distribution, using different degreerefinement of emission inventoryis greater than that using the highdegree one.