CALINE4模型扩散参数的城市建筑影响

Influence of buildings on diffusion parameters in CALINE4 model

机动车尾气排放已经成为城市空气污染的主要原因之一,为了更好地了解机动车尾气扩散,在GIS领域为机动车尾气的治理提供帮助,该文基于CALINE4模型对城市道路中机动车尾气的扩散特性进行研究。通过ENVI-met软件模拟验证了建筑物对污染气体扩散的显著影响,在CALINE4模型的基础上综合考虑了道路两侧建筑物对机动车尾气的反射作用和阻塞作用,结合道路的街谷高宽比和阻塞比的概念,提出了一种在建筑物影响下CALINE4模型中扩散参数的修正方案,并定性分析了建筑物对模型中扩散参数的影响以及对机动车尾气扩散过程的影响。分析结果表明,建筑物对机动车尾气的扩散有明显的反射与阻塞作用,尤其在建筑密集的区域会产生二者的叠加,使该区域污染物浓度分析更加复杂。

Vehicle exhaust has become one of the main causes of air pollution in cities.In order to better understand the diffusion of vehicle exhaust and provide help for the control of vehicle exhaust in the GIS field,the diffusion characteristics of vehicle exhaust in urban roads were studied in this paper,on the basis of california line source dispersion model 4(CALINE4)model.The ENVI-met software was used to verify the significant influence of buildings on the diffusion of polluted gases.With the reflection and blocking effects of the buildings on vehicle exhaust taken into account,a modified scheme for diffusion parameters in the CALINE4 model under the influence of buildings was proposed,combined with the concept of height-width ratio of the street valley and volume blocking ratio.Then,the influence of buildings on diffusion parameters in the model and the influence on vehicle exhaust diffusion process were qualitatively analyzed.The analysis results showed that buildings had obvious reflection and blocking effect on the diffusion of vehicle exhaust,especially in the area of dense buildings,the superposition of the two made the analysis of the pollutant concentration more complex.