Air Pollution Concentration Approach to Potential Area Selection of the Air Quality Monitoring Station in Nakhon Ratchasima Municipality, Thailand

The purpose of the study is to generate traffic air information system） to determine a proper zone of AQMS （air analyzed were carbon monoxide （CO）, and nitrogen oxides （NOx） pollution map using mathematical model and GIS （geographic quality monitoring station） in municipality area. The pollutants which can be harmful to people living in the area. The three steps of mapping process were performed under the GIS environment using the existing vehicle emission rates and pollutant dispersion model. First, traffic volume, road network, and the emission rates of road segments varying with types of vehicle were collected from existing data. Second, the pollutant concentrations were calculated by use of CALINE4, a tool with Gaussian dispersion model. The model parameters include emission rate, wind directions and speeds, ambient temperature and observed pollutant concentration, and atmospheric stability during all seasons from the January 1, 2010 to May 31,2011 with regardless the rainy season. This resulted in concentrations at many receptor points along links of the road network. Third, distributions of pollution concentrations were generated by means of the spatial interpolation of those from receptors. The results of pollution raster-based maps are used for determining frequency of violence and combined pollution map. The resulting frequency of violence and intensity concentration will be further integrated to determine a potential area of AQMS. Finally, achieving pollution potential area of AQMS can be located as helpful basic data for efficient traffic and transportation planning.

基于3DGIS的机动车尾气扩散模拟和体视化研究

在城市中,空气污染物的主要来源是机动车尾气,探求城市机动车尾气扩散规律并积极寻求改善措施已成为许多城市迫在眉睫的问题。目前对机动车尾气扩散模拟的研究较多,但对扩散过程建模和体视化分析的研究较少。为此,提出了一个基于3DGIS的机动车尾气扩散建模和可视化框架。首先,在3DGIS中完全整合CALINE4(California line source dispersion model-4)模型,用连续场模型表达动态扩散过程,在语义空间建立统一数据模型表示建筑、道路、树木以及动态扩散过程数据;其次,采用基于GPU(graphics processing unit)的直接体绘制方法对过程数据进行可视化分析,重点优化梯度计算、体纹理重采样和动态插值等关键算法,动态表达机动车尾气的扩散过程;最后,通过北京地区一条典型的道路机动车尾气扩散实验,检验了该方法的可靠性和高效性。

城市机动车尾气扩散过程三维动态可视化研究

为研究城市机动车尾气扩散规律并寻求空气质量的改善措施,该文提出一种针对机动车尾气扩散过程的三维动态可视化表达方法。研究了CALINE4模型,顾及了道路特征和风向;模拟城市道路机动车尾气扩散过程,生成时间序列的体过程数据,从而得到CO、NOx等机动车污染气体的扩散及分布情况;利用光线投射算法进行直接体绘制。该方法能够有效模拟机动车尾气的扩散情况,并实现三维动态可视化。最后通过实验模拟一条道路的机动车尾气扩散情况,对道路机动车尾气扩散可视化结果进行分析,验证本文选取方法的有效性和可行性。