Street is an important place for urban residents, and the air quality in streets is closely related to residents' health. Air pollutant diffusion model is an often used measure to simulate and evaluate air quality in street canyon in recent years, but the problems existing in model application need to be clarified. This review selected four air pollutant diffusion models, i.e., ENVI-met, FLUENT, MISKAM and OSPM, which were most popular in street canyon studies. Through comparisons on the model mechanisms, the operational processes, the temporal-spatial resolutions and so on, their differences in model scopes and modeling capabilities in street canyon air quality simulation were discriminated, the model deficiencies were pointed out according to temporal scale, modeling, weather handling, turbulent simulation and photochemical pollution, and several model optimization measures were suggested in terms of street canyon study. Moreover, through reviewing the case stu-dies of the four models, the shortcomings in model application were concluded, and some new techniques were highlighted for future application studies such as laser radar to improve input data accuracy, and the importance of considering urban heat island and urban pollutant island simultaneously was emphasized in evaluating street environment quality.
城市街道是城市居民的活动场所,其空气质量与居民健康密切相关.空气污染扩散模型是模拟和评估街道空气质量的重要方法,近年来广受关注,但模型应用存在问题,亟待解决.本文介绍了4种常用的空气污染物扩散模型:ENVI-met、FLUENT、MISKAM和OSPM.通过工作原理、运算流程、时空分辨率等的对比分析,明确了各模型的适用范围及其对街道峡谷内空气质量模拟能力的差异,阐述了各模型在时间尺度、物理建模、天气模拟、湍流模拟及光化学污染方面处理能力的局限性,提出了模型优化途径.通过综合分析4种模型的研究案例,总结了模型应用中存在的问题,提出未来研究可以通过激光雷达等新技术提高模型参数的获得精度,并强调综合模拟污染效应与热效应等对评估城市街道空气质量的重要性.
Keywords: air quality; development trend; diffusion simulation; street canyons.