Abstract: High pollution levels often occurred in urban street canyon due to the increased traffic emissions and reduced natural ventilation. The main methods for studying the atmospheric environment in street canyons include field observations, reducedscale physical models and mathematical models. Field observations and physical models may be used to investigate pollutant transportation and dispersion within urban canyons and validate numerical models. On the other hand, validated numerical models are often applied to simulate in detail atmospheric dispersion within the urban canopy. The numerical results in combination with physical model and/or field data may be used to assess urban air quality and support decisionmaking for pollution control strategies and traffic planning. This article provides an overview of studying on atmospheric environment within street canyons in the latest decades.

Key words: atmospheric environment, street canyon, physical model, numerical model

摘要： 机动车尾气排放不断增加以及城市通风能力降低，常导致城市街谷内的空气污染。城市街谷大气环境主要研究方法包括外场观测、实验室物理模拟和数值计算。外场观测和物理模拟可以考察街谷内污染物的传输扩散规律并对数值模式进行检验，另外，复杂的数值模式则可对城市冠层内大气扩散问题进行详细模拟，数值模拟和外场观测及物理模拟相配合，可用于环境质量评价、污染控制决策及交通规划。重点介绍了近十年内城市街谷大气环境研究的主要成果。

关键词: 大气环境, 城市街谷, 物理模拟, 数值模式