聚焦树木特征及气象因素：城市街道峡谷风环境与污染物扩散的数值模拟剖析

Focusing on Tree Characteristics and Meteorological Factors: An Analysis of Numerical Simulations of Wind Environment and Pollutant Diffusion in Urban Street Canyons

摘要: 在全球城市化进程加速的背景下，城市热岛效应加剧、能源需求增长，同时室外空气质量下降成为城市面临的严峻挑战。城市绿色基础设施中的道路绿地对改善城市环境有重要意义，本研究聚焦于树木影响下城市街道峡谷内风环境与污染物扩散的问题。通过对道路及绿带类型进行系统归类，以实地监测和数值模拟为研究手段，详细分析相关研究中的污染物浓度指标、植物特征因子(如叶面积密度、植树布局、树冠形状等)及其他影响因子(气象因素等)。全面总结道路绿地对局地污染扩散的影响规律，发现现有研究存在树木特性描述不准确、模型参数复杂且需不断修正、多因素叠加效应研究不充分、叶片微观结构对污染物减少影响研究少等问题。基于此，明确未来研究应拓展研究对象，综合考虑多种生态过程，融合实地监测与数值模拟方法，提高数据的精度和丰富度，为优化城市街道峡谷树木种植、改善城市空气质量提供科学依据。

Abstract: With the acceleration of global urbanization, the urban heat island effect has intensified, energy demand has increased, and the decline in outdoor air quality has become a severe challenge for cities. Road green spaces in urban green infrastructure are of great significance for improving the urban environment. This study focuses on the issues of the wind environment and pollutant diffusion in urban street canyons under the influence of trees. By systematically categorizing the types of roads and green belts, and using on-site monitoring and numerical simulation as research methods, this study analyzes in detail the pollutant concentration indicators, plant characteristic factors (such as leaf area density, tree planting layout, crown shape, etc.) and other influencing factors (meteorological factors, etc.) in relevant research. The impact of road green spaces on local pollution diffusion is comprehensively summarized. It is found that existing studies have problems such as inaccurate description of tree characteristics, complex model parameters that need to be continuously corrected, insufficient research on the superposition effects of multiple factors, and few studies on the impact of leaf microstructures on pollutant reduction. Based on this, it is clear that future research should expand research objects, comprehensively consider multiple ecological processes, integrate on-site monitoring and numerical simulation methods, improve the accuracy and richness of data, so as to provide a scientific basis for optimizing tree planting in urban street canyons and improving urban air quality.