基于全景图的城市街谷平均辐射温度计算模型研究  

Investigation on the predictive model of mean radiant temperature in urban street canyons with panorama images

作　　者：杨柳[1] 张腾跃 刘衍 李奇 雷宸骁 YANG Liu;ZHANG Tengyue;LIU Yan;LI Qi;LEI Chenxiao

机构地区：[1]西安建筑科技大学建筑学院 [2]华南理工大学建筑学院

出　　处：《西部人居环境学刊》2024年第2期151-157,共7页Journal of Human Settlements in West China

基　　金：国家自然科学基金面上项目(5207840)。

摘　　要：在评估城市街谷热环境对居民生活质量的影响时,明确街谷的微气候条件,尤其是平均辐射温度(Mean Radiant Temperature,MRT)对于改善城市热环境具有重要意义。现阶段,利用基于鱼眼图的天空视域因子(Sky View Factor,SVF)计算方法较为繁琐且难以实现大范围街谷MRT的时空分布评估。因此,本研究旨在通过全景图像技术,提出一种快速大量计算城市街谷MRT时空分布的新方法,并进一步考虑城市街谷中树木的影响,以改进传统模型。本研究首先基于全景图像批量获取城市街谷中的SVF,并结合城市街谷中的几何特征和植被视域因子,通过改进的平均辐射温度计算模型对单点的MRT进行计算,同时采用定点实测数据对该模型进行精确度验证,并将其应用于西安市街谷MRT的实际计算中。研究结果显示,经过模型验证,本研究方法具有较高的精度,相对误差大多数情况下在20%以内,RMSE在2.85~4.66℃。同时,模型与实测数据的一致性较好,能够清晰地反映MRT的变化趋势,R2大于0.74,IA大于0.80。与仅考虑单一不透水面的计算模型相比,考虑树木植被后的模型精度有明显提升,RMSE从5.15℃降至3.87℃,模型的R2由0.72提升至0.74,表明改进模型与观测结果具有更好的一致性。提出的基于全景图的MRT计算方法不仅提高了评估城市街谷热环境的效率和精度,而且通过考虑树木植被的影响,为城市规划和绿化管理提供了更加科学的指导。此外,本研究的方法和结论能够为城市热岛效应的缓解和城市生活环境的改善提供理论依据和技术支持。通过实例分析,研究成功地应用于西安市,展示了2021年7月14日上午9:00的街谷MRT分布图,为后续的城市热环境评估和改善工作奠定了基础。Urbanization has profoundly transformed natural landscapes into man-made environments,notably converting natural vegetation cover into impervious surfaces.This transition significantly impacts the near-surface energy balance and material exchange,leading to the formation of distinct urban climates.The design and layout of urban areas have a substantial influence on local microclimates,which in turn affects the thermal comfort of residents in those regions.The relationship between urban form and thermal comfort is complex and multifaceted.Urban street canyons,as fundamental components of urban morphology,significantly impact both indoor and outdoor microclimates,human thermal comfort,and energy consumption in buildings.Understanding this relationship is crucial for designing and planning sustainable and livable cities.Previous research has often been limited by the scale of urban data samples,typically focusing on concentrated areas such as neighborhoods and parks,with less attention paid to urban street canyons.This study aims to explore the distribution patterns of thermal comfort within urban street canyons,building on existing models for predicting Mean Radiant Temperature(MRT)and leveraging large-scale data acquisition and computational methods.The validation and optimization of the predictive model were conducted in the Xi’an area.When evaluating the effects of urban street canyon thermal environments on the quality of life for city residents,it is essential to accurately assess the microclimatic conditions within these canyons.Of particular importance is the Mean Radiant Temperature(MRT),a critical factor that significantly influences the thermal comfort of urban environments.Traditional methods,such as those employing fisheye lens photographs to calculate the Sky View Factor(SVF),are both labor-intensive and impractical for large-scale assessments of MRT’s spatial and temporal distribution within urban street canyons.This paper introduces a novel approach that utilizes panoramic imaging technology to r

关 键 词：平均辐射温度 全景图 城市街谷 视域因子 实地观测 

分 类 号：TU111[建筑科学—建筑理论]