Urban Microclimate, Outdoor Thermal Comfort, and Socio-Economic Mapping: A Case Study of Philadelphia, PA
Urban Microclimate, Outdoor Thermal Comfort, and Socio-Economic Mapping: A Case Study of Philadelphia, PA
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DOI：
10.3390/buildings13041040
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发表时间：
2023-04
期刊：
影响因子：
3.8
通讯作者：
Farzad Hashemi;U. Poerschke;L. Iulo;G. Chi
中科院分区：
文献类型：
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作者：
Farzad Hashemi;U. Poerschke;L. Iulo;G. Chi
城市地区通常比农村地区温暖，这是由于所谓的“城市热岛”（UHI）效应，这可能会导致从事户外活动的人感到不适，并可能对低收入社区，有色人种和老年人产生不成比例的影响。城市热岛效应的强度受多种因素的影响，包括城市形态，这可能因地区而异。为了研究室外热舒适和城市形态之间的关系，在不同的城市街区与不同的社会脆弱性状态，本研究开发了一个基于地理信息系统（GIS）的工作流程，结合“当地气候带”（LCZ）分类系统和城市小气候评估工具，称为ECONO-MET。为了证明这种方法的有效性，该研究选择了两个不同的城市街区在费城，宾夕法尼亚州的高和低的社会脆弱性指数（SVI），比较他们的小气候条件与城市形态特征，如绿色覆盖面积，天空景观因子（SVF），街道高度与宽度（H/W）的比例。研究结果表明，在炎热季节和极热日，树木和草地覆盖度与室外空气和平均辐射温度之间存在很强的相关性，这反过来又影响模拟的预测平均投票率（PMV）。绿化的影响更显着的块与低SVI，其中近50%的网站被树木和草地覆盖，相比之下，只有0.02%的其他块与高SVI。此外，调查发现，减少SVF，沿着增加的高湿比和高湿比，对两个研究的城市街区内行人水平的小气候产生了有益的影响。该研究为解决精细地理尺度下室外热舒适与城市形态的不公平问题提供了一种有效且易于实现的方法。
Urban areas are often warmer than rural areas due to the phenomenon known as the “urban heat island” (UHI) effect, which can cause discomfort for those engaging in outdoor activities and can have a disproportionate impact on low-income communities, people of color, and the elderly. The intensity of the UHI effect is influenced by a variety of factors, including urban morphology, which can vary from one area to another. To investigate the relationship between outdoor thermal comfort and urban morphology in different urban blocks with varying social vulnerability status, this study developed a geographic information system (GIS)-based workflow that combined the “local climate zone” (LCZ) classification system and an urban microclimate assessment tool called ENVI-met. To demonstrate the effectiveness of this methodology, the study selected two different urban blocks in Philadelphia, Pennsylvania–with high and low social vulnerability indices (SVI)–to compare their microclimate conditions in association with urban morphological characteristics such as green coverage area, sky view factor (SVF), albedo, and street height to width (H/W) ratio. The results of the study showed that there was a strong correlation between tree and grass coverage and outdoor air and mean radiant temperature during hot seasons and extremely hot days, which in turn affected simulated predicted mean vote (PMV). The effects of greenery were more significant in the block associated with a low SVI, where nearly 50% of the site was covered by trees and grass, compared to only 0.02% of the other block associated with a high SVI. Furthermore, the investigation discovered that reduced SVF, along with increased albedo and H/W ratio, had a beneficial impact on the microclimate at the pedestrian level within the two studied urban blocks. This study provided an effective and easy-to-implement method for tackling the inequity issue of outdoor thermal comfort and urban morphology at fine geographic scales.