Zhenyu Gai , Haiwei Yin , Fanhua Kong , Jie Su , Zhou Shen , Hui Sun , Shaoqi Yang , Hongqing Liu , Ariane Middel
{"title":"How does shade infrastructure affect outdoor thermal comfort during hot, humid summers? Evidence from Nanjing, China","authors":"Zhenyu Gai , Haiwei Yin , Fanhua Kong , Jie Su , Zhou Shen , Hui Sun , Shaoqi Yang , Hongqing Liu , Ariane Middel","doi":"10.1016/j.buildenv.2024.112320","DOIUrl":null,"url":null,"abstract":"<div><div>With global climate change and urbanization, the urban heat island effect and extreme heat have negatively affected the outdoor thermal comfort (OTC) of urban residents. Therefore, it is critical to investigate how the built environment affects OTC to improve urban design and promote outdoor activities. Trees increase OTC under hot, sunny conditions, and dynamic shade cast from buildings has also been found to affect OTC positively. However, limited research has been conducted to understand the synergistic cooling effects of trees and building shade on OTC. Taking Nanjing City, China, as the study area, this study investigates the differences and synergistic effects of various urban shade infrastructure on OTC. The ENVI-met model was used to simulate two scenarios with and without trees, and physiological equivalent temperature (PET) was calculated to quantify OTC. The results show that tree removal increased air temperature, wind speed, direct shortwave radiation, and decreased relative humidity, leading to an increase in PET by about 5.9 to 9.4 °C. Our shade analysis reveals that building shade can reduce PET by around 5.1 to 9.8 °C. Overall, urban shade infrastructure (mainly including trees and buildings) can reduce PET by around 9.4 to 17.1 °C synergistically. The nonlinear relationship of tree structural characteristics related to PET is further discussed to determine planning priorities and propose heat mitigation strategies to optimize physical spaces. We recommend combining dynamic shade from various urban infrastructure to improve OTC in the summer, improving urban outdoor livability.</div></div>","PeriodicalId":9273,"journal":{"name":"Building and Environment","volume":"267 ","pages":"Article 112320"},"PeriodicalIF":7.1000,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Building and Environment","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0360132324011624","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
With global climate change and urbanization, the urban heat island effect and extreme heat have negatively affected the outdoor thermal comfort (OTC) of urban residents. Therefore, it is critical to investigate how the built environment affects OTC to improve urban design and promote outdoor activities. Trees increase OTC under hot, sunny conditions, and dynamic shade cast from buildings has also been found to affect OTC positively. However, limited research has been conducted to understand the synergistic cooling effects of trees and building shade on OTC. Taking Nanjing City, China, as the study area, this study investigates the differences and synergistic effects of various urban shade infrastructure on OTC. The ENVI-met model was used to simulate two scenarios with and without trees, and physiological equivalent temperature (PET) was calculated to quantify OTC. The results show that tree removal increased air temperature, wind speed, direct shortwave radiation, and decreased relative humidity, leading to an increase in PET by about 5.9 to 9.4 °C. Our shade analysis reveals that building shade can reduce PET by around 5.1 to 9.8 °C. Overall, urban shade infrastructure (mainly including trees and buildings) can reduce PET by around 9.4 to 17.1 °C synergistically. The nonlinear relationship of tree structural characteristics related to PET is further discussed to determine planning priorities and propose heat mitigation strategies to optimize physical spaces. We recommend combining dynamic shade from various urban infrastructure to improve OTC in the summer, improving urban outdoor livability.
期刊介绍:
Building and Environment, an international journal, is dedicated to publishing original research papers, comprehensive review articles, editorials, and short communications in the fields of building science, urban physics, and human interaction with the indoor and outdoor built environment. The journal emphasizes innovative technologies and knowledge verified through measurement and analysis. It covers environmental performance across various spatial scales, from cities and communities to buildings and systems, fostering collaborative, multi-disciplinary research with broader significance.