InfruTreeCity: Understanding Infrared radiative performance of urban trees for better future city

城市绿地和树木对人们的健康、热舒适、减少污染和噪音、可持续城市排水和碳封存都有实质性的有益影响。在预计的气候变化下，城镇和城市的夏季热舒适和冷却能源消耗将受到越来越多的热应力的影响，研究重点是城市树木的辐射热性能。树木和绿地提供了显著的降温效果，从而有助于在城镇和城市创造舒适的小气候。它们在改善城市热岛效应方面也很有效，尽管程度较低。被树木遮蔽的建筑物的冷却负荷减少了25-50%，通常不需要耗能的机械冷却。由于缺乏基本的见解和定量信息，建筑设计师和城市规划者在城市环境中有效利用树木和绿色空间受到阻碍。研究发现，不同树种的冠层表面温度差异可达9摄氏度。为城市种植计划选择合适的树种对于最大限度地发挥其降温效果至关重要，但目前还没有系统的信息。另一个障碍是缺乏综合的多学科方法来调查城市树木的热性能，其中一棵树或一组树木被视为“黑箱”，即不考虑基本的物理和（植物）生理过程，也不考虑城市环境对这些过程的影响。因此，研究结果对其他城市环境的适用性有限。至关重要的是，红外辐射占到达地球的太阳辐射的50%以上，这在以前的研究中基本上是缺失的。该研究旨在通过研究城市树木与建筑环境的相互作用，重点研究红外辐射能量交换，并在城市夏季过热预防的背景下克服这些障碍。具体目标包括：-基于将建筑和气候物理学与植物生理学结合起来的多学科方法，首次量化选定的常见城市树木的辐射和其他冷却机制，处理辐射能量交换、树木生理过程、城市建筑形式和材料以及树木形式和物种的影响；-为建筑/园景设计师及城市规划师提供指引，使城镇树木得以有效地整合，包括选择树种、适当的城市形态及建筑材料；-开发一套网上展示工具，以便快速查阅和有效利用工作的成果和指引。

Urban green spaces and trees have substantial beneficial effects on people's health, thermal comfort, pollution and noise reduction, sustainable urban drainage and carbon sequestration. The proposed research focuses on the radiative thermal performance of urban trees in the context of summer thermal comfort and cooling energy consumption in towns and cities that are subject to increasing heat stress under projected climate change.Trees and green spaces offer significant cooling benefits, thereby helping to create comfortable micro-climates in towns and cities. They are also effective, though to a lesser extent, in ameliorating the urban heat island (UHI) effect. Buildings shaded by trees experience 25-50% reduction of cooling load, often removing the need for energy intensive mechanical cooling. The effective use of trees and green spaces in urban environments by building designers and urban planners has been impeded by the lack of fundamental insights and quantitative information. It has been found that tree species differ by up to 9C in their canopy surface temperatures. Choosing the right tree species for urban planting schemes is critical for maximizing their cooling effects, but systematic information is currently not available. A further obstacle is the lack of an integrated multidisciplinary approach to the investigation of thermal performance of urban trees, where a tree or a group of trees were treated as a 'black box' , i.e., without consideration of the fundamental physical and (plant) physiological processes, nor the influence of the urban environment on these processes. The results thus have limited applicability to other urban settings. Crucially, the consideration of infrared radiation, which accounts for over 50% of the solar radiation reaching the Earth, is largely missing in previous investigations. The proposed study aims to overcome these obstacles by investigating urban tree - built environment interactions, focusing on infrared radiative energy exchange, and in the context of prevention of summer overheating in cities. Specific objectives include:- quantify, for the first time, radiative and other cooling mechanisms of selected common urban trees based on a multidisciplinary approach that integrates building and climate physics with plant physiology, addressing radiative energy exchange, tree physiological processes, urban built forms and materials and the influences of tree forms and species;- provide guidance to building / landscape designers and urban planners for effective integration of trees in towns and cities including tree species selection and appropriate urban form and building materials; - develop an online presentation tool to allow rapid access to and effective utilisation of the results and guidance generated from the work.