城市街区异质景观的热环境效应及其优化模拟

Increasing awareness of the urban heat island (UHI) effect has raised attention about the heat environment in cities worldwide. Urban block is the basic element in city, its thermal behavior significantly contributed to the thermal environment in urban scale. One of the important aspects in the planning of urban block is the impact of composition and configuration of landscape on micro-scale climate. Hence exploring the thermal environment effect of heterogeneous landscape in urban block and adopting corresponding landscape optimization schemes to create a better thermal environment and thermal comfort conditions become urgent problems during sustainable planning. This proposal will take the urban central area of Guangzhou as a case study, combine land surface temperature (LST) analysis derived from remote sensing data with micro-scale thermal environment field measurements and simulations in selected urban blocks, to explain thermal environment effect of heterogeneous landscape and their optimization schemes. This proposal intends to investigate three key research aspects, 1) detect the key landscape factors which deriving summer thermal environment in urban block; 2) reclassify the urban blocks type according to the key landscape factors results, then conducting thermal environment field measurements to investigate the 3-demension dynamic processes and differences of thermal environment across space and time; 3) conduct thermal environment simulations and predictions through micro-scale climate model ENVI-met, in order to explore the landscape optimization schemes with the aim of improving thermal environment in urban block. Results from this proposal will improve our understanding of the complicated mechanisms of landscape pattern and their thermal environment processes, promote the study of thermal environment to the micro-scale geographical unit, and provide scientific basis for improving thermal environment and constructing livable city.

街区是城市空间的基本组成单元，其热力性质是构成城市热环境的重要因素，综合评估城市街区异质景观的热环境效应，及采取相应的景观优化方案改善街区热环境，是开展城市景观规划亟需考虑的问题。本项目以广州市中心城区为研究案例，尝试以热红外遥感影像分析为基础，结合典型街区热环境实测和模拟的方法，探讨城市街区异质景观的夏季热环境效应及其优化方案，拟开展三方面研究：1）基于热红外遥感影像识别影响街区夏季热环境的关键景观要素；2）根据关键景观要素识别结果进行街区类型划分，开展典型街区夏季热环境实测，探讨不同类型街区热环境的三维时空动态过程及其差异；3）以改善热环境为导向，利用ENVI-met模型开展街区热环境模拟与预测，探讨街区景观优化方案。本项目研究结果有助于揭示街区异质景观“格局”和热环境“过程”的关系，推进热环境研究向精细化的城市地域单元深入发展，为改善城市热环境和构建宜居城市提供科学依据。

本项目以高度城市化的珠三角核心城市为例，深入分析了城市景观格局的热环境效应机理，开展了城市绿地景观格局提取和城市热岛范围提取工作（见已授权的发明专利“一种城市热岛范围的提取方法及装置”），定量对比分析了不同城市内部绿地格局特征，及其对热环境影响的时空尺度效应（见2019年在Science of The Total Environment期刊发表的论文），借鉴了景观生态学空间异质性的核心思想，将其引入到城市景观特征的热环境机理当中，提出了建筑和绿地对热环境作用的空间异质性模型（见2019年在Sustainable Cities and Society发表的论文，以及发明专利“一种城市热环境成因诊断方法及系统”），创新性地提出了绿地景观作用于城市热环境的多尺度模型以及不同尺度上的主控因素（见2020年发表在Sustainable Cities and Society的论文，和发明专利“一种城市热岛主控因素的分析方法、装置及存储介质”），同时也提出了城市热环境主控要素的空间制图方法（见发明专利“一种影响城市热环境的关键绿地格局指数筛选方法及系统”和“一种城市热环境主控因素的空间制图方法、装置及介质”）。本项目深化了人民关于城市景观格局对热环境作用的认知，为改善城市热环境和构建宜居城市提供科学依据。