City population groupings.

This paper seeks to: 1) determine the extent of the intra-urban surface urban heat island (SUHI) effect within German cities using novel urbanization-level data with high spatial resolution, and 2) to assess the influence of city size and urban form using this data together with landscape metrics. The study uses aggregated Landsat LST data to measure the intra-urban SUHI effect across German cities of various population sizes. The first stage of the research utilizes urbanization-level data based on differing thresholds of population and building density, providing a novel method of measuring the correlation between the intra-urban SUHI phenomenon and density. The second stage assesses the impact of urban form by calculating specific landscape metrics using high-resolution land cover data, which is then clustered to identify homogeneous patterns among cities. We show that the SUHI effect can be found within all cities included in the study; however, a positive correlation between increase in city size and increase in heat stress could not be confirmed. The study shows that German urban areas are characterized by specific patterns of urban form that correspond with size, and specific urban forms particularly related to density and shape correspond with higher overall LST.本研究旨在达成两大研究目标：其一，依托高空间分辨率的新型城市化分级数据集，测算德国各城市内部的地表城市热岛（Surface Urban Heat Island, SUHI）效应强度；其二，结合该数据集与景观格局指数，评估城市规模与城市形态对热岛效应的影响。本研究采用聚合后的陆地卫星LST数据，对不同人口规模的德国城市的城市内部SUHI效应进行测算。研究第一阶段采用基于不同人口与建筑密度阈值的城市化分级数据集，提出了一种测算城市内部SUHI现象与密度相关性的全新方法。第二阶段则通过高分辨率土地覆盖数据计算特定景观格局指数，随后对城市样本进行聚类分析，以识别不同城市间的同质化空间形态模式。研究结果显示，本研究涵盖的所有德国城市均存在城市内部SUHI效应；但未证实城市规模扩张与热胁迫加剧之间存在显著正相关关系。本研究表明，德国城市区域呈现出与城市规模相匹配的特定城市形态模式，而与密度及空间形态密切相关的特定城市形态，则对应更高的整体地表温度。