Abstract: It is crucial to understand the relationship between the complicated spatial morphology of cities and their thermal environment to deal with the increasing risks of high-temperature heat waves. Hence, a case study based on Macao was conducted. First, the optimal partition scale (120 m × 120 m) of local climate zones (LCZs) was determined using the semi-variogram function and Pearson correlation coefficient. The LCZs in Macao were delineated by remote sensing interpretation in ENVI, GIS spatial analysis, CART decision tree classification, and other methods. Second, surface temperature data in Macao were collected using remote sensing image inversion techniques. Eight urban morphological indicators with significant correlations with the thermal environment, namely sky view factor (SVF), building density (BD), building volume density (BVD), building height (BH), building height variation (BH_S), impervious surface density (ISD), green space density (GSD), and water surface density (WSD), were acquired via the ArcGIS data analysis technique as independent variables. Later, the correlations between independent and dependent variables were analyzed quantitatively through a spatial error model (SEM) with the best fitting effect, thus disclosing the key influencing factors and mechanisms of thermal environments in different subzones of LCZs. Finally, the thermal environment optimization level of each subzone of LCZs was evaluated comprehensively from "Optimization Necessity (ON), Optimization Effectiveness (OE), Strategy Effectiveness (SE), and Strategy Feasibility (SF)". Optimization suggestions were then proposed based on the evaluation results. The results demonstrated that: 1) The northern regions of the Macao Peninsula are dominated by LCZ2 (compact mid-rise), LCZ4 (open high-rise), and LCZ5 (open mid-rise), with a small number of green space-type LCZs (LCZA~D). The southern regions of Taipa, Coloane, and Cotai have more blue-green spaces, and open-formed LCZs dominate built-type LCZs. 2) LCZs dominated by medium-low-rise buildings (LCZ6~10) and bare ground (LCZE~F) exhibit significant warming effects, whereas LCZs dominated by trees (LCZA~B), water bodies (LCZG), and high-rise buildings (LCZ1, LCZ4) exhibit significant cooling effects. The cooling effect of shrubs and low vegetation (LCZC~D) is less prominent. For built-up LCZs, blocking solar radiation is more favorable for cooling than ventilation and heat dissipation approaches. 3) The SEM better describes the relationship between urban morphology and the thermal environment in Macao. However, it also demonstrated that other variables or independent error terms might affect the surface temperature, which shall be further analyzed and discussed in future studies. 4) The key influencing factors and their coefficients vary significantly among different subzones of LCZs, indicating that adaptive thermal environment optimization strategies shall be selected for different subzones of LCZs. 5) SVF, BD, BVD, and ISD exhibit warming effects, whereas BH, BH_S, GSD, and WSD present cooling effects. Influencing coefficients of GSD, WSD, ISD, and BVD are generally high. 6) Macao is recommended to first optimize the thermal environment in LCZ10 (heavy industry), LCZF (bare soil or sand), LCZ4 (open high-rise), LCZ5 (open mid-rise), LCZA (dense trees), and LCZ6 (open low-rise). In addition, crucial influencing factors shall be determined by combining SEM for differentiated planning and design of spatial elements in each subzone. This study supports formulating countermeasures to high-temperature risks in high-density cities like Macao.

Key words: local climate zones, urban thermal environment, land surface temperature, urban morphology, spatial error model, Macao

摘要： 为应对日益严峻的高温热浪风险，明晰城市复杂的空间形态与热环境的关系，以澳门为例，首先，通过ENVI遥感解译、GIS空间分析、CART决策树分类等方法划定局地气候区（LCZs）；其次，利用空间误差模型（SEM）分析LCZs热环境的关键影响因子和影响机制；最后结合热环境优化等级评估，提出优化建议。结果表明：1）以中低层建筑、裸露地表为主的LCZs升温效应显著；以乔木、水体和高层建筑为主的LCZs降温效应显著；2）阻挡太阳辐射比通风散热更有利于地表降温；3）空间误差模型（SEM）能较好地描述澳门城市形态与热环境的关系；4）各LCZs分区热环境影响因子及影响机制差异较大；5）SVF、BD、BVD和ISD具有增温效应，BH、BH_S、GSD和WSD具有降温效应，且GSD、WSD、ISD和BVD的影响系数普遍较高；6）澳门宜优先优化LCZ10（重工业）、LCZF（裸土或沙）、LCZ4（开阔高层）、LCZ5（开阔中层）、LCZA（茂密树木）、LCZ6（开阔低层）热环境。将为澳门等高密度城市制定高温风险应对决策提供支持。

关键词: 局地气候区, 城市热环境, 地表温度, 城市形态, 空间误差模型, 澳门