College of Environment and Safety Engineering, Fuzhou University, Fuzhou, China.
School of Public Health, Fudan University, Shanghai, China.
Front Public Health. 2022 Oct 20;10:989963. doi: 10.3389/fpubh.2022.989963. eCollection 2022.
Extreme heat caused by global climate change has become a serious threat to the sustainable development of urban areas. Scientific assessment of the impacts of extreme heat on urban areas and in-depth knowledge of the cross-scale mechanisms of heat vulnerability forming in urban systems are expected to support policymakers and stakeholders in developing effective policies to mitigate the economic, social, and health risks. Based on the perspective of the human-environment system, this study constructed a conceptual framework and index system of "exposure-susceptibility-adaptive capacity" for urban heat vulnerability (UHV) and proposed its assessment methods. Taking Xiamen City, a coastal metropolis, as an example, spatial analysis and Geodetector were used to explore the spatial and temporal changes, spatial characteristics, and patterns of UHV under multiple external disturbances from natural to anthropological factors, and to reveal the main factors influencing UHV forming and spatial differentiation. Results showed that the exposure, susceptibility, adaptive capacity, and UHV in Xiamen City had a spatial structure of "coastal-offshore-inland". On the hot day, both the exposure and UHV showed a temporal pattern of "rising and then falling, peaking at 14:00" and a spatial pattern of "monsoonal-like" movement between coast and inland. Coastal zoning with favorable socioeconomic conditions had less magnitude of changes in UHV, where the stability of the urban system was more likely to be maintained. During the hot months, the high UHV areas were mainly distributed in the inland, while coastal areas showed low UHV levels. Further, coastal UHV was mainly dominated by "heat exposure", offshore by "comprehensive factors", and inland in the northern mountainous areas by "lack of adaptive capacity". Multi-scale urban adaptive capacity was confirmed to alter spatial distribution of exposure and reshape the spatial pattern of UHV. This study promotes the application of multi-scale vulnerability framework to disaster impact assessment, enriches the scientific knowledge of the urban system vulnerability, and provides scientific references for local targeted cooling policy development and extreme heat resilience building programs.
由全球气候变化引起的极端高温已经成为城市可持续发展的严重威胁。科学评估极端高温对城市地区的影响，深入了解城市系统中热脆弱性形成的跨尺度机制，有望为政策制定者和利益相关者提供支持，以制定有效的政策来减轻经济、社会和健康风险。本研究基于人-环境系统视角，构建了城市热脆弱性（UHV）的“暴露-易损性-适应能力”概念框架和指标体系，并提出了评估方法。以沿海大都市厦门市为例，运用空间分析和地理探测器方法，探讨了自然到人为因素等多种外部干扰下 UHV 的时空变化、空间特征和格局，揭示了影响 UHV 形成和空间分异的主要因素。结果表明，厦门市的暴露度、易损性、适应能力和 UHV 具有“沿海-近海-内陆”的空间结构。在炎热天气下，暴露度和 UHV 均呈现出“先升后降、14:00 达到峰值”的时间格局和“季风型”由沿海向内陆移动的空间格局。具有良好社会经济条件的沿海区域，UHV 的变化幅度较小，城市系统的稳定性更有可能得到维持。在炎热月份，高 UHV 区域主要分布在内陆，而沿海区域则表现出较低的 UHV 水平。此外，沿海 UHV 主要受“热暴露”主导，近海地区受“综合因素”主导，内陆北部山区则受“适应能力不足”主导。多尺度城市适应能力改变了暴露度的空间分布，重塑了 UHV 的空间格局。本研究促进了多尺度脆弱性框架在灾害影响评估中的应用，丰富了城市系统脆弱性的科学知识，为地方有针对性的冷却政策制定和极端高温抵御计划提供了科学参考。
