Zhang Huina, Zhang Jun, Fediuk Roman, Qi Ruoming, Xu Jia, Bai He, Guo Yingchu
College of Landscape Architecture, Northeast Forestry University, Harbin, 150040, China.
Polytechnic Institute, Far Eastern Federal University, Vladivostok, 690922, Russian Federation.
Sci Rep. 2025 May 4;15(1):15588. doi: 10.1038/s41598-025-00032-3.
Increasing thermal discomfort and thermal exposure threaten the health and well-being of urban residents. Existing research is usually limited to a single scale such as city-level and regional level. In addition, little has been reported on the differences in the inequality of population thermal exposure. In this paper, the Modified Temperature and Humidity Index (MTHI), population-weighted exposure model, and Gini coefficient (GINI) were applied to assess thermal comfort, thermal exposure, and inequality of thermal exposure at multiple scales (city-level, county-level, town-level and parcel-level) in Zhengzhou city from 1990 to 2020. Heat risks in the study area were assessed and risk categories of the assessment units were classified. The results showed that in the past three decades, the thermal comfort of residents had gradually decreased, and the degree of thermal exposure had steadily increased. Thermal exposure inequality coefficients showed complex variations at different scales and regions. The assessment of multi-scale administrative districts had a significant scale effect, indicating that the finer the spatial scale, the stronger the heterogeneity. In 2020, 27 towns had thermal discomfort; 24 towns were characterized by high thermal exposure; and 24 towns had inequality in thermal exposure. 305 parcels had thermal discomfort; 239 parcels were characterized by high thermal exposure; and 64 parcels had inequality in thermal exposure. The heat risk assessment showed that the towns with lower heat risk were mainly located in the central and northern areas of Zhengzhou. The heat risk values of the parcels in the urban center area were polarized. The heat risk categories were dominated by thermal comfort-low exposure-low inequality and thermal discomfort-high exposure-low inequality. This research could lead to a better understanding of thermal exposure and thermal exposure inequality at multiple scales, contributing to improved environmental justice and sustainable urban development.
日益增加的热不适和热暴露威胁着城市居民的健康和福祉。现有研究通常局限于单一尺度，如城市层面和区域层面。此外，关于人口热暴露不平等差异的报道较少。本文应用修正温湿度指数（MTHI）、人口加权暴露模型和基尼系数（GINI），对1990年至2020年郑州市多尺度（城市层面、县级层面、镇级层面和地块层面）的热舒适度、热暴露和热暴露不平等进行评估。对研究区域的热风险进行评估，并对评估单元的风险类别进行分类。结果表明，在过去三十年中，居民的热舒适度逐渐下降，热暴露程度稳步上升。热暴露不平等系数在不同尺度和区域呈现复杂变化。多尺度行政区评估具有显著的尺度效应，表明空间尺度越精细，异质性越强。2020年，有27个镇存在热不适；24个镇热暴露程度高；24个镇存在热暴露不平等。305个地块存在热不适；239个地块热暴露程度高；64个地块存在热暴露不平等。热风险评估表明，热风险较低的镇主要位于郑州市的中部和北部地区。城市中心区域地块的热风险值呈两极分化。热风险类别以热舒适-低暴露-低不平等和热不适-高暴露-低不平等为主。本研究有助于更好地理解多尺度下的热暴露和热暴露不平等，促进环境公平和城市可持续发展。
