University of California, Berkeley, Department of Landscape Architecture and Environmental Planning, Berkeley, CA, United States of America.
University of California, Berkeley, School of Public Health, Berkeley, CA, United States of America.
Sci Total Environ. 2024 Nov 1;949:175284. doi: 10.1016/j.scitotenv.2024.175284. Epub 2024 Aug 3.
This study investigates the relationship between temporal changes in temperatures characterizing local urban heat islands (UHIs) and heat-related illnesses (HRIs) in seven major cities of California. UHIs, which are a phenomenon that arises in the presence of impervious surfaces or the lack of green spaces exacerbate the effects of extreme heat events, can be measured longitudinally using satellite products. The two objectives of this study were: (1) to identify temperature trends in local temperatures to characterize UHIs across zip code tabulation areas (ZCTAs) in the seven observed cities over a 22-year period and (2) to use propensity score and inverse probability weighting to achieve exchangeability between different types of ZCTAs and assess the difference in hospital admissions recorded as HRIs attributable to temporal changes in UHIs. We use monthly land surface temperature data derived from MODIS Terra imagery from the summer months (June-September) from 2000 to 2022. We categorized ZCTAs (into three groups) based on their monthly land surface temperature trends. Of the 216 ZCTAs included in this study, the summertime land surface temperature trends of 43 decreased, while 161 remained unchanged, and 12 increased. Los Angeles had the greatest number of decreased ZCTAs, San Diego and San Jose had the highest number of increased ZCTAs. To analyze the number of monthly HRI attributable to changes in UHI, we used inverse probability of treatment weighting to analyze the difference in HRI between the years of 2006 and 2017 which were two major extreme heat events over the entire State. We observed an average reduction of 3.2 (95 % CI: 0.5; 5.9) HRIs per month and per ZCTAs in decreased neighborhoods as compared to unchanged. This study emphasizes the importance of urban climate adaptation strategies to mitigate the intensity and prevalence of UHIs to reduce health risks related to heat.
本研究调查了加利福尼亚州七个主要城市的局部城市热岛（UHI）温度随时间的变化与与热相关疾病（HRI）之间的关系。UHI 是一种在不透水面存在或缺乏绿色空间的情况下出现的现象，会加剧极端高温事件的影响，可以使用卫星产品进行纵向测量。本研究的两个目标是：（1）确定当地温度的趋势，以在 22 年的时间内描述七个观测城市的邮政编码区（ZCTA）中的 UHI；（2）使用倾向评分和逆概率加权来实现不同类型的 ZCTA 之间的可交换性，并评估归因于 UHI 时间变化的医院就诊人数的差异。我们使用 2000 年至 2022 年夏季（6 月至 9 月）从 MODIS Terra 图像中提取的每月土地表面温度数据。我们根据每月土地表面温度趋势将 ZCTA（分为三组）。在本研究中包含的 216 个 ZCTA 中，43 个的夏季土地表面温度趋势下降，而 161 个保持不变，12 个上升。洛杉矶有最多的 ZCTA 减少，圣地亚哥和圣何塞有最多的 ZCTA 增加。为了分析归因于 UHI 变化的每月 HRI 数量，我们使用治疗逆概率加权来分析 2006 年和 2017 年（整个州的两个主要极端高温事件）之间的 HRI 差异。与不变的 ZCTA 相比，我们观察到下降的社区中每月每个 ZCTA 的 HRI 减少了 3.2（95%CI：0.5；5.9）。本研究强调了城市气候适应策略的重要性，以减轻 UHI 的强度和普遍性，从而降低与热相关的健康风险。
