Environmental Health Department, Graduate School of Public Health, University of Puerto, Rico, Medical Sciences Campus, P.O. Box 365067, San Juan, 00936, Puerto Rico.
Institute for Marine Remote Sensing, College of Marine Science, University of South Florida, 140 7th Ave. South, St. Petersburg, FL, 33701, USA.
Int J Biometeorol. 2018 May;62(5):709-722. doi: 10.1007/s00484-017-1319-z. Epub 2017 Feb 17.
Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate the potential effects of heat-related illnesses.
在美国波多黎各岛首府圣胡安，高温天气出现的频率和持续时间都有所增加，由此导致心血管问题和哮喘病的发病率呈上升趋势。城市热岛效应会导致部分城市地区出现高温焦点，从而增加与热相关的死亡率。本研究的目的是通过绘制圣胡安市的高温热图，定位特定地点的高温风险。利用基于卫星的遥感收集的图像并结合人口普查数据，制作了热脆弱性指数（HVI）图。使用搭载在 Landsat 8 卫星上的热红外传感器拍摄的图像评估地表温度。通过人口普查区分析社会决定因素（例如年龄、失业、教育和社会隔离以及医疗保险覆盖范围）。根据波多黎各陆地差距分析项目（美国农业部林务局）生成的土地覆盖图来检查数据。将所有变量设置为将以不同单位表示的指标转换为 0 到 1 之间的指数，并将 HVI 计算为得分总和。指数最高的地段被认为是最脆弱的，而指数最低的地段则被认为是最不脆弱的。共绘制了五个脆弱性类别（极高、高、中、低和极低）。最热和最脆弱的地段与高度发达的地区相对应，包括路易斯·穆尼奥斯·马林国际机场、海港、停车场和高密度住宅区。包括独居人口比例较高、残疾、高龄和缺乏医疗保险等在内的多个变量导致了脆弱性的增加。最凉爽的地区对应于植被景观和城市水体。城市 HVI 图将对卫生官员、应急准备人员、国家气象局和圣胡安居民有用，因为它有助于为与热相关的疾病的潜在影响做准备和减轻其影响。
