A social vulnerability study of the urban heat island effect in Baltimore and St. Louis

Abstract

Extreme heat events (EHEs) are increasing in frequency, intensity, and duration with modern climate change. An urban heat island (UHI) is a phenomenon where built environments such as cities experience elevated temperatures compared to surrounding rural areas. The UHI effect exacerbates the consequences of EHEs, leaving those in cities generally more exposed to higher temperatures. The intra-urban variability within cities, both in terms of the physical environment and demographic characteristics, can potentially leave some populations more vulnerable to EHEs. This research focuses on intra-urban vulnerability to EHEs in two cities, Baltimore and St. Louis. The study uses remote sensing and GIS methods to measure the UHI effect, correlates temperature with demographic variables by block group, creates a score measuring populations’ sensitivity to EHEs, and assesses vulnerability through a heat vulnerability index. Results indicate relationships between exposure and sensitivity and how they relate to the vulnerability within the cities. Overall, there is no ubiquitous pattern of vulnerability that can be found in both cities. The results could be utilized by planners or policymakers to target vulnerable areas and implement mitigation and adaptive strategies to cope with the effects of EHEs unique to each city.