Space-time dynamics in extreme-heat hazard exposure analysis

Keywords: Extreme heat, Mobility data, Hazard exposure, Heat mitigation
Abstract Type: Virtual Paper Abstract

Abstract

Time geography has set the grounds for including the dynamic aspect of spatial and temporal processes in geographical studies, and the application of mobility data is a tool for addressing it empirically. With the availability of mobile-phone data, larger number of GPS devices, and social platforms like Twitter, several studies have benefitted from this growing source of information in analyzing the exposure to hazards, from air pollution to pandemics. Hazards, either climatic or anthropogenic, have unique characteristics that reflect the dynamic processes involved, requiring adaptive methods of analysis to include these spatio-temporal attributes. Often studies of vulnerability are place-based (i.e., where people reside), with limitations on where people are during the day. Recently, mobility data provided insights on control measures during the COVID-19 pandemic, and in the study of hurricane evacuations. We present a new perspective in applying the mobile-phone data for measuring the exposure to extreme heat events (based on behavioral pattern changes in indoor and outdoor space use, between control days and heat events). The results of testing the explanatory power of exposure measure in relation to two metrics of cooling center use and shade use for mitigation method assessment, and in relation to excess emergency room visits as an outcome measure highlights disproportionate impacts, inelasticity in shade-seeking behaviors, and efficacy of cooling centers (study area of Los Angeles County, California, US). This method has the potential for application in other regions in the vulnerability assessments and mitigation planning.