Human-centric characterization of life activity flood exposure shifts focus from places to people

A human-centric approach to assessing flood exposure moves beyond traditional spatial assessment by quantifying flood exposure based on life activity. This novel method characterizes flood exposure by measuring dwell time in flood-prone areas, using fine-resolution, anonymized smartphone data. Comparative analysis across 18 US cities reveals important disparities in life activity flood exposure (LAFE) and highlights the influence of urban forms and structures on LAFE. Furthermore, the research uncovers bimodal distributions in LAFE, indicating disparities even among cities with similar spatial flood risks. By focusing on the effect of daily human activities in flood-prone areas, this approach offers a more comprehensive understanding of flood impacts on daily activities and socioeconomic factors. The findings provide urban scientists and flood risk managers with a practical tool, underscoring the importance of human activity patterns in flood risk assessment, and offer valuable insights for enhanced analysis of flood exposure and risk. Flood risk exposure has traditionally focused on people's place of residence, but people do not spend all day in their homes. This Article depicts a more complex story by place and time of day, arguing that flood risk exposure is more complex than what traditional measures show.