A newly published paper by DRRN member Ethan Raker and Xueqing Zhang introduces a new way to measure the population burden of wildfire and flood evacuation orders in British Columbia. Using data from 2017 to 2023, it calculates person-days under emergency orders to understand how long and how many people were affected. The study finds that 2.71 million person-days were spent under mandatory evacuation, with wildfire evacuations making up the majority. It also highlights social disparities, showing that Indigenous and low-income communities faced a disproportionate burden. The research suggests that person-time measures could help better assess the impact of environmental hazards.
Abstract:
This research brief introduces a novel quantity to estimate the population burden of environmental emergency orders: EOpd,j, the person-days, pd, in geographic region, j, under an emergency order (EO). Using the case of evacuations, we pair spatial data on every mandatory evacuation for wildfires and floods in British Columbia from 2017 to 2023 with local data on population demographics from the 2016 Canadian census. Empirically, we describe the EOpd,j over years and by hazard at the provincial level, and then estimate community-level EOpd,j and bivariate correlations with sociodemographics across census subdivisions (municipalities and equivalents). During this period, the provincial-level EOpd,j was 2.71 million person-days under mandatory evacuation order. Evacuation mandates affected 34% of subdivisions, and among affected communities, the average EOpd,j was 12,085 person-days. We find that per-capita EOpd,j correlated positively with the share of Indigenous people, low-income residents, and adults with high-school-or-less education. Person-time measures of emergency orders provide insight into the population burden of environmental hazards across contexts, can easily be extended to other cases, such as air quality alerts or heat warnings, and may help demographers study direct environmental effects or effect moderation across places.
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