  Improving hurricane preparedness is essential to reduce hurricane impacts.
Inherent in traditional methods for quantifying and monitoring hurricane
preparedness are significant lags. This study establishes a methodological
framework to quantify the extent, timing, and spatial variation of hurricane
preparedness at the CBG level using high-resolution location intelligence data.
Anonymized cell phone data on visits to POIs for each CBG before 2017 Hurricane
Harvey were used to examine hurricane preparedness. Four categories of POI,
grocery stores, gas stations, pharmacies and home improvement stores, were
identified as having close relationship with hurricane preparedness, and the
daily number of visits from each CBG to these four categories of POIs were
calculated during preparation period. Two metrics, extent of preparedness and
proactivity, were calculated based on the daily visit percentage change
compared to the baseline period. The results show that peak visits to
pharmacies often occurred in the early stage, whereas the peak of visits to gas
stations happened closer to landfall. The spatial and temporal patterns of
visits to grocery stores and home improvement stores were quite similar.
However, correlation analysis demonstrates that extent of preparedness and
proactivity are independent of each other. Combined with synchronous evacuation
data, CBGs were divided into four clusters in terms of extent of preparedness
and evacuation rate. The clusters with low preparedness and low evacuation rate
were identified as hotspots of vulnerability for shelter-in-place households
that would need urgent attention during response. The study advances
data-driven understanding of human protective actions and provide emergency
response managers with novel insights to proactively monitor disaster
preparedness, facilitating identifying under-prepared areas and better
allocating resources timely.
