Spatial Patterns of Post-Storm Recovery Revealed by Nighttime Lights: Evidence from Harris County, Texas

Winter Storm Uri (February 2021) caused the largest power grid failure in Texas history, with extensive outages in the state's most populous Harris County. This study integrates NASA Black Marble VNP46A2 nighttime light (NTL) observations with the CDC Social Vulnerability Index (SVI) to characterize post-storm recovery across 1,070 census tracts. Recovery was defined as the first day tract-level NTL reached at least 90% of its pre-storm baseline for three consecutive days. Contrary to the expectation that vulnerable communities recover more slowly, spatial regression revealed a weak, statistically significant negative association between SVI and recovery time (β = −0.556, p = 0.050), with spatial dependence also significant (ρ ≈ 0.47). Local Indicators of Spatial Autocorrelation identified significant clusters of slow recovery in lower-SVI suburban areas and fast recovery in higher-SVI urban neighborhoods. This association was sensitive to the recovery definition, reversing signs under longer persistence requirements. The spatial organization of urban infrastructure, rather than vulnerability alone, may plausibly explain these patterns, though not directly testable with available data. These findings caution against assuming a universal vulnerability–recovery relationship in infrastructure disasters and highlight the sensitivity of nighttime-light-based equity assessments to how recovery is operationally defined.