Strengthening tropical cyclones are associated with more frequent hazardous material pipeline failures in the Eastern US

Elizabeth Carter, Marilyn Smith

Over 30,000 hazardous material pipeline (HMP) failures have caused nearly $11 billion in damages since 1970. Tropical cyclones, which cause more infrastructure damage than all other forms of natural disasters combined, are under-reported causes of HMP failures, largely due to historic policy around pipeline failure reporting. This study defines tropical cyclone-associated HMP failure frequency  based on spatiotemporal concomitance while detrending for background HMP failure rates. The relationship between the likelihood and frequency of HMP failures and tropical cyclone intensity is characterized. Since 1975, the annual frequency of tropical cyclone-associated pipeline failures has increased by an order of magnitude. Storm intensity is significantly related to the frequency of HMP failures, explaining 32% of spatial variability and 38% of inter-annual variability in local storm-level pipeline failure frequency. Since 1970, the average annual maximum tropical cyclone intersecting with HMP infrastructure has increased from a Category 3 to a Category 4 storm on the Saffir-Simpson hurricane scale. Assuming near-term conservation of historical meteorological trends, 200-500% increases in the number of pipeline failures occurring during the annual average maximum tropical cyclone are projected across the Eastern US by 2050. Implications of accurate natural hazards-related cause attribution on HMP failure incident reports are discussed.