A high-resolution compound vulnerability function for European winter storm losses

Economic losses from European winter storms impose a significant burden on society and are increasing due to exposure growth and climate change. Vulnerability functions play a key role in estimating such losses by describing the relationship between a natural hazard’s intensity and damage to the exposed asset. We provide a vulnerability function for residential buildings which, for the first time, can account for winter storm damage from both wind and precipitation. This compound vulnerability function is estimated using truncated beta regressions and is based on residence-level insurance claims and ultra-high-resolution meteorological observations. Comparing our vulnerability function to the conventional specification, which only considers damage from wind, shows that the latter underestimates the damage by 5% [21%] {57%} for winter storms with 24-hour cumulative precipitation levels of 50 mm [75 mm] {100 mm}. Hence, as European winter storms become wetter, compound vulnerability functions are required to accurately estimate their damage.