Relationships between building features and wildfire damage in California, USA and Pedrógão Grande, Portugal

Background Buildings in communities near wildlands, the wildland–urban interface (WUI), can experience wildfire damage. Aims To quantitatively assess relationship between building features and damage, a resistance index is developed validated with 2013–2017 CAL FIRE (DINS) database from California, USA, 2017 Pedrógão Grande Fire Complex post-fire investigation Portugal. Methods Three statistical dependence tests are compared to evaluate selected The Wildfire Resistance Index (WRI), range: [–1, 1], proposed as rating for susceptibility. Key results most correlated damage presence of vent screens deck materials exterior walls material For Portugal, WRI increases by 50%, linear regression estimates 48% decrease proportion highly damaged buildings, 42% increase low buildings (R2 0.93 0.90, respectively). A total 65% California = 1 were destroyed, average 85% ≥−0.33. Conclusions quantifies experienced two diverse WUI regions. Implications could be used an estimator but it needs further development.