A model to evaluate infrastructures vulnerability in case of forest fires in wildland-urban interfaces zones

The aim of this study was to develop a model for the evaluation of infrastructures vulnerability to forest fires in Wildland-Urban Interfaces (WUI), based on integrated environmental and operative data and measures. The model, based on GIS tools, gives indications on:-maps on infrastructures fire exposition classified considering their different vulnerability-significant factors influence in determining a specific vulnerability level The model considers, as input data: types of vegetation, numbers and related surfaces of historical fire events, slope and operational difficulties related to fire suppression (both for ground and aerial means of intervention). The present study evaluated variables connected to forest environment; however the model could be tuned to include data from different sectors (i.e. building characteristics and materials evaluation). The considered variables, giving indication on environmental risk aspects, are expression of apparently not comparable parameters (i.e. vegetation inflammability, water point road distance) and consequently expressed by different measurement units. To overcome this problem a Multi-Criteria Decision Analysis technique (Analytic Hierarchy Process-AHP) was used to compare cited data. The AHP is based on interviews with experts (operative room managers, firebosses, researchers) and is a statistical method both for relating subjective preferences of singles or groups of stakeholders within a decision-making process and for assigning a level of importance (weight) to each variable considered in the model. The final product is a map classifying the risk to wildfire for the buildings in WUI areas; it is useful for manager in planning prevention actions and during the attack phases in establishing priorities.