A comparative analysis of flood damage models: lessons learnt and future challenges

Flood damage assessment is crucial to address the challenges of climate and socioeconomic changes. Researchers and practitioners have developed several damage models to tackle local and regional situations. Particularly for direct damages to the residential sector, these models rely on numerous hypothesis (e.g. zero damage threshold) and parameters (e.g. recovery costs) assumed to fit specific local conditions and available data. Thus, transferability of damage models and reliability of observed losses have become key topics in the debate.This work aims at understanding the behaviour of different residential building damage models through their application to a case study in order to compare assumptions, estimated exposure values and losses. The research work is designed as a "blind" exercise where different research groups make a damage assessment starting from the same building dataset. Nine models are applied to estimate exposure and damage at the single-building scale. The results are compared in terms of exposure values, total damage and individual building damage. Although damage models differ in assumptions and parameters, the application highlights a good correlation among models in terms of exposure and relative damage, while correlation with monetary damage recorded in claims is low.