Comment to REFEREE 1 Interactive comment on “ Enhancement of large-scale flood damage assessments using building-material-based vulnerability curves for an object-based approach ”

Abstract

In this study, we developed an enhanced approach for large-scale flood damage and risk assessments that uses 10 characteristics of buildings and the built environment as object-based information to represent exposure and vulnerability to flooding. Most current large-scale assessments use an aggregated land-use category to represent the exposure, treating all exposed elements the same. For large areas where previously only coarse information existed such as in Africa, more detailed exposure data is are becoming available. For our approach, a direct relation between the construction type and building material of the exposed elements is used to develop vulnerability curves. We further present a method to 15 differentiate flood risk in urban and rural areas based on characteristics of the built environment. We applied the model to Ethiopia, and found that rural flood risk accounts for about 22% of simulated damages; rural damages are is generally neglected in the typical land-use-based damage models particularly at this scale. Our approach is particularly interesting for studies in areas where there is a large variation in construction types in the building stock, such as developing countries. It also enables comparison across different natural hazard types that also use material-based vulnerability, paving the way to 20 the enhancement of multi-risk assessments.