A new model for consideration of flow velocity in flood damage and loss prognosis

Abstract

Reliable prognoses of building damage caused by flood impact require realistic relationships between action and damage or loss describing parameters. A remarkable progress is reached with the EDAC flood damage model which takes into account the vulnerability of the different building types and allows the prediction of structural damage as a function of flow velocity and inundation level over the specific energy height. The paper discusses an extended method for the prognosis of structural damages and provides refined correlations between inundation level, moderate to high flow velocities in dependence of the vulnerability of the different building types and the number of stories of the building. For lower flow velocities, typical for river floods, the study is based on a comprehensive qualified damage dataset collected after the flood 2002 in Saxony. Due to the lack of reliable damage data caused by high flow velocities in flash flood events, an innovative approach is adopted to extend the damage database by including and reevaluating the damage data from the tsunami after the 2011 Tohoku earthquake in Japan. The developed tools are applied to the re-interpretation of the August 2002 flood damage. The calculated damage grades are transferred into loss statements. Results of the approach are presented for different study areas in the Free State of Saxony