Berücksichtigung der Fließgeschwindigkeit bei Hochwasser-Schadensmodellen

Consideration of flow velocity in flood damage models.

Reliable prognoses of building damage caused by flood impact require realistic relationships between action and damage or loss describing parameters. Due to the fact that commonly applied damage functions are related to the different usage classes (i.e. private housing), the required differentiation according to the parameters on the resistance side is still missing and further impact parameters like flow velocity remain unconsidered.
On the basis of the August 2002 Saxony flood data base, a method to determine the structural damage for any given flood scenario was developed.
This method is improved to consider the correlation between inundation level and flow velocity and structural damage. The study is based on two different datasets collected after the flood 2002 in Saxony:
- Dataset 1 is related to the outcome of a questionnaire survey performed by the authors between 2002 and 2004.
- Dataset 2 is the outcome of an evaluation of damage expertises by order of the "Landestalsperrenverwaltung Sachsen".
A set of new Specific Vulnerability Functions (SVF) for calculation of damage grades is derived considering the inundation level and the flow velocity depending on the vulnerability of the predominant building types.
Based on new developed Specific Damage Functions (SDF) the calculated damage grades are transferred into loss estimates.
The developed tools are applied to the reinterpretation of the August 2002 flood damage. Results of the approach are presented for three different study areas in the free state of Saxony. In all cases a remarkable good agreement between the predicted and the reported loss can be stated.
First investigations with respect to the location of buildings, the direction of inflow and the structural damage are represented.