Flood Depth-Damage Functions for Built Environment

A conventional approach for the economic estimation of direct flood damage to buildings is using the method of depth-damage functions. However, there are few publications that describe in detail the derivation of depth-damage functions based on actual flood damage data. It still remains an open issue whether a site-specific depth-damage function can be applied to another region with similar climate and building conditions. This paper aims at demonstrating a step-by-step methodology for devising depth-damage functions using data from a flood event which occurred in Moschato, a suburb of Athens, Greece in July 2002. It also compares the developed depth-damage functions to functions from other areas with similar conditions. In the case study, the damage percentage is calculated per category of flood-affected property on the basis of relief payments. The replacement cost of the affected components of a building structure and the market value of each category of flood-affected property are estimated in order to develop depth-damage relationships for building structures. The local depth-damage function for residential use is compared to generalized functions and a site-specific function developed for the urban area of Palermo, Italy. Differences and similarities in damage datasets are examined and explained by related causative factors such as structural or architectural features of buildings. Finally, the application of both of the above functions to a third case (the Erasinos river basin in Attica, Greece) resulted in a fair difference (9 %) in the estimation of the expected average annual direct damage to residential buildings. © 2014 Springer International Publishing Switzerland.