Modeling building use helps estimate regional damage

Christoph Aubrecht of the Austrian Institute of Technology in Environmental Research Web: Increasing demand for land, particularly in mountainous regions, leads to further expansion of settlements into known hazard-prone areas. The potential impacts, as well as regionally defined levels of "acceptable risk", are often not communicated and are also difficult for the public to understand. Analysing past events and assessing regional damage can help planners on all levels to improve sustainable risk management.

In this study we used a geospatial and statistical approach to assess damage costs for a certain region. We included information about actual conditions in terms of land-use disparities and damage data from a documented severe flooding event. First, we classified buildings according to their function and use. To derive functional land-use patterns at very high spatial resolution we linked company information to the building model via geocoded postal address data, which enabled us to classify building types in terms of their predominant use.

To assess the impact, the flood plain is delineated according to post-disaster aerial imagery and a digital terrain model that distinguishes between areas that are subject to long- and short-term flooding. Four regional-damage cost-assessment scenarios with different levels of detail are also calculated, with the most elaborate including high-level land-use information and distinguishing short- and long-term flooded areas. Projecting damage costs relies on sample building-level damage records – from the severe 2005 flood in Austria‘s western province of Vorarlberg – that allow for approximate damage averaging for distinct buildings. The results confirm that taking local land-use patterns into account is essential for optimizing regional-damage cost projections.....

A big 2005 flood in Austria threatened the Brixentaler bridge, public domain