The knowledge of return periods of floods is a prerequisite for flood hazard estimation. This is limited by short instrumental data series. Thus, the overall aim of FloodRisk-7000 is to improve the estimations on flood damage potentials by making use of and merging different kinds of data sets, including amongst others damage data, pre-instrumental paleoflood records and cyclone tracks.
Although damage data is in principle the kind of data most suitable to estimate flood damage potentials, it exhibits a crucial cutback: its availability is usually limited to rather short time horizons (i.e. a few decades in the best case), which causes high uncertainties in estimating the damage potential of these low-probability high-impact events. Hence, the idea of FloodRisk-7000 is to make use of paleoflood records derived from lake sediments to gain additional insights into the (past) distribution of flood events and thus improve estimations on (current) flood damage potentials. Moreover, by comparing flood events derived from sediment records and advanced meteorological circulation patterns, atmospheric patterns leading to major sediment loads can be identified and investigated under future climate change conditions. Using the identified atmospheric patterns and related heavy precipitation events as proxy for the occurrence of floods thus allows for the assessment of the future damage potential as well.
From a geographical point of view, the analyses carried out within FloodRisk-7000 will mainly focus on the northern part of Austria. The sediments of Lakel Mondsee – located in Upper Austria at the frontier to Salzburg – provide an exceptional spring/summer flood frequency record of the last 7000 years. Large scale precipitation at Lake Mondsee is located in the Alpine Northern Stau, which is particularly affected by Vb-type cyclones as well as by Atlantic cyclones as known from observation.