Procjena poplavnog rizika s utjecajem nesigurnosti

Many river basins are experiencing frequent flooding events with significant economic and other losses due to intensive precipitation as well as other atmospheric and hydrological conditions. European Flood Directive defined flood risk as a combination of flooding probability and possible adverse consequences on people, assets, cultural heritage and environment. Flood risk management considers implementation of different measures for mitigation and prevention of possible negative consequences related to flooding. Uncertainty can strongly affect the flood risk management process, especially near and during the flood event. A framework is proposed for implementation of uncertainty related to behavior of the endangered system in the flood risk assessment, in order to improve the decision-making process during the flood emergency response. The proposed framework is validated on the City of Slavonski Brod pilot site, where the results demonstrated that there is a significant flood hazard still present due to possible weir failure, despite the improvement of flood defense measures. Furthermore, the results demonstrated how flood risk value can significantly decrease by properly evacuating the affected population. Flood risk management on a strategic level requires a monetary quantification of possible flood risk, which is performed by calculating expected annual damage (EAD) based on the combination of flooding event probability and corresponding damages. A semi-analytic methodology is presented for estimation of expected annual damage based on the factor graph model, which enables integration of entire probability space as well as flexibility in defining input data. Furthermore, a novel approach is presented for definition of annual damage distribution based on first and second statistical moment and by employing Beta distribution. By analyzing the annual damage distribution as well as impact of different sources of uncertainty, the results demonstrated that there is a significant impact of extreme events with low occurrence probability on the expected annual damage.