Author(s): Nino Krvavica; Bojana Horvat; Igor Ruzic; Andrea Tadic; Vlatko Roland; Ante Siljeg; Ivan Maric; Silvija Siljeg; Fran Domazetovic; Lovre Pana‘A; Rina Milosevic; Rajko Marinovic

Linked Author(s): Silvija Šiljeg, Nino Krvavica

Keywords: Pluvial floods; Flood hazard; Flood risk; Flood mapping; Hydrological-hydraulic model

Abstract: This study presents our experience with pluvial flood modelling and risk assessment in Croatia. We focus on the methodology that is suitable for investigating different levels of flood risk - from the catchment level to the city level to the local sub-basin level. We discuss the availability and selection of spatial input data, such as digital terrain models (DTMs) and land use models, and how they can be processed for flood hazard analysis and flood risk assessments. We highlight the differences between flood simulation results using DTMs at different resolutions and discuss the optimal resolution. We also examine different types of open land cover/land use data available for the EU, such as the Copernicus Land Monitoring Service data. We describe various aspects related to integrated 2D hydrological-hydraulic modelling and the rain-on-grid approach, and we compare the results at different scales. In terms of flood risk assessment, we explain two different types of analyses, particularly the differences between the object-based and the pixel-based approach. Lastly, we provide flood hazard and flood risk maps for a pilot area in Croatia and offer some recommendations for further research. Our study emphasizes the importance of using an integrated and comprehensive approach that considers different sources of flooding, as well as the potential compound effects of these sources, to develop more realistic and accurate flood risk assessments.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0803-cd

Year: 2023