Flood Risk Monitoring by Using 2D Hydrodynamic Modeling: A Case Study of Frýdek-Místek City

Flood monitoring by optimal and cost-effective solutions is among the most important challenges facing cities. This paper focuses on creating a 2D hydrodynamic model that is accurate enough for generating information about possible flood zones within urbanized areas. The complex urban area of Frýdek-Místek city was selected as a case study to simulate the extreme flood event which occurred in May 2010 (16.5 - 24.5). The model is based on high-resolution topographic data with spatial resolution of 1,4 m. The study used the new HEC-RAS ver.5 model developed by the U.S. Army Corps of Engineers for 2D flood simulations within the city. The simulations were performed on a 4 km reach of the Ostravice River. Overall, the inundated areas and the maximum water level were consistent with real measurements, and therefore we can claim that our 2D hydraulic model is realistically able to simulate water behaviour in highly urbanized areas. The average error in elevations was 10 cm (at the Frýdek-Místek water station) and the inundation area was overestimated by 9.7 % in the city park.