Simulation of floodplains on rivers in urban areas

The paper presents the result of research on simulating the flooding of a flood on a stretch of river located in an urban area. The study area was located on the section of the Trotuș River that crosses the city of Comănești, Bacău County. The simulation was performed with the HecRas program for several scenarios differentiated by the value of the transit flows (Q1%, Q2%, Q5% și Q10%,). In order to apply the simulation program, it was necessary to carry out complex studies such as topographic, hydrological, hydraulic, how to equip the river with regularization works, the constructive characteristics of the works, etc. The presence of the riverbed regularization works modifies locally flood parameters and implicitly the parameters of the flood band. The simulation highlighted the positive, but also negative, cooperation of the arranged and unarranged river sectors with regularization works for the formation of the flood band. Also, the simulation highlighted the need to rehabilitate the existing regularization works, but also the need to carry out new works.