Employing different hydrodynamic models (MIKE & HEC-RAC) to predict the extreme flood in the Hron River, Slovakia and provide the adequate mitigation measures

Expectations for a change in precipitation patterns due to climate change effects make floods one of the main concerns of water authorities. The minimization of the negative effects of floods for a particular region depends on the success of hydrologic and hydrodynamic modeling approaches. In this study, the abilities of two of the most popular flood modeling software, namely, HEC-RAS and MIKE+, were used for flood modeling in the Hron River in Slovakia. For modeling purposes, various discharge values of the River from one year to hundred years peak discharge were considered. The vulnerability of the catchment for each period was modeled and visualized using both software. The HEC-RAS and MIKE + outputs showed that the study area is vulnerable to flood for high-frequency peak discharge values. The outputs of both 2D hydrodynamic approaches were found to be close to each other in various flow conditions. The comparisons of the MIKE + and HEC-RAS showed that Hron River dimensions for the given catchment are only sufficient to transfer a one-year peak discharge value safely. The outputs of the models exhibited that the study area is not safe in case of ten-year peak discharge value and the risk of the floods getting the highest level in case of hundred-year peak discharge. Due to the models’ findings, it is seen that the area is vulnerable to flood, and three different mitigation scenarios were proposed and analyzed including change in river bed dimensions and rise of the levee on the right and left river bank to protect the area from flood risks. After applying these scenarios, the whole area around the river for length of five kilometers is protected from flood risks. The mitigation measures and the proposed scenarios can have significant effects on saving lives and protecting the properties, industrial areas and agricultural lands.