Three-dimensional numerical modeling of water temperature distribution in the Rozgrund Reservoir, Slovakia

The Rozgrund water reservoir is one of the oldest reservoirs of the water supply system in the vicinity of Banská Štiavnica. In the past, it was one of the important reservoirs supplying the population with drinking water. Knowing the spatial and temporal variations of water temperature in the reservoir is the primary step to investigate and model water quality. Therefore, the present study was planned to simulate water temperature distribution in the Rozgrund Reservoir by incorporating atmospheric and bathymetric conditions using MIKE 3 FM model and took a step forward to model extreme hydrological and meteorological events impacts. The simulations were performed for July 2022 and the model provided 3D visualization of water temperature variations and corresponding temporal differences during the entire simulated period. The results revealed that the Rozgrund Reservoir experienced temperature stratification (i.e. non-isothermal layers) in the period of simulation when the initial temperature was given to the model, while the constant initial temperature condition needs a long time to reproduce water temperature stratification. In addition, this study assessed the impacts of high inflows on patterns of current flows and water temperature throughout the Rozgrund Reservoir. The present work has implications for improving the understanding of changes in water temperature distribution in the Rozgrund Reservoir and similar reservoirs and supports further works, as well.