Hydraulic control on sedimentation processes and bottom sediments chemistry of Sulejów Reservoir in Poland

The Sulejów reservoir is one of the largest reservoirs in Poland and is exposed to a large flux of nutrients from both point and diffuse sources, which leads to an excessive amount of eutrophication and cyanobacteria bloom. The underlying inspiration for this paper was to use a 1D HEC-RAS hydrodynamic model to improve the knowledge of sedimentation conditions and the chemistry of bottom sediments in the context of reservoir eutrophication and algae bloom. Field sampling was performed, and chemical concentrations of Total Organic Carbon, Total Phosphorus, and Cadmium were measured in samples from bottom sediments. The deepest parts of the reservoir and the presence of sediment traps coincide with the highest concentrations of organic carbon, nutrients, and heavy metals. The paper has shown that reservoir hydrodynamic modelling and precise bathymetry maps provide very valuable information that can be used for the interpretation of bottom sediment chemistry patterns and for understanding the conditions of sedimentation.