Assessment of sediment and nutrient sources and their influence on eutrophication: case study from the Czech Republic

The purpose of a three-year project QK22020179 is to build a methodology to assess the importance of the impact of sediments deposited in the tributary parts of reservoirs on water quality. The project should describe the dynamics of phosphorus release or capture in sediments in relation not only to the environment of the reservoir, but also to the source basin, the mineralogical composition of the sediment, its granularity and chemistry, and the method of its supply to the reservoirs.

In 2022, the solution was concentrated in the catchment areas of the Bojkovice, Boskovice, Hamry, Seč, Stanovice and Lučina reservoirs. Sediment traps were installed in the inflow reservoirs, continuous models of sediment transport from the catchment were also compiled for the reservoirs, and key parts of the catchment area were defined as potential main sources of sediment. By analyzing the mineralogy and chemistry of the listed source areas, especially on the basis of data from agrochemical analysis of agricultural soils, potential links are now being created between the sediment properties in the inlet parts of the reservoirs and the source areas defined by the model.

The paper will present the current results and the overall methodology with the aim of obtaining feedback in the discussion, because the methodology of potential "fingerprinting" of sediment in catchments and defining the importance of its properties for the behavior of reservoirs in terms of eutrophication has not yet been developed in the Czech Republic, let alone successfully solved.

Research has been supported by projects QK22020179 and SS03010332.