English
Čeština (Czech)
The paper presents an analysis of water quality data from the downstream part of the Czech Elbe and the Vltava for the period 1961–2020 and compares it with archive data (reference period 1880–1913). The transport of nitrogen and total phosphorus within the catchment was compared with the output from wastewater treatment plants (WWTPs).
Paper deals with the development of water quality of the river stretch of Elbe between the confluence Elbe/Vltava and the Hřensko/Schmilka on the frontier Czech Republic/Federal Republic of Germany in the period 1980–2020 and with the influence of Prague City on its pollution. After the significant improvement in the period 1985–2000, the quality of water discharged through the profile Hřensko generally complies with the German level at least. Assessment of the transport budgets shows that Vltava river contributes more to the system only as having higher water discharges. Prague City contributes to the pollution of Vltava and Elbe only by discharge of phosphorus, for the rest of common pollution items it functions only as a non-significant source.
Series of 16 fishponds was monitored as a part of a drainage basin of Hracholusky reservoir, which is subject of a recovery project. All the fishponds were eutrophic – hypertrophic due to wastewaters from villages and little cities (including overflows from sewers) and/or due to too intensive production of “hunters ducks” – the phenomenon that is rarely mentioned.
The inflow parts of eutrophic reservoirs typically exhibit exacerbated rates of primary production, with concomitant increase in organic matter sedimentation. Its microbial remineralization leads to the consumption of electron acceptors.
Based on existing phosphorus data series in the Slapy and Orlík reservoirs and their main tributaries, we reconstructed P inputs to the reservoirs from the catchment during 1961–2016 and compiled empirical models of P retention.