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Hodnocení rybářského využití koupacích vod v povodí řeky Moravy s ohledem na možné interakce s vývojem kvality vody
Adámek, Zdeněk ; Jurajda, Pavel
The evaluation of possible relationship between fisheries management and water quality in bathing sites in the Morava River catchment area, as presented on public web pages www.koupacivody. cz, was performed on an example of 24 evaluated waterbodies. On the sites, which belong to the angling grounds, an obvious relationship between the proportion of predatory fish biomass in fish yields (F/C index) and bathing quality of appropriate sites was recorded. Mean F/C values in fish catches, as the most appropriate criterion, amounted to 17.8 and 21.5 in bathing suitable water and bathing suitable water with deteriorated sensory properties, \nrespectively. It seems apparent that the bathing water quality reflects in certain extent the principal characteristics of fisheries management. In carp farming ponds, incorporated legally among bathing sites, this tendency was not so obvious and it seems that not even the intensity of supplementary feeding was the main reason limiting the suitability for bathing.
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Erosion of agricultural land and its importance for siltation and eutrophication of reservoirs in the Czech Republic
Krása, J. ; Jáchymová, B. ; Bauer, M. ; Dostál, T. ; Rosendorf, P. ; Hejzlar, Josef ; Borovec, Jakub ; Bečička, M.
In 58 large catchments of the Czech Republic (covering ca 35000 km2) the sediment transport processes were assessed. Amount of sediment flux into the streams and reservoirs from agricultural land was estimated. Sediment retention in all reservoirs was considered based on reservoirs‘ outflow. For thousands of small ponds the volumes and outflow had to be estimated based on reservoir areas and specific flow rates in catchments. The distributed approach allowed considering importance of particular agricultural fields for stream silting. The maps of annual sediment flow in all streams were derived. The sediment fluxes cause serious problems not only concerning eutrophication. For example Vltava river watershed up to Slapy dam (12 965 km2) exports 2.34 million tons of sediment by water erosion annually. 626 thousand ton is exported into the streams, and 615 500 t is then deposited in the reservoirs.
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Management of reservoir sediments, sediment washing and reuse
Vrzák, J. ; Knotek, J. ; Borovec, Jakub ; Dadejík, M. ; Krist, P.
This article is primarily intended to introduce to the expert public, especially the operators of waterworks, the new procedures for the management of sediments in water reservoirs. These include the identification of sediments, their localization, extraction, and transformation, as well as options for the sediment washing and their possible subsequent use. Presented techniques aim to find an economically feasible management solution for reservoirs affected by deteriorated water quality - cyanobacteria./nIn the years 2012 – 2014, a research project entitled “VVIF/nResearch of washing processes in dam sediments” has been conducted. One of the objectives of the project was to find suitable methods for locating the dam sediment, sampling and identification of its material composition, which is an essential prerequisite for the selection of environmentally friendly and economically efficient processes and procedures, from preparation/nto implementation of the project. Another of the key objectives was the design and test of the process of sediment washing into primary components, with/nthe option of their reuse, or the transformation process of the whole sediment inside or outside of the reservoir.
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What can we say about sediments, evaluation of reservoir sediments and their link to eutrophication
Jan, Jiří ; Borovec, Jakub ; Hubáček, Tomáš
This work is focused on a detailed sediment evaluation and potential sediment impact on the eutrophication of reservoirs. Two methods for this purpose are presented: i) fractionation for sediment particles characterization and ii) an application of gel minipeepers (DET probes) for sediment pore water sampling. By combining these methods we are able to determine the potential of P release from selected sediment. Examples of using/nthis approach on various sediment types are given to highlight the importance of determining not only the concentrations of total P in the sediment, but also, especially, the following: i) P concentrations in different forms, ii) concentrations of main binding partners for P in noncalcareous sediments – Fe and Al (hydr)oxides, iii) concentrations of dissolved P and Fe in sediment pore water, iv) concentrations of ions influencing redox/nconditions (NO3-) both in the water above the sediment and especially in the sediment pore water.
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Fishpond sediment – new approach to the nutrient recycling in the agricultural landscape
Potužák, Jan ; Duras, J. ; Kröpfelová, L. ; Šulcová, J. ; Chmelová, I. ; Benedová, Z. ; Svoboda, T. ; Novotný, O.
Possibilities of the use of the fishpond sediment in the improvement of arable land is discussed. Among others, this approach has a high potential to contribute to the recycling of phosphorus in the agriculture landscapes. For this purpose, we propose set of particular techniques which were tested in the field study.
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