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Assessing the Possibility of Setting up a Dam
Prokešová, Eva ; Hlavinková, Vítězslava (referee) ; Hrubanová, Michaela (advisor)
The aim of the thesis is to assess the possibility of establishing a water reservoir in s selected location witch regard to its possible water management activities including geological conditions. The thesis also defines basic terms related to water reservoir and their parts. This work was elaborated with the help of available literature and valid laws of the Czech Republic concerning the given issue. At the end of the work will be valued land meeting the conditions for the construction of a small water tank. The award will take place in two ways according to the decree and direct comparison.
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Jakost vody vybraných rybníků v povodí toku Vydrica
Krajči, Filip
The diploma thesis is focused on the assessment of water quality in two successive ponds located on the Vydrica stream in the Malé Karpaty mountains. The analysis and subsequent assessment of water quality is based on field monitoring associated with the collection of samples and their subsequent analysis in the laboratory. The literary research deals with the assessment of water quality, the distribution of water, the distribution of protected landscape areas, but also the methods of management of ponds and the susitability of given ponds from the point of view of fish breeding. The literature review also contains a description of field monitoring indicators and laboratory determinations. The methodological part describes the principles of establishing field research and analysis of monitored water samples in the laboratory and the characteristics of sampling sites. The results obtained by field measurements and subsequent laboratory analysis were evaluated based on STN 75 7221 and Government Regulation No. 269/2010 Coll. After the evaluation, it was found that the water achieved the worst results, especially in the field of indicators reflecting organic pollution (BOD5, CHSKcr). Also, the content of elements such as total nitrogen and total phosphorus reached levels exceeding the limits of the worst class. These facts can further help in the management of the designated areas or in revitalization works in the vicinity, which are planned in the near future.
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Horizontální proudění vody v malých rybnících
ŠŤASTNÁ, Tereza
This bachelor thesis dealt with the flow in small ponds (specifically in pond Dehtář near the village Žabovřesky) with a focus on horizontal flow. Its aim was to perform field measurements of water movement of the surface (using devices developed by us, equipped with GPS logger) under various atmospheric conditions and from the results to determine the water flow velocity at the surface in real conditions. GPSMAP 78s, GPSMAP 60CSx and MOTOROLA phones with GPS Logger application inserted into balanced PVC pipes were used for measurements. Another objective was to create a simplified 3D model of the pond and simulate the flow in its deeper layers using Ansys software. Field measurements resulted in streamlines showing the direction of flow for the top layer of water. With wind speeds of 1-3 ms-1 in foggy and cloudy weather, the observed flow velocity was approximately 0.025 ms-1. At very low wind speeds of 0-1 ms-1 in foggy weather, the flow velocity was 0.0083 ms-1. Under variable conditions, when the surface was first slightly frozen but then melted and stronger winds from a different direction began to blow, the resulting flow velocity was first 0.025 ms-1 (at a wind speed of 0.7-1 ms-1) and later 0.0375 ms-1 (at a wind speed of 2-3 ms-1). The Ansys modelling resulted in simulations of flows in simplified ponds of two shapes (one with a sloping bottom, 0.5-4 m depth and rounded corners and the other with a constant depth of 2 m and a depression with a total depth of 4 m and rounded three corners) at different wind velocities (0.5; 1; 2; 4; 8 and 16 ms-1) and three or four wind directions. In general, the simulations showed that the flow velocity increased with wind speed, with the prevailing flow velocity being about 3% of the wind speed for all simulations. At the same time, flow velocity decreased with depth, and water was mixed to approximately 95% of the depth (up to 3.8 m). The simulations also showed the formation of eddies, here the water moved fastest where the eddies touched the edge of the pond, but in the centre of the eddies there were often areas of very low flow velocities and relatively long residence times (from seven hours to six days). The results of the field measurements and simulations in this thesis can contribute to the understanding of the processes (e.g. the effect of water mixing on oxygen, plankton and nutrient content at different areas) occurring in pond Dehtář. They may thus provide a basis for subsequent mapping of its circulation patterns, which may influence the origin and development of oxygen deficiencies and the concentration of natural food for fish and nutrients in certain parts of the pond. They can thus help to determine the suitability of areas, for example for fish feeding or sampling and thus have a positive impact on improving the management of this pond.
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Nutrient balance of the Rožmberk pond and its influence on the water quality of the Lužnice river
MONDEKOVÁ, Aneta
This diploma thesis deals with the nutrient balance of the Rožmberk pond for the years 2020-2021 and its impact on the river Lužnice. Due to the strongly eutrophic state of the pond caused by several polluting influences, such as insufficiently treated wastewater from the Třeboň WWTP or the outlet of wastewater from the R.A.B large pig farm, the Rožmberk pond was evaluated as the main source of phosphorus for the Orlík. The river Lužnice, flowing through Rožmberk, transports nutrient-rich water further to Orlík. Furthermore, this work is devoted to the study of sediments and phosphorus contained in it, as an internal source of phosphorus in the pond. The aim of this diploma thesis is to evaluate the nutrient balance for the mentioned years and compare with previous years of balance monitoring to the current situation in Rožmberk. The last calculation of the substance balance was in 2014, and therefore it is important to find out what the current situation on the pond is. Data for the purposes of this work were obtained by regular, balance monitoring of the state enterprise Vltava River Basin within 14-day intervals. Based on the results obtained by this work, when the pond showed negative retention, i.e., more phosphorus flowed out than it reached the pond with tributaries, it can be stated that the Rožmberk pond is a significant player influencing water quality in the Lužnice river basin. Internal processes are applied in the pond, when the pond copes with the old ecological burden, due to the significant amount of phosphorus stored in the sediment. Rožmberk pond shows that material balances are indispensable for determining the actual conditions in ponds. We cannot do without this information about the proposed measures to improve the quality of water in ponds.
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Zlepšení kvality vody při výlovech rybníků pomocí flokulantů
MONDEKOVÁ, Aneta
This bachelor thesis deals with the possibility of improving water quality, that is discharged during fish harvest. The aim of this bachelor thesis was to capture undissolved substances and nutrients in the discharged water in the sewer under the pond by a system of two barriers made of organic material. The barriers served to raise the water level, which provided the time needed for the particles to sediment. Sedimentation was enhanced by flocculant dosing. The evaluation was performed based on a comparison of water quality on profile A without the addition of flocculant and profile B with the flocculant already contained. The difference showed the efficiency of trapping undissolved substances and nutrients by the barrier. Based on the results, it can be stated that barriers made of organic material are able to improve the quality of water discharged from ponds.
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Současný stav kvality vody v rybnících
BENEDIKT, Adam
Monitoring the quality of water in a pond in connection with fisheries management did not begin to gain importance until the end of the 20th century. Since then, numerous studies have been conducted on this topic. Currently, the most significant problem affecting not only the fishing companies is the eutrophication and its impact on the function of a pond and the surrounding landscape (including biodiversity and the overall impact of eutrophication on the environment). Anthropogenic activity (e.g., fish farming, wastewater, and agriculture) leads to an excessive release of mineral nutrients, predominately phosphorus and nitrogen, into open waters. This bachelor thesis compares the data obtained from measurements from the year 2017 with data from the 1950s. until 2014 as documented in the written records. The actual data represent the basic physicochemical parameters of water (i.e., temperature, O2 concentration, pH, conductivity and ORP, TN, NH4-N, NO3-N, TP, DRP, TOC, and chlorophyll-a). The evaluation is based on a collection of data from six ponds in the vicinity of České Budějovice (Beranov, Roubíček, Zběhov, Posměch, Kvítkovice, and Dehtář) with a representation of production and fry tanks.
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The effect of sampling point on hygienically significant water indicators in natural bathing establishment
Zelinková, Myra ; Benešová, Libuše (advisor) ; Popovský, Jiří (referee)
In this diploma thesis, I deal with the influence of the sampling site on water quality in natural bathing lakes (Hostivar reservoir, Seberak pond and Vyzlovka pond) in this. I have established that hygienically significant kinds of phytoplankton may differ in terms of water quality especially where there are cyanobacteria constituting water bloom. Surface water bloom may be moved by wind to the lee side of the water body (Microcystis sp.). Aphanizomenon flos-aquae water bloom floating in water column can be affected by wind and by water flow (which may be partly affected by wind as well). With the prevailing fibrous Planktothrix agardhii which does not connstitute water bloom the concentration of chlorophyll-a and cyanobacterial cell abundance in individual sampling sites are similar although the concentration of chlorophyll-a a is about 200 g.l-1 . Microcystis sp. and Scenedesmus sp. survive under eutrophic conditions in competition. From the microbiological perspective, water quality can differ within a single sampling site in places at a distance of less than 100 m. Microbial contamination can be caused by bathers, water birds, farm animals and probably by the removing of microorganisms from sand, mud and sediments on the beach or shore. Rain episodes probably increase the abundance of E.coli...
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Revitalization of the Small Water Reservoir in the Skalička u Hranic Cadastral Area
Majkus, Martin ; Havlíček, Tomáš (referee) ; Paseka, Stanislav (advisor)
The aim of this paper is to propose a comprehensive revitalization of the side pond in the cadastral area of Skalička. As part of revitalization measures, the removal of mud from the pond, fortification of the banks and other modifications in connection with functional structures are proposed. In order to take water into the pond, a concrete diversion structure in the Hlubocky stream bed is designed, connected with pond via open canal with 2 pools, which will substitute the existing supply pipeline. As part of stabilization of the streambed and to overcome height difference, a boulder chute with stilling basin and related modifications are designed. The introductory part is a summary of knowledge from the issue and it explains important terms, historical context and description of basic principles. The next part describes the current situation and conditions in the surveyed locality. The following is a description of the methods and programs that were used for this work. The design part presents the proposed revitalization measures. An essential part of the work is also the varification of the proposed modification in the streambed, using 3D digital terrain model in Atlas DMT and subsequent 1D flow simulation in HEC-RAS.
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