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Evaluation of runoff formation in catchment using stable isotopes 2H and 18O and water temperature
Hojovec, Daniel ; Vlček, Lukáš (advisor) ; Jeníček, Michal (referee)
The evaluation of the water regime of the springs, or the total runoff in small mountain catchments, is an important aspect in this work for understanding the functioning of the catchment from the point of view of the precipitation-runoff process, and above all for the verification or refutation of the various methods used to evaluate the runoff of the mountain catchment. For the stated purposes, between 2018 and 2020, repeated sampling was carried out from water courses, soil (shallow wells) and precipitation in the Rokytka catchment area. From the obtained data, the ratio of stable isotopes 2 H and 18 O was subsequently determined in the laboratory. We also worked with the data of stable isotopes 2H and 18O provided by the Department of Physical Geography and Geoecology of the Faculty of Natural Sciences of Charles University for the period 2014-2018. All data, together with hydro-meteorological data, were subjected to various analyzes and methods with the aim of evaluating the runoff. The core method of this work was hydrogram separation using a mixing equation working with stable 2 H isotopes and water temperature for 6 events. On the basis of the performed analyzes and hydrographic separations, it was found that the water in the Rokytka přítok during significant rainfall-runoff events is...
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Spray Cooling at High Temperatures
Chabičovský, Martin ; Čarnogurská, Mária (referee) ; Hajduk, Daniel (referee) ; Raudenský, Miroslav (advisor)
Spray cooling of hot surfaces is used in the metallurgical industry during continuous casting, hot rolling or heat treatment. The water is sprayed on the cooled surface by the nozzle which transforms the water stream to droplets. The spray cooling of hot surfaces can be characterized as forced convection with the presence of the boiling. This physically complicated process is influenced by many factors, such as impurities and contaminants in the water, water temperature, water flow rate, droplet size, droplet impact velocity, surface temperature, surface roughness or the presence of oxides (scales) on the cooled surface. The dominant factor that affects the heat transfer during the spray cooling is the water impingement density. Other factors have a smaller but also significant effect. This doctoral thesis deals with the influence of the water temperature, surface roughness and the presence of oxides on the intensity of the spray cooling. These factors are investigated by laboratory experiments in which the hot steel surface is spray cooled. Effect of the oxide layer is also investigated by the numerical simulation. The experimental results are theoretically explained and generalized using mathematical methods.
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Natural Swimming Pool for a Small Municipality
Mrkývka, Michal ; Hyánková, Eva (referee) ; Kriška-Dunajský, Michal (advisor)
Bachelor thesis deal with natural swimming biotope. In the first part concetrates on the principle of water purification natural swimming pool, a device used for the operation, properties of water, right sort of plant and regulations dictated by the state. In the sekond part presents free selected natural swimming pool in southern Moravia, compares selected indicators in bathing water and source water in natural biotope. At first depots graphic progres sof temperature, transparency and pollution in a particular biotope and then compares individual biotope between them with respect to the notice of the Ministry of Health.
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Three-way control valve in industrial environment
Vozár, Viliam ; Čožík, Ondřej (referee) ; Levek, Vladimír (advisor)
This work deals with the design, realization and testing of the system for regulating the temperature of the water in an industrial environment using three-way mixing valve. This system can work autonomously, but also can be controlled by a superior control system. Created temperature regulation can be adjusted and controlled by a computer using control software.
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Zhodnocení přežívání a růstu dvou invazivních raků v teplotně suboptimálních podmínkách
MARKOVÁ, Kateřina
Biological invasions of non-native species are one of the most serious threats negatively impairing global biodiversity. The negative influence of these invasions is especially noticeable in freshwater ecosystems also exemplified by the populations of native crayfish species in Europe. Dominance of non-native species of crayfish over native ones is relatively well known and studied, but the interactions between individual non-native invasive species are significantly less explored. As the range expansion and numbers of non-native crayfish species constantly increases, it becomes apparent that the non-native species will dominate in European waters. However, it is not clear which of these invasive species, and under which conditions will perform better. The goal of this bachelor thesis was to create a literature review focusing on factors that negatively influence the population of the native species (mainly the issue of non-native species and crayfish plague which these species often transmit). Consideration was paid to the importance of the water temperature for the crayfish and to the focused species used in the experimental part the marbled crayfish Procambarus virginalis Lyko, 2017 and signal crayfish Pacifastacus leniusculus Dana, 1852. The experiment was focused on the evaluation of survival, growth, damage to the claws, and the maturation of these species at the water temperature of ~16 °C, which is in the optimal range for signal crayfish, but suboptimal for marbled crayfish (yet, within a range presumably allowing its successful reproduction). If these species should meet more frequently in the wild, it is important to understand their relationships.
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Changes of selected surface water geochemistry parameters in relation to rainfall-runoff regime
Bartůšek, Adam ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
This work deals with the study of changes in the geochemistry of surface waters in relation to the rainfall-runoff regime and its transformation. As rainfall-runoff extremes such as long episodes of drought with low flows or, conversely, high flows caused by extreme rainfall events have been increasing in recent years, it is important to understand how these phenomena affect water quality. Therefore, the main objectives of this work are firstly a literature search on the changes in surface water geochemistry during change of climate and precipitation-runoff regime and methods that can be used to quantify these changes, and then the application of some of these methods to the analysis of selected parameters and their changes in the Klíčava catchment. In addition to some climatic characteristics and flow rates, the analysis included basic parameters of geochemistry (flow rate, water temperature), physicochemical parameters (electrolytic conductivity, pH), some nutrients (forms of nitrogen and phosporus) and indicators of organic pollution and stream cleanliness (BOD5, CODCr, TOC and dissolved oxygen). In addition, the status and evolution of concentrations of some herbicide metabolites were briefly assessed. For data analysis, e.g. box plots, Mann-Kendall test, correlation coefficients or linear...
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Changes of geochemistry of surface water in selected catchments of the Ore Mountains
Navrátilová, Denisa ; Matoušková, Milada (advisor) ; Benešová, Libuše (referee)
This master thesis focuses on an analysis of surface water chemistry, long-term trends and the impact of drought on changes in concentrations of selected parameters in the upper Svatava, Rolava and Načetínský potok basins located in the Ore Mountains. Research on water quality in mountain spring areas is important, the consequences of various changes can be easily observed there. This work analyses the changes in surface water chemistry and discusses their possible causes, especially the impact of peat bogs and dry episodes. The parameters of water temperature, conductivity, pH, BOD5, COD, TOC, concentration of nitrate nitrogen, total phosphorus, phosphates, sodium, potassium, calcium and iron were investigated for the period 1993-2018. The available data are analysed using evaluation methods according to ČSN 75 7221 as well as box plots, Pearson correlation coefficient, PCA analysis and Mann-Kendall test. The greatest anthropogenic influence exhibited in Svatava, almost all concentrations reached their highest values there. In the Rolava and Načetínský potok basins, the influence of peatlands manifested itself by increasing the concentrations of iron, TOC and COD. The results of trends showed an increase both in pH and in surface water temperature related to an increase in air temperature, on the...
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Physiochemical Parameters of Ponds during Hydrological Year
HUMMELOVÁ, Světlana
Physiochemical Parameters of Ponds during Hydrological Year The aim of this Bachelor thesis was to use the obtained data for the assessment of these physiochemical parameters on growth of the carp. The obtained data and their influence on carp grow were compared with literature. The physiochemical parameters had measured on the 29th June, 16th July, 12th August and 4th October on the Dehtář pond. The followed physiochemical parameters were measured: concentration of oxygen (mg-l-1), temperature of water (°C), pH, transparency (m) and chlorophyll concentration (?g-l-1). It was used calibrated measuring device EXO2 and a Secchi disc. The pond was measured in two transects with focus on depth, inflow, outflow and feeding area. For better evaluation of the results it had included the continuous measurements data from Vltava River Authority, particularly the concentration of oxygen, temperature and light regime. The Dehtář pond is used mainly for intense fish-pond management. Fishery Hluboká manages on this pond. Stock of the pond is polyculture. Dominant fish is common carp, next for example grass carp, pike, pikeperch and catfish. The pond is regular fed, limed and fertilized. From those data, it has produced the spatial and temporal visualisation of basic physiochemical parameters in the pond. From the spatial visualisation follows that the quality of inflow water, depth of water, meteorological situation and position of feeding area had a significant influence on physiochemical parameters. From the temporal visualisation follows that the highest differences in our data were during temperature stratification on 29th June 2016. This day range of the pH was from 7.1 to 9.1. During the other days pH was just about 8. On 29th of June 2016 the range of the temperature was quite high. The temperature was from 19.8 °C to 24.8 °C. Oxygen deficits were very often on this pond. Oxygen deficits had big influence on the death of fishes. The concentration of oxygen went down under the limit values (0.5 mg-l-1) for 2 times during the Vltava River Authority measuring. The local places of low concentration of oxygen had located on the depth of 1.5 m for 25 times during the Vltava River Authority measuring. The Vltava River Authority regularly takes measurements on the Dehtář pond. It should be used for better management and for preventing the critical situation, particularly the drop of oxygen, which could harm the fish. It should be limited feeding, because of the often oxygen deficits.
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The influence of the surrounding landscape , fishery management , external and internal factors on water quality in ponds
Janáček, Štěpán ; Vach, Marek (advisor)
The thesis deals with the influences that affect water quality in the ponds . It focuses on selected factors which define water quality . These include e.g. the amount of dissolved oxygen in the water , ammonia, etc. To determine the change in water quality in a fish breeding tank, measured quality of water at the inlet of the tank and at its drain. I enter into the analysis and facts about the amount of fish stocking in ponds , basin shape , location of the pond in the countryside , farming in the watershed .
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