National Repository of Grey Literature 181 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Measurement of Stream Flow Rate Using Salt Dilution Method
Burdych, Marek ; Ondovčin, Tomáš (advisor) ; Slavík, Martin (referee)
Tracer dilution method for measuring flow rate in surface streams is the main topic of the bachelor's thesis. The first part contains a summary of the most important flow measuring techniques for surface streams, including current meter, float method, FlowTracker, ADCP, volumetric method, and computing techniques based on channel cross-section data. Large part is dedicated to tracer dilution method. The findings of field measurements of flow made on the Lo- děnice River using the salt dilution approach are detailed in the second section. Five conductometers were used to measure the water conductivity at three di- fferent sites. Conductometry was performed simultaneously in two different distances from injection site. Throughout the experiment, a sixth conductome- ter recorded the background conductivity value as a standard. The predicted flow values are compared to those acquired from nearby hyd- rometric station of the Czech Hydrometeorological Institute (CHMI) and from observations made using Flowtracker. Diferences in measured flow rate were interpreted as tracer losses. These losses were estimated. Keywords: hydrology, surface water, water stream, tracer dilution, conducti- vity, tracer
Reaction of surface water and groundwater to the hydrological drought in 2015-2018 in the Upper Lužnice river
Husarik, Pavel ; Burian, Alois (advisor) ; Šobr, Miroslav (referee)
The Bachelor's thesis focuses on the examination of drought as an extreme and complex phenomenon. It provides a clear overview of its types, causes, and impacts on the landscape and society. Furthermore, it discusses the response of surface and groundwater to dry periods. The theoretical conclusion specifically analyzes the period of hydrological drought in the Czech Republic between 2015 and 2018. In the practical part, the characteristics of monthly and annual discharges are evaluated, and the response of surface and groundwater is assessed using data. Data from both surface and groundwater, as well as precipitation totals from the ČHMÚ (Czech Hydrometeorological Institute) observation network, were utilized. Average precipitation totals were also taken into account. The evaluation of time series was performed in terms of precipitation-runoff regime, including exceedance lines and monthly flow distributions. The results indicated that the lowest average flows were recorded in 2018, which also saw the lowest average groundwater level. Conversely, the highest number of dry days occurred in the studied period in 2015. Keywords: surface water, groundwater, hydrological drought, the upper Lužnice river
Changes of physical-chemical parameters of surface water in context with hydrological extremes. Application in the Rolava River catchment.
Šajnarová, Lucie ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
6 Abstract The diploma thesis deals with changes in the physico-chemical parameters of surface flows in response to extremes, especially increased flows due to higher precipitation totals or melting snow. The basin of the upper Rolava with peat bogs in the basin and minimal anthropogenic influence was used. The main goal of the work was the analysis of the behavior of electrical conductivity during events when there was an increase in flow rates and the categorization of individual events according to this behavior. Furthermore, the influence of the pre-condition of the watershed on the events and the subsequent behavior of the electrical conductivity was also investigated. The 10-minute electrical conductivity and flow data from the automatic stations of the ecohydrology team of the Faculty of Science, UK, or ČHMÚ were used. Among the methods are data homogenization, construction of hysteresis loops, categorization of loops, calculation of indices for hysteresis loops and PCA analysis for the pre-condition of the watershed. In most cases, a reverse relationship of electrical conductivity behavior was observed during these events, the most common types of electrical conductivity behavior during flow increases include a slow decrease in conductivity with minimum values after the peak of flow (in light...
Use of surface water as a low-temperature source for heat pumps
Jordanov, Alexandr ; Špiláček, Michal (referee) ; Pospíšil, Jiří (advisor)
First part of my diploma thesis contains research of ground water, refrigerants and heat pump including its inner components. Second part contains calculation of heat exchanger water – antifreeze, which use heat from a river and it will be used for input to heat pump water – water.
Use of photoautotrophic microorganisms in bioremediation of surface waters
Mušálková, Petra
Extensive experimental work has been executed to examine suitability of the proposed approach. Throughout the experiments, phosphorus concentration in the media was measured spectrophotometrically, to confirm the amount of phosphorus uptake,\nthe intracellular phosphorus concentration was analyzed by ICP-OES spectrophotometry.\n
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Monitoring jakosti vody vybraného toku
Zálešák, Petr
The bachelor thesis focuses on the evaluation of water quality in the Velička River. The Velička is located in the Hodonín district in southern Moravia. Its total length is 40.2 km. Its source is on the western slope of Velká Javořina and flows into the Morava River near Strážnice. The water flow was monitored in eight profiles at two-month intervals for one year. The monitoring had two phases. The first phase consisted of taking a water sample and measuring some of the water quality parameters in the field using an instrument kit from Hach Company. These were indicators of pH, conductivity, oxygen content, and water temperature. The second phase was carried out in a laboratory by measuring the quality parameters from the water samples using a spectrophotometer. The concentrations of total phosphorus, sulphates, nitrate nitrogen, and chlorides were monitored. The quality of the water in the river was evaluated according to the ČSN 75 7221 standard and government regulation No. 401/2015 Coll. Total phosphorus was evaluated as the most unfavorable qualitative parameter.
Vliv pastevních pozemků na parametry vody v malém vodním toku
KUBELOVÁ, Barbora
The diploma thesis deals with the comparison of selected surface water properties in a small watercourse in the "Pasecký potok" and "Váčkový potok" river basins in 2018 and 2019. The evaluation was performed in three currency profiles- the upper specific profile of "Váčkový potok", the lower specific profile of "Váčkový potok" and "Pasecký potok". The differences between these streams are in the management of the landscape and in the use of the landscape by man, which means a significant effect on the chemistry of water in surface water. The monitored hydrochemical indi-cators in the profiles were electrolytic conductivity, pH, insolubles, nitrates, phosphates, total organic carbon, inorganic carbon, total carbon and total nitrogen. Limit values of Government Regulation No. 401/2015 Sb. were not exceeded in the upper profile of "Váčkový potok" and in the profile of "Pasecký potok". The values of total nitrogen was exceeded in the lower specific profile of "Váčkový potok".The basin of the lower profile of "Váčkový potok" is located near arable land and in this profile other values were higher- electrolytic conductivity, pH, nitrates, total organic carbon, inorganic carbon and total carbon were proved. Human intervention in the upper profile of "Váčkový potok" and in "Pasecký potok" is small. We can consider the state of ecosystems here to be the most similar to a natural landscape.
Vlastnosti povrchových vod v závislosti na charakteru krajinného pokryvu v malém povodí
VONDRÁŠEK, Vít
The present thesis covered statistical evaluation of the effect of the management method and the landscape cover on selected hydrochemical parameters of surface water. To obtain and evaluate the necessary data, a model zone was selected, located in the mountains of Novohradské hory. It consists of the upper and lower sub-basins of the stream of Bedřichovský potok, which is the left-hand tributary of the River Stropnice. The sub-basins differ in how management methods are practised locally. While the upper sub-basin generally consists of forests and permanent grasslands, the lower sub-basin has primarily arable land and, in some part, built-up areas. For this reason, it is possible to compare the two sub-basins and evaluate their effect on the selected parameters of surface water; these involved conductivity, concentration of unsuspended solids, total organic carbon concentration, total nitrogen, nitrate nitrogen and phosphate phosphorus. The results show and support a conclusion that surface waters in the lower sub basin, one that is utilised for agriculture, exhibit higher values of the parameters monitored than surface waters present in the upper sub-basin, one that features forest/grassland vegetation cover. It can be noted that arable land has a reduced retention capacity and is more prone to erosion due to its vegetation cover of lesser size; this is also the reason why it is not able to completely retain the desired substances on the agriculturally managed land. This results in deterioration of individual hydrochemical parameters in surface water, such as conductivity or nitrate nitrogen. The thesis is generally indicative of the importance of vegetation cover for the management of water in the landscape.
Mapování výskytu (anti-)progestagenních aktivit v povrchových vodách České republiky
KRULOVÁ, Jana
The aim of the bachelor thesis was to map the occurrence of substances with (anti-)progestagenic activity in surface waters of the Czech Republic. Samples were taken at 21 localities using POCIS samplers. Localities included the so-called closure profiles (end of the river basin) and significant sampling points along the profile of the river Elbe. The samples were transported to the laboratory, where they were extracted. (Anti-)PR-CALUX in vitro bioassay was used to detect (anti-)progestagenic activity. First, the cells were plated on a microtiter plate and, after 24 hours of incubation, exposed to a calibration series of the reference substance ORG 2058 for progestagenic activity or the reference substance mifepristone for anti-progestagenic activity and a series of diluted surface water extracts. After 24 hours of exposure, cell luminescence was measured in relative light units. The resulting hormonal activity was expressed in ng/l equivalents of the reference substance (ORG 2058 or mifepristone). Progestagenic activity was below the limit of quantification in the samples from all 21 sampling sites (<6-11 ng/l ORG 2058 equivalents) sampled in the year 2017. Anti-progestagenic activity was detected at 6 localities, ranging from 12 to 33 ng/l mifepristone equivalents. For comparison, 3 samples from the year 2016 were analysed. Anti-progestagenic activity was detected in the range from 14 to 48 ng/l mifepristone equivalents. Progestagenic activity was below the limit of quantification at all 3 localities. The occurrence of anti-progestagenic activity was detected mainly at localities where the chemical industry is in the vicinity. There are companies that can use certain substances with anti-progestagenic activity in the production of their products, such as polycyclic musk compounds, brominated flame retardants or bisphenols. The occurrence of anti-progestagenic activity in these localities could indicate the insufficient ability of industrial wastewater treatment plants to degrade substances exhibiting anti-progestagenic activity. The occurrence of anti-progestagenic activity in surface waters may have a negative impact on aquatic organisms, especially vertebrates. Exposure of these organisms to substances with anti-progestagenic activity could lead to reduced fertility and impaired gonad development.
Surface and ground water of the Libický floodplain forest
Bašta Spinali, Izabela ; Weiss, Tomáš (advisor) ; Slavík, Martin (referee)
In the Quaternary, the area of the Libický floodplain forest was shaped mostly by the action of the Elbe river. The river generated a structure of oxbow lakes, pools, wetlands, floodplain forests or wet grasslands. These are connected by shallow groundwater of the Quaternary aquifer. During the Upper Cretaceous period, the area of Libický forest was flooded by the sea, which resulted in the formation of the bedrock of Libický forest - now the Cenomanian aquifer of the Poděbrady mineral spring structure. This aquifer is part of the Bohemian Cretaceous Basin. This thesis provides an overview about the waters in the area of the Libický forest, especially about: the development of the structures of surface water during the last ~2k years, groundwater of the quaternary aquifer and mineral water of the Poděbrady mineral spring structure. Finally, this thesis contextualizes this knowledge into climatic, geological, pedologic and also to ecological conditions of the area of Libický luh which is an important ecosystem in terms of biodiversity in otherwise relatively densely populated agricultural landscape. Key words: Libický luh, surface water, hydrology, Elbe, groundwater, hydrogeology, Cenomanian aquifer, Bohemian Cretaceous Basin, Poděbrady mineral spring structure, floodplain forest

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