National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.00 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
The influence of evapotranspiration on the groundwater of floodplain forests: Libický luh
Vašková, Hana ; Weiss, Tomáš (advisor) ; Slavík, Martin (referee)
The recherche part of this bachelor thesis deals with evapotranspiration from floodplain forests and its influence on the depth of the groundwater level and mineralization of groundwater. As floodplain forests in the Czech Republic are represented only in smaller fragments, there is a mention of the effect of mineralization on plants. The thesis describes the principle and use of stable isotopes in hydrogeology and the comprehensive characteristics of the area of interest of the experimental part, the Libický luh National Nature Reserve. The experimental part includes the observation of the level, conductivity, temperature, pH, and determination of the isotopic composition of the underground and surface water in Libický luh, where high mineralization of the groundwater was previously detected. The thesis discusses the effect of evapotranspiration on the content of dissolved substances in the water in Libický luh as a possible cause of this phenomenon. It was found that as the temperature rises, the groundwater level drops, and that mineralization remains relatively constant throughout the year. The drop in the groundwater level is evidently caused by intensive evapotranspiration from the floodplain forest during the growing season. However, longer time series of conductivity or hydrochemical...
Selected issues in hydrology and hydrogeology of the Trebon Basin
Nymsa, Zdeněk ; Slavík, Martin (advisor) ; Nedvěd, Jakub (referee)
In the last few decades, the average temperatures in the Czech Republic have been increasing, which has led to increase in evapotranspiration. Previous studies have shown that increases in evapotranspiration during the summer months can lead to significant reductions in flows and even to drying up of small watercourses. Additionally, snow cover has also been on the decline in recent years, resulting in no flow enhancement in spring months and therefore lower soil moisture problems ensue. Due to the possible decrease in precipitation and/or increase in evapotranspiration, there is also the risk of less groundwater recharge in the future. The aim of my thesis is to verify the correlation between several selected parameters in the Trebon Basin, namely the relationship between evapotranspiration, precipitation and baseflow and groundwater levels in boreholes. A sub-objective is to verify the long- term evolution of these parameters in the Trebon Basin. Atmospheric precipitation and its variability during the year have not changed since the 1960s, while the magnitude of potential evapotranspiration has statistically significantly increased over this time and its variability during the year has decreased. The difference between atmospheric precipitation and potential evapotranspiration has been...
Hydrogeological character of selected hardrock environments and groundwater recharge in populated areas
Krupař, Josef ; Bruthans, Jiří (advisor) ; Slavík, Martin (referee)
The purpose of this thesis is to adress the hydrogeology of hard-rock environment and groundwater recharge in urban areas. The theoretical part describes hydrogeology character of granite and ophiolite rock environment with emphasis on features such as transmissivity, storativity and hydraulic conductivity that corresponds to the fissuring of the rock environment. It is clear that fault tectonics is the most important factor that influence the hydraulic conductivity. Storativity, on the other hand, is most affected by fissured systems. Ophiolites are a more significant water supply aquifer than granites in terms of storativity. This thesis also describes groundwater recharge in urban areas and not only from precipitation but also through surface water reservoirs, leaks from pipeline network and by import of water from surrounding watershed. Practical part compares values of precipitation from 2013 to 2022 from four ČHMU stations. It compares PET (Potential evapotranspiration), API (antecendant precipitation index) values and their difference. Subsequently, in the practical part, the normalized relative groundwater recharge from the measured values of the well level is compared with the flow rate at all monitored locations and it is evaluated whether the time course of the recharge according to the...
Bank infiltration in area of Jordán meander on Orlice river
Drmota, Adam ; Hrkal, Zbyněk (advisor) ; Slavík, Martin (referee)
This thesis deals with the study of the Jordán meander on the Orlice River, where the watercourse has undergone extensive revitalization in recent years, which after several decades returned the watercourse to its original riverbed. In connection with the revitalization of the watercourse, an increase in the level of groundwater in the surrounding quaternary aquifer was expected. In this case we can call it artificial bank infiltration. In order to confirm this assumption, hydrogeological boreholes HV1 to HV4 were placed at the site, and they were used for groundwater level monitoring since year 2018. The results of the monitoring document the positive impact of the revitalization on the level of groundwater in the surrounding river alluviums. Furthermore, it was found that boreholes on different banks of the Orlice River react to flow rates in the river and revitalization measures, quite differently. Differences can also be caused by orders of magnitude different hydraulic parameters on both banks, which have been verified using field pumping tests. Keywords: Bank infiltration, monitoring, pumping tests, revitalization
Soil evaporation and its controlling factors
Fröhlich, Lukáš ; Slavík, Martin (advisor) ; Mareš, Jakub (referee)
Evaporation is one of the basic members of water cycle, affecting a wide range of natural processes. The importance of the study of evaporation is even greater under conditions of climate change. This bachelor thesis focuses on soil evaporation and its controlling factors. The way in which water moves in porous media is described, and the terms evaporation, transpiration and evapotranspiration are defined. The division of the soil evaporation process into three phases is described and relative evaporation rates characteristic for the different phases are summarized. The relationship between evaporation and the spatial distribution of moisture inside soil is explained. The influence of internal and external factors on the evaporation rate is then described. It is assessed whether these factors contribute to higher or lower evaporation rates and under which conditions this occurs. It is evaluated whether the degree of influence of these factors is constant or whether it varies according to the circumstances and the evaporation phase in which the factors operate. Key words: evaporation, transpiration, evapotranspiration, evaporation phases, flow of underground water, external and internal factors of evaporation
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
Approaches to estimate wetland evapotranspiration and the evapotranspiration loss of groundwater from wetlands in the Liběchovka and Pšovka catchments
Pátek, Karel ; Bruthans, Jiří (advisor) ; Slavík, Martin (referee)
This work is dedicated to the study of evapotranspiration in wetlands. The theoretical part is an overview of methods that are used for estimation of evapotranspiration, especially in the wetland environment. The practical part is focused on measurement of evapotranspiration in the wetlands located in the upper part of the Pšovka and Liběchovka river watersheds. Periodical fluctuations of water table and water flow in the stream were observed there due to evapotranspiration. The role of evapotranspiration was dependent on the mean daily temperature and sunshine duration. For the warm sunny days the fluctuations indicated that in the studied wetland the maximal daily evapotranspiration can cause 32 % decrease of water flow in the stream. The evapotranspiration derived from stream flow oscilation reached 86 % of potential evapotranspiration based on Oudin method. Potential evapotranspiration in the Liběchovka wetlands in summer is capable to decrease the discharge of Liběchovka in similar way as groundwater abstraction.
Origin of karst conduits and caves in Jizera Formation in Turnov.
Slavík, Martin ; Bruthans, Jiří (advisor) ; Schweigstillová, Jana (referee)
Aim of this study is to characterize the processes responsible for evolution of open conduits and caves in Jizera Formation near Turnov, in particular to distinguish if the main factor acting in enlargements of conduits is dissolution and the conduit system can be called karst, or if the process is caused by erosion of weakly cemented sandstone without contribution of dissolution. An important part of the study is to introduce the concept of self-organization. Based on results from accelerated simulation of dissolution of twenty rock samples, SEM analysis and drilling resistance, I have proved that rocks in Jizera Formation near Turnov dissolve in an acidic environment and their strength characteristics does not enable direct erosion by flowing water. Samples from localities of "Bartošova pec", "Slepé údolí Podhorčí", "Rozsedlinové ponory pod Drábovnou", "Šetřilovsko", "U Kačeny" and "Semikraska" dissolve, but behavior of samples from "Sudoměř - rybník" and "Sudoměř - Skalský potok" is in an acidic environment very similar to samples from Teplice Formation "Skalní pískovcový výchoz u Podhorčí" and "Valdštejn".

National Repository of Grey Literature : 28 records found   1 - 10nextend  jump to record:
See also: similar author names
13 SLAVÍK, Martin
3 Slavík, Marek
2 Slavík, Matěj
8 Slavík, Michal
2 Slavík, Miroslav
1 Slávik, Mark
13 Slávik, Martin
2 Slávik, Matěj
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