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Tracer tests with fluorescent dyes with respect to those tracing experiments where arrival of dye to water supply systems is expected and Tracer test in Chýnov Karst
Koutník, Jakub ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The thesis is dedicated to fluorescein tracer tests, especially those where the tracer ends in drinking water. The review part of the thesis describes the usage and characteristics of sodium fluorescein (uranine) and other fluorescent tracers in tracing tests. Special attention is given to the toxicity of fluorescent tracers and to the legislation limiting their use in the Czechia and abroad. The practical part of the work is to perform a fluorescein tracer test from Chýnov Cave to the Rutice Spring on distance 1260 m away. The tracer test has confirmed that the Rutice Spring is the only karst spring where water flows from Chýnov Cave. The results differ from previous tracer tests made on the same flowpath in 1962, 1965 and 1966. While previous studies have concluded that the mean tracer transit time is in the order of tens to hundreds of hours, this tracer test has shown that the mean tracer transit time is in the order of hundreds of days. This work has thus provided completely new knowledge about water flow in the Chýnov karst.
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Character of groundwater flow in highly permeable sediments of Bohemian Cretaceous Basin
Kůrková, Iva ; Bruthans, Jiří (advisor) ; Datel, Josef (referee) ; Tesař, Miroslav (referee)
The study focuses on water flow in sandstones and sandy limestones of the so-called facies transition in the western part of the Bohemian Cretaceous Basin. The area between Turnov, Milovice, Úštěk and Doksy is a part of most important aquifer in the Czech Republic, in terms of water supply. However, there are considerable discrepancies in hydrogeological concepts regarding groundwater flow in this area. The prevailing opinion is that quartz sandstones form the main aquifer, although largest springs are partly located outside the area of their occurrence. The aim of the work is therefore to determine which rocks are the source of the large springs and where diffused seepage predominate. Furthermore, to characterize the possibility of rock karstification, to describe the character of the channels and the flow in them, and at the same time to compare it with the flow in the adjacent porous environment in selected areas. Thermometry (winter profiling of temperature and conductivity along watercourses) was carried out in order to distinguish areas with large springs, diffused seepage and stream segments without any drainage. The karst potential of rocks was determined using calcimetry and adopted leaching tests. To determine flow velocity in karst channels and to characterize the channels, a series of...
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Groundwaters in vicinity of subway line A
Drábková, Jana ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The main aim of bachelor's thesis was to process and assess data measured during groundwater monitoring in the surroundings of construction sites of the new subway line A (21/04/2010 - 31/08/2011). The data from 17 monitored objects (subhorizontal mine galeries, springs and hydrogeological wells), which, with few exceptions, drain mainly Cenomanian aquifer (1 object in Orovician shales a 2 objects in Quaternary aquifer). For outflows from galeries and springs, statistics of the following parameters was calculated: discharge, pH, electric conductivity and water temperature. Discharge of all studied objects shows very low time variation. pH is neutral waters and overall, pH values show very low variability. Mean conductivity of studied objects suggests lower to moderate mineralization of waters. Groundwater temperature does not respond significantly to temperature changes at the surface. Marked temporary declines in water table leveal were probably caused by tunnel construction in proximity of the wells. Chemical analyses of groundwater from all 17 objects demonstrated that groundwater in the studied area belongs to the Ca-HCO3 type. Waters from different objects differ in increased concentrations of chlorides, nitrates or sulphates. Water is undersaturated in gypsum. Water is undersaturated in...
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Repeated tracer tests under different hydraulic conditions
Paděra, Martin ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The thesis deals with tracer tests conducted repeatedly at several sites under different flow rates. Number of parameters vary depending on flow rates, such as mean residence time, tracer concentration and recovery, the character of breakthrough curve. I compared results from various sites, including the results of my own measurements to see if it is some general pattern. As it turned out, generalization is not possible. Mean residence time can decrease with increasing discharge in one system, while it increases in the other one. The same can be said about tracer recovery. Both parameters are controlled mainly by geometry of karst conduits, especialy by volume of phreatic and vadose spaces in individual levels above and below the lowest water table in the system Breakthrough curve plays essential role in the description of the karst system. It's character varies depending on the flow rate and allows to characterize the karst system. By it's interpretation, it is possible to detect or locate bifurcation and describe the water distribution into discrete conduits.
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Characterization of hard rock environment: archive borehole data and conceptual model
Vacková, Alena ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
This study is focused on characterization of the hardrock environment in surroundings of Sazava river. It is based on the archival data of groundwater table in boreholes, results of pumping tests from Geofond database and topographic data (DMR , watercourse, etc.). ArcMap 10.1 and Excel were used for data processing. The relations between the groundwater table depth, water table gradient, specific yield, transmissivity and variety of topographic parameters (distance from a watercourse, elevation, relative elevation above the nearest watercourse, the terrain gradient, etc.) were studied. Close linear relationship exists between the gradient of the terrain and groundwater table (rxy 0.96) in the study area. Groundwater table gradient is on average 88 % of terrain gradient. Mean groundwater table gradient is 10 % (6). The average transmissivity in the area is 1.27 x 10-4 m2 /s, specific yield is usually between 0.01 and 0.1 l/s m. This corresponds to the low and very low transmissivity class. Variability of transmisivity values is high. The difference between transmisivity in discharge and recharge zone, assumed by previous authors, was not confirmed in the study area. Specific base flow calculated from mean transmissivity, terrain/ water table gradient and river network density based on Krásný and...
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Karstification of carbonato-silicate rocks: review of literature and leaching experiments
Vojtíšek, Jan ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The process of karstification doesn't occur only in easily soluble rock, such as limestone and evaporites, but also occurs in other rocks such as quartzites or siliciclastic rocks with carbonate cement. The "ghost rock" karstification is, unlike the classical karstification, two- step process, where the soluble component are dissolved first and subsequently the insoluble components are eroded and flushed away. These processes also occur in the Czech Republic, for example in the Bohemian Cretaceous Basin (BCB). Practical part of this thesis consists of leaching experiments of samples from BCB. Leaching in hydrochloric acid is an accelerated simulation of natural processes of dissolution by acidic solutions. Leaching of the samples in acid led to the decrease of sample strength, sometimes to their desintegration. The samples are probabbly prone to the evolution of karst conduits. Leaching experiments showed that the carbonate content is an important but not the only driving factor in the karstification process.
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Hydrology and hydrogeology of Bubovice Stream
Herza, Tomáš ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The Bubovice stream is typical by sinking water in some segments. Especially in last years the loss of water is so high, that the stream riverbed is mostly completely dry except the topmost part of the stream. What determines the intense water losses in Bubovice stream is considered an important issue. The objective of this theses was to determine the causes of water losses and find out, if at least a minimum flow of Bubovice stream could be restored. The solution of the problem is very complex, because the Bubovice stream basin is located in a karst region of Bohemian Karst, which is typical by its complex water flow in heterogenous rock environment. Historical documents show that water losses occurred already 80 years ago, before recent climatic change. The water losses are at present time twice as high as were in 1990s in the upper part of catchment of Bubovice stream based on discharge measurements. The losses are caused mainly by infiltration of water to limestone. The contribution of evapotranspiration to water losses is marginal. It was found that 2 out of 5 parts of stream catchment show permanent water losses. Based on very different concentrations of sodium and chloride ions it is evident, that water that sinks in the upper part of Bubovice stream catchment flows away from the orographic...
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Methods to characterize the intensity of recharge via riverbed due to groundwater abstraction
Bašus, Jan ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
EN There is an intense exchange of water between the quaternary fluvial sediments and river. Although the precise amount of seepage flow is needed for various hydrogeological models and calculations, the systematic measurements of the seepage flux in our country are lacking. This Batchelor thesis describes 4 methods that can be used to measure the intensity of water exchange between quaternary sediments and river flows. These are manual and automatic seepage meters, which isolate a small part of the river bed and measure the amount of water that is lost or gained. These two approaches differ by frequency of measuremens. Secondly, there are methods that measure the temperature distribution in the river bed with heat-sensitive electric sensors (point measurements) and light distraction in an optic fiber. The measured temperatures are used to simulate the water and heat flow in the river bad. At each of these methods, I described the method principle, the equipment used for measurement, the measurement methodology as well as examples of where were these methods already used. Discussion in the final part of the thesis contains comparison of the practical use of the mentioned methods. Key words: Seepage, Seepage meter, riverbed infiltration, water flow in riverbed.
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Tracer tests in karst with focus on new development in this field
Mareš, Jakub ; Bruthans, Jiří (advisor) ; Kůrková, Iva (referee)
The karst aquifers are formed by highly permeable conduits that allow very fast and concentrated flow. They can transport contaminants and endanger drinking water sources. Due to the large abundance of karstified carbonate rocks, it is necessary to prevent possible contamination. Tracer tests are used to determine the catchment and hydrodynamic parameters. These are constantly evolving to better simulate the transport of both dissolved and particulate substances and to minimize the risk of contamination. At present, particulate and colloidal tracers, such as DNA, are being developed to better simulate the movement of pathogenic bacteria. This bachelor thesis deals with this development. In the practical part, a tracer tests were carried out in the Bohemian Cretaceous Basin in the karst of the Jizera Formation, which utilized the obtained knowledge. There was injected NaCl and LiCl into a sinkhole in the settlement Borek and then conductivity was monitored and samples were taken at several places in the Vazovec stream, the spring of Bezednice and the springs near river Jizera. The tracer tests refuted the initial assumption that the water from the sinkhole flows directly into the Vazovec stream under the sinkhole and show one of the few found polyfurcations in the Czech Republic. Furthermore, it is...
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