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Development of fluvial lakes in the Lužnice River floodplain
Hastíková, Petra ; Šobr, Miroslav (advisor) ; Havlíková, Petra (referee)
The object of the thesis is to evaluate the development of several chosen fluvial lakes in the basin of the river Lužnice, mainly in the section between the border with Austria and Suchdol nad Lužnicí. The river Lužnice in this particular section represents low intensity of modification. Many fluvial lakes are situated there and the river is meandering remarkably in the area. The first part of the thesis deals with the characteristics of the natural conditions in the basin of Lužnice and the defined floodplain and the problematics of lakes and their determination. The main part of the thesis focuses on the evaluation of the flow development and fluvial lakes of the Lužnice floodplain based on the data of a aerosnapshoting. Because of the gradual decease of the meanders and straightening of the flows, it is possible to claim that the river has been considerably shortened with the passing time. In the thesis, 34 chosen fluvial lakes, that were measured morphometrically and batymetrically, were studied in detail.
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Hydrological drought on the Lužnice River in 2018
Junková, Anna ; Šobr, Miroslav (advisor) ; Matoušková, Milada (referee)
This bachelor's thesis elaborates on hydrological draught on Lužnice river at 2018. First part is focused on literary research on draught types, causes and impacts. Following chapter evaluates hydrological draught in Czechia between 2014 and 2018. This research serves as a resource for the main part of the thesis, which deals with hydrological draught on Lužnice river at 2018. Computations are based on threshold level concept and deficit volumes methods. Analysis is performed on the basis of data series from limnigraphic stations Pilař and Bechyně. These profiles are compared for the purpose of determining differences. The results of the work show that the hydrological year 2018 on Lužnice river was very important year in modern history in terms of drought. Key words: hydrological drought 2018, deficit volumes, threshold level, Lužnice river
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Causation of develpment change of selected fluvial lakes of Lužnice River in profile Základna
Jaček, Matouš ; Šobr, Miroslav (advisor) ; Havlíková, Petra (referee)
The aim of this thesis is to evaluate developement of selected lakes in area Základna in upper Lužnice basin. The area of interest is located in nature reservation Horní Lužnice, which extends from state border with Austria to Suchdol nad Lužnicí. This part of the river is very preserved almost without any anthropogenic influence. Eventhough it is the middle part of the river, it has developed floodplain with meandering belt, which is typical for lower parts of rivers. Because of its conditions, this area is very convenient for observing natural spills and studying fluvial lakes, which occure here in huge amount. First part of this work describes characteristic of the study area, fluvial lakes and natural spills and floods in the area. The main second part focuses on research of selected lakes and their developement. During several field researches the lakes were mapped and measured and soil samples were taken from the lake beds. Furthermore flow in floodplain during river spill was measured and data from automatic surface level sensors were evaluated, which show mutual connections of fluctuations of the lakes and the river. In conclusion the results of measurement were compared with previous theses regarding this area. Main results are that common spills cause clogging of lakes but intense floods...
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Influence of groundwater on hydrologic drought in the Lužnice River floodplain
Korejs, Tomáš ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
The object of this thesis is to evaluate influence of groundwater on the period of hydrological drought in the Lužnice river floodplain, focusing on interaction between surface water and groudwater. Floodplain of the Lužnice is unique fluvial ecosystem characterized it's diversity and natural value. Especially upper stream of Lužnice represents river floodplain river and creater good conditions for water retention. Main first part of this thesis is focused on work with literature about issue interaction between surface water and groundwater in the river floodplain with examples from Czech republic and the world, including the characteristics the groundwater Work with literature is also focused at characterizing the types of drought, it's cause and consequences. The second part evaluates the basic characteristics of runoff and hydrological drought on the Lužnice. This analysis is based on statistical evaluation of longtime data series from Pilař and Bechyně stations. Both profiles are compared to identify correlations.
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Interaction of groundwater and surface water under extreme hydrological conditions in the floodplain of the upper Lužnice river
Fialová, Petra ; Janský, Bohumír (advisor) ; Šobr, Miroslav (referee)
The object of this work is an analysis of the influence of extreme hydrological events (floods and droughts) in terms of interaction between groundwater and surface water in the river floodplain. The aim of this thesis is also the evaluation of the hydrological regime of the upper Lužnice basin and evidence of retention potential preserved natural floodplain. The selected objectives of the work were resolved on the basis of the values of groundwater levels and surface water in the area of interest. Based on data from underground wells and a digital terrain model, it was possible to create an image of the distribution of groundwater levels in river floodplains during selected hydrological situations. Data from surface flow was obtained from several habitats in the flow direction Lužnice. This has enabled graphically illustrate individual flood waves and characterize their size, speed and transformation after the passage of a preserved natural floodplain of Lužnice river. Carried out research has been confirmed retention capacity of the floodplain, which is most significant at flow rates slightly in excess of the flow capacity of the river bed. However, extreme floods or in periods with many culminations in a relatively short time leads to reduces water retention capability of the floodplain. In...
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Development of fluvial lakes in the Lužnice River floodplain
Hastíková, Petra ; Šobr, Miroslav (advisor) ; Havlíková, Petra (referee)
The object of the thesis is to evaluate the development of several chosen fluvial lakes in the basin of the river Lužnice, mainly in the section between the border with Austria and Suchdol nad Lužnicí. The river Lužnice in this particular section represents low intensity of modification. Many fluvial lakes are situated there and the river is meandering remarkably in the area. The first part of the thesis deals with the characteristics of the natural conditions in the basin of Lužnice and the defined floodplain and the problematics of lakes and their determination. The main part of the thesis focuses on the evaluation of the flow development and fluvial lakes of the Lužnice floodplain based on the data of a aerosnapshoting. Because of the gradual decease of the meanders and straightening of the flows, it is possible to claim that the river has been considerably shortened with the passing time. In the thesis, 34 chosen fluvial lakes, that were measured morphometrically and batymetrically, were studied in detail.
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Hydrological regime of the upper Lužnice river
Svoboda, Pavel ; Janský, Bohumír (advisor) ; Šobr, Miroslav (referee)
The aim of this paper is evaluation of hydrological regime of the upper part of Lužnice River basin. Upper stream of the Lužnice river represents low intensity of modification. Larger part of the river is a meandering stream with many ponds and pools in the floodplain where the safe retention of water during floods is possible. First part of this paper focus on detailed area hydrography description. The main part concentrates to hydrological regime. The methodology of this research is based on statistical evaluation of the longtime data series from the Pilař station. Flood events and dry periods are analyzed during the past 46 years. Detailed discharge measurements (realized in this area by Faculty of Science, Department of Physical Geography and Geoecology) are used for recent flood evaluations. Higher occurrence of floods and dry periods was identified in the past 10 years.
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Hunting behaviour of the wild population of river otter (Lutra lutra) in conditions of the shallow river.
POJEROVÁ, Lucie
Eurasian otter belongs to the group of endangered species. Its decrease was caused by the decline of suitable biotopes and the pollution of waste water. The human activity is considered to be another important reason for its decrease. Eurasian otters were hunted for their fur and for the losses on fish population. Although the number of Eurasian otter has been increasing lately, it is still important to protect these carnivorous animals. This bachelor thesis deals with the issue of foraging behaviour of the wild population of Eurasian otter. The aim of the thesis is to demonstrate the problems of otter?s foraging behaviour in shallow river; mainly the technique of this type of hunting. It was found that in the shallow river of the Lužnice River, the otters prefer rather the hunt-type of ?patch fishing?, which is usual while hunting in deep water. This kind of hunt has different characteristic since the preys are fish which are active during the daytime, contrary to inactive preys known from deep water of lakes and sea coasts. In the Lužnice River there were observed male and female otters and juvenile individuals. There was also observed the number of diving sessions during hunting session, the number of dives and hunting success set by the number of successful diving sessions.
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