|
|
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...
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Implementation of a long distance hiking trail along the Luznice River
Jiroudková, Petra ; Jarolímková, Liběna (advisor) ; Havelka, Jan (referee)
The bachelor paper Implementation of a long distance hiking trail along the Luznice River is concerned with hiking. The main purpose of the work is to map and define a long distance trail along the Luznice River with the view of German quality trails. The trail is called "The trail along the Luznice River leads us together". As the Luznice River springs in Austria, this project will be a matter of international partnership between the Czech Republic and Austria. The aim is not only the creation of the trail, but also the cooperation and communication of two countries. The greater focus is on hiking, the Czech Tourist Club (as the Lead Partner) and the trail itself. The next part of the paper indicates the trails potential for certification. The paper provides target groups, partnership, objectives and contributions to tourism.
|
|
|
HYGIENIC QUALITY OF FISH FROM SIGNIFICANT FISHING WATERS BEROUNKA 1, LUŽNICE 6, OTAVA 4, OTAVA 7 (P)
BARTOŇ, Jiří
The main aim of this study was to evaluate hygienic quality of fish from significant fishing waters: Berounka 1, Lužnice 6, Otava 4, Otava 7 (P). Sampling was performed in 2010 by electrofishing and fishing rods. 173 individuals belonging to 13 different fish species were fished. The samples of fish muscle were analysed for the following substances: Hg, Pb, Cd, PCB, DDT and its metabolites (DDE and DDD), a-HCH, b-HCH, y-HCH, HCB. Samples of bream (Abramis brama) muscle were collected at all monitored sites (exception was Otava 7) and bream was used as reference species to compare the contamination among monitored rivers. The results were compared with valid hygienic limits. The values of contamination were in most cases very low and far below the limits. Only mercury was identified as a risk contaminant in all monitored rivers. Average concentrations of mercury in the muscle of bream were in the range of 0.261-0.284 mg/kg and were comparable in all rivers. The hygienic limit for mercury (0,5 mg/kg) was exceeded only in 4 cases - one individual sample of bream from Otava, two mixed samples of asp (Aspius aspius) from Berounka and Lužnice, one mixed sample of perch (Perca fluviatilis) drom Otava. The highest value of total mercury content (0.768 mg/kg) was found in asp from Lužnice 6. All concentrations of persistent organochlorinated pollutants in fish muscle were far below the valid hygienic limits. The only health risk was posed by increased content of mercury.
|
|
|
Ecosystem services of a floodplain
Pithart, David ; Křováková, Kateřina ; Dušek, Jiří ; Žaloudík, Jiří
Natural segments of river floodplains have preserved the ability to provide a scale of ecosystem services. The aim of this study is to evaluate in a monetary way the selected ecosystem services of a natural segment of river Lužnice floodplain, Czech republic, based on the analysis and quantification of ecosystem processes and structures. Evaluated services are flood protection, carbon sequestration, biodiversity refugium and production of hay, wood and fish.
|
|
|
Natural flooding in Lužnice floodplain - a holistics approach
Pithart, David ; Montagová, Martina ; Hartvich, P. ; Černý, R. ; Prach, K.
Natural flooding was analysed in the Lužnice River floodplain in a holistic approach. Benefits of natural floooding can be summarised as folows: 1.Water retention is increased due to the soil absorption, evaporation, evapotranspiration, filling of oxbows, pools and natural depressions and finally the space between the river terraces. Real flood event are analysed here in terms of water distribution among these processes. 2. Natural flooding reduces the loss of ionts from the watershed by slowing the river outflow and loss of carbon loss by slowing the decomposition processes. 3. Flooding creates and maintains floodplain geodiversity by re-forming of floodplain geomorphology and keps its biodiversity by inoculation of biota into the floodplain subsystems and differentation of its impact on these subsystems. For these reasons, maintaining and enhancing of natural flooding seems to be a prerequisite of sustainable management of riverine landscape.
|
guest ::
