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Water losses in the Loučenský brook and Bouřlivec basins and the possibilities of their reduction during the hydrological drought
Junková, Anna ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
This thesis deals with the problem of water losses in the Loučenský brook and Bouřlivec basins. It was written on the basis of a project for the state enterprise Povodí Ohře, which dealt with the management of these streams. Loučenský potok and Bouřlivec are the sources of water for the Všechlapy reservoir, which provides a number of functions in the reservoir surroundings. However, the Všechlapy reservoir has been threatened by hydrological drought in recent years. For this reason, it is necessary to determine the water losses in the basin and focus on possible methods to ensure that the reservoir has sufficient water levels to maintain all of its major functions. In the first part of the thesis, the theoretical background related to the issue is explained. In the practical part of the thesis, water losses in the basin are detected mainly on the basis of longitudinal profiling of flows and recorded water withdrawals. Flow measurements were carried out on a total of 43 profiles in five different hydrological conditions with a focus on the dry season. The results show that there is a need to look for reserves in two areas. Firstly, in the management of the ponds, where it appears that a significant amount of water is being lost throughout the basins, and secondly, in the small-scale users who draw...
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Analysis of hydrological drought and trends of rainfall-runoff data in the Bouřlivec and Loučenský stream basins
Vítková, Petra ; Šobr, Miroslav (advisor) ; Matoušková, Milada (referee)
The diploma thesis deals with the evaluation of hydrological drought in the Bouřlivec and Loučenský stream basins, located in the northwest of the Czech Republic in the Ore Mountains. Available hydrological and climatological data series from two limnographic and four climatological stations were used to characterize the hydrological drought. The intensity of the occurrence of hydrological drought in the stream basins of interest was assessed using the method of threshold values and the method of insufficient volumes. According to the results of the work, the hydrological year 2020 was marked as extremely low in water on both monitored profiles, which points to the accumulating causes of drought from previous years. In terms of hydrological drought, the year 2018 was also significant. The diploma thesis also aims to detect trends in data series of precipitation, air temperature and inflow into the Všechlapy reservoir using the Mann-Kendall test. The results of statistical testing of the trend point to an increasing trend of air temperature and a decreasing trend of the inflow into the Všechlapy reservoir. A significant trend in the precipitation data series was not confirmed. Trend testing was preceded by an assessment of the homogeneity of the available data sets. Last but not least, emphasis is...
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Arctic sea ice variations from the point of view of the global climate change
Škopan, Viktor ; Huth, Radan (advisor) ; Šobr, Miroslav (referee)
The Arctic is one of the regions of the Earth most vulnerable to climate change. Temperatures in the Arctic have risen by more than twice the global average over the past few decades and are roughly 4 řC above the temperature at the start of the Industrial Revolution, which occurred in the late 18th century. It is highly likely that anthropogenic activity is responsible for such a dramatic change. The Arctic sea ice responds to these changes by decreasing in area, thickness, age and other parameters. The most significant decline has been recorded in the summer months, when the area of the sea ice is shrinking at an average rate of 12.8 % per decade. There has also been a significant decline in the age of sea ice. Forty years ago, sea ice older than four years accounted for 30 % of the total area covered by sea ice, whereas today such old ice accounts for only 2 %. Positive climate feedbacks are contributing significantly to the rapid warming of the Arctic and increased sea ice melt. An example is the decreasing albedo (reflectivity) of the Arctic Ocean, which reflects much less solar radiation due to the shrinking sea ice, contributing to the faster warming of the region and higher sea ice melt. Models show that the warming of the Arctic will continue in the future, and temperatures in the Arctic...
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Integration of drainage measures in stream restoration projects. Application in the catchment area of the Klíšský Brook.
Vláčilová, Klára ; Matoušková, Milada (advisor) ; Šobr, Miroslav (referee)
This thesis deals with options of integration of drainage measures in stream restoration projects in rural landscape. The main aims are creation of research on the topic and creation of database of drainage systems in the area of interest, upper course of the Klíšský Brook. Partial aim is physical- geographical characreristics of the area of interest. The positive and negative effects of drainage are presented and discussed, and then adaptation measures to mitigate the harmful effects are described. The overview of drainage in the catchment is a synthesis of map data from the Register of Soil Blocks, data provided by the Ohře River Basin, drainage found in aerial photographs and field research. There are both main drainage facilities and drainage pipes in the area of interest. 10 surface canals and 7 drainages flow into the revitalized part of the Klíšský Brook. While the canals are still functional, the drainage is clogged with sediment, overgrown with vegetation and causes wetting. The results serve as a basis for the design of adaptation measures in the restoration of the Klíšský Brook. Key words: hydromelioration, drainage, rural landscape, adaptation measures, restoration, water retention
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Influence of rock glaciers on hydrological regime
Lencová, Kateřina ; Šobr, Miroslav (advisor) ; Falátková, Kristýna (referee)
Within this work, a literary research was performed on the topic of rock glaciers and their influence on river runoff. Rock glacier are features typical for high-mountain periglacial environment. Through the accumulation of part of the flowing glacial water, they significantly affect the timing and quantity of watershed discharge. In addition, stone glaciers preserve significant volumes of water in the form of buried ice, the gradual melting of which regulates river runoff, especially in the dry seasons. A physical- geographical characteristics of the Ala Archa river basin was performed and supplemented by a more detailed climatological characteristic of the study area based on the own processing of meteorological data from the Adygine meteorological station. The purpose of this work was to assess the impact of rock glaciers in the basin of eight selected rivers, which drain the Kyrgyz and Kungej Alatau, on their hydrological regime. It was found that the presence of rock glaciers in the monitored basins affects the runoff regime of these rivers, especially by reducing the differences between their June and July runoffs. Key words: rock glacier, hydrological regime, Tien Shan
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Classification of glacial lakes and methods of inventory
Pisarčíková, Alexandra ; Vilímek, Vít (advisor) ; Šobr, Miroslav (referee)
Classification of glacial lakes and methods of inventory Abstract: Classification of glacial lakes has its application all around the world. However, there is no unified system of typology that would make it possible to simplify and increase the effectivity of labour inventory. The thesis is dedicated to creation an overview of the definitions of glacial lake divided by euro-atlantic and asian literature and its resulting evaluation. The inventory of glacial lakes is closely connected to their classification. Therefore, the work subsequently presents individual methods that lead to the creation of a lake inventory. The basis of the creation of a design of the classification system is the research from already created glacial lakes classifications and analysis by which typology can be created. Overall, the classification of the lakes is divided into two main groups: by position to glacier or relief and according to the type of dam. Furthermore, 280 glacial lakes were analysed based on the inventory table in an interest area. On the basis of a created classification design, most of the lakes were classified under the inventory, thereby confirming its used application. Keywords: glacial lake, typology, classification, inventory, RS
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Hydromorphological survey as a basis for restoration measures of streams in urban areas
Jonáš, Miroslav ; Matoušková, Milada (advisor) ; Šobr, Miroslav (referee)
This thesis deals with hydromorphological survey using the HEM methodology (Langhammer, Hartvich 2014) and its application to the backbone streams of the Bouřlivec catchment. The aim is to determine the extent of anthropogenic modifications on these streams and their subsequent classification according to the corresponding classes of hydromorphological quality. In summary, 28,107 km of watercourses were mapped by field monitoring, which were divided into 101 morphologically unique sections. Each section was assigned a hydromorphological quality class according to the calculated hydromorphological status. In only 4,28 % of these sections, a state close to nature was stated. The remaining 95,72 % of sections show signs of anthropogenic modifications, which are evident especially in sections intersecting urban areas of towns and municipalities. The highest rate of anthropogenic modifications was identified in a total of 1,02 % of sections, which were assigned the worst class of hydromorphological quality. The sections that can be assessed as significantly modified make up to 18,24 % of the mapped area and the moderately modified sections cover 29,57 % of the area of interest. The final comparison of the two investigated streams clearly shows that the Loučenský brook significantly exceeds Bouřlivec,...
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Hydrological drought in the upper Mže catchment area
Lukášová, Karolína ; Janský, Bohumír (advisor) ; Šobr, Miroslav (referee)
Nowadays drought is a very actual topic. Hydrological drought is most often caused by a deficit of precipitation and it has been missing almost one year of rain in some areas in Czechia. This bachelor thesis focuses on the analysis of this type of drought in the upper Mže River basin, which is located in West Bohemia. In the basin there are these five gauging stations: VD Lučina and Stříbro on the Mže River, Planá on Hamerský brook, Třebel on Kosový brook and Stříbro on the Úhlavka River. The theoretical part defines the area of interest in terms of physiographic and runoff conditions. Furthermore, a research of the current knowledge about drought, its causes and impacts is performed. The practical part follows with the analysis, using data of the average daily discharges from gauging stations and two methods - threshold limit method and deficit volumes. Results are based on a mutual comparison of the stations and hydrological years. The biggest drought on the Mže River was registred in the period 1934-1935, since 1970s natural discharges were improved due to the built dam. The period 2018-2019 can be considered as driest years for the whole river basin. Key words: upper Mže River basin, hydrological drought, runoff, precipitation, physiographic conditions
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Hydrological and suspended load regime of the Odlezelské Lake
Hulec, Filip ; Šobr, Miroslav (advisor) ; Kliment, Zdeněk (referee)
The Odlezelské Lake is a natural, landslide-dammed lake in western Bohemia. Its lake basin is silting intensely and its volume decreases; it will be completely silted in the future. This work aims to evaluate the siltation of the lake primarily by evaluating the suspended load regime of its tributaries and comparison with data from bathymetric measurements. Within this work, data from the station network of the Department of Physical Geography of the Faculty of Science of the Charles University were used, which was statistically processed in order to describe the hydrological and suspended load regime. In addition, flow speeds in the inflow part of the lake were measured during two precipitation-runoff events using ADCP. The results show that most of the suspended load is transported during flood episodes, in contrast to the runoff, there is a significant interannual variability in the suspended load regime. Oppositely, the comparison of the suspended load regime and the bathymetric data proved as impossible due to a high sensitivity of the data.
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Siltation of the Újezd water reservoir
Kebertová, Daniela ; Šobr, Miroslav (advisor) ; Chalupová, Dagmar (referee)
This bachelor thesis focuses on the siltation of water bodies. In April 2020 the first accurate and detailed bathymetric survey of the Újezd water reservoir was conducted using an ADCP RiverSurveyor M9. The aim of the measurement was to determine volume of the reservoir after 39 years since its construction. The obtained data was processed in ArcMap 10.7.1 using the kriging method of interpolation. Based on it a new bathymetric map of current state of the reservoir was created. For the sake of understanding the causes of siltation, a complex physical-geographic characteristics of the upper stream basin of Bílina river, on which the Újezd water reservoir is situated, had been done. The river basin is fundamentally anthropogenically influenced by water supply system and mining activities. The volume of the reservoir at a water surface area of 117.20 ha was shown to be 4718364 m3 , 1.63% larger, compared to the values 4642640 m3 and 120.75 ha presented in the management manual for the waterwork. The volumes are comparable which indicates that there is no significant amount of siltation and the reservoir became a naturally functional and sustainable ecosystem.
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