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Hazard evaluation from GLOFs in the Cordillera Huayhuash
Baťka, Jan ; Vilímek, Vít (advisor) ; Šobr, Miroslav (referee)
Hazard evaluation from GLOFs in the Cordillera Huayhuash Abstract: Proglacial lakes in high-mountain regions recently experienced dynamic development related to the ongoing climatic changes. Most of the mountain ranges were widely studied with respect to hazards posed by proglacial lakes. However, the Peruvian Cordillera Huayhuash was omitted by any research of this type so far. In this thesis first, the author develops and assesses the inventory of glacial lakes in the Cordillera Huayhuash, and second, evaluates the hazard from GLOFs. After a thorough discussion and comparison to other world's major mountain ranges, significant conclusions are made. Most of the characteristics of the lakes in the Cordillera Huayhuash are influenced by a local factor - fluvial erosion that has occurred since the last glacial maximum. Nevertheless, general principles such as the statistical distribution of lakes according to their elevation that are valid to other compared regions may still be identified based on the data. Lakes of the Cordillera Huayhuash generally pose minor or even no GLOF hazard, the few exceptions were further analyzed in detail. Key words: geomorphology, GLOF, lake inventory, natural hazards, Peru
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Changes in extremity and seasonality of floods in the Zdobnice River basin
Čermák, Daniel ; Langhammer, Jakub (advisor) ; Šobr, Miroslav (referee)
The object of the bachelor thesis is to analyze the change of extremity and seasonality of floods in the Zdobnice basin. The literary research comprehensively presents floods with description of the biggest historical floods in the Czechia and in the Zdobnice basin. The literary research also includes the physical-geographical characteristic of the studied area. The practical part is based on the daily flow data analysis, obtained from CHMI (Czech Hydrometeorological Institute). Runoff analysis is performed on the base of these data, with focus on extreme flows. To compare the seasonality change, data series is divided into two periods (1945-1969 and 1970-2014), which point of change was determined by Pettit's and Buishand's homogeneity test. Seasonality change is compared by directional statistics, polar graphs, curves of cumulative frequency and flood index. As a result of these methods, it is found that in the second period, the flood risk is greater in earlier parts of the year. It has been also found, that there are more flood events in July. Key words: Floods, discharge, hydrological extremes, historical floods, seasonality, Zdobnice
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The natural environment of the planet Venus
Dergunova, Alexandra ; Kalvoda, Jan (advisor) ; Šobr, Miroslav (referee)
In the paper the current state of knowledge about the natural environment of planet Venus is described. The present state of affairs was determined by studies and evaluation of available data in specialized publications. The aims of presented bachelor thesis are in description of the planet as a whole, its atmosphere, landforms and internal structure. Special attention is attended to morphography of the Venus surface with an intention to characterize the main morphostructural landforms and related types of relief- forming processes. The physical and chemical processes operated in partial spheres of the planet substantially determinate the evolution of its landforms. Morphographical arrangement of landforms on the Venus is documented by a global topographic map and by groups of selected remote sensing images of the planetary surface. The current state of knowledge of the Venus topography can already be used to systematical investigation of the origin and intensity of landform changes, namely during the long-term development of its lithospherical crust by endogenous processes. Documentation of these morphogenetic processes and phenomena in up to the present published results of space missions was a stimulus for the proposal of morphostructural interpretation of main types of the Venus landforms....
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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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Origin and evolution of proglacial lakes in the Patagonian Andes
Danišová, Dominika ; Vilímek, Vít (advisor) ; Šobr, Miroslav (referee)
Origin and evolution of proglacial lakes in the Patagonian Andes ABSTRACT: Proglacial lakes are dynamic water bodies affected by the evolution of glacier ice masses, morphology and climatic factors. Mountain glaciers are very sensitive to climate change, which has caused their continuous recession recent decades. Glacier retreat is closely linked to an increase in the volume of proglacial lakes, especially in high mountain areas. The growth of proglacial lakes can also lead to increased probability of overtopping or dam rupture, also known as GLOF. The first aims of the presented thesis are to describe how proglacial lakes are formed, what factors can influence their continuous evolution and, lastly, how the lakes can affect their surroundings. In order to perform the spatial and temporary analysis, an inventory of the proglacial lakes in the North Patagonian Icefield was made, as this area has not yet been properly studied. In the time scale from 1984 till now, 640 lakes were characterised. The results show that along with glacier retreat, proglacial lakes are increasing in both size and number. However, the correlation with the climatic data is limited because of its poor quality and inadequate distribution in this area. Keywords: glacial lakes, glaciers, lake-dams, North Patagonian Icefield, GLOF
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Analysis of flood on Sázava River in February 1909
Jelínková, Karolína ; Šobr, Miroslav (advisor) ; Kašpárek, Ladislav (referee)
This Diploma Thesis deal with complex assessment of spring flood in 1909. In the theoretical part there are described types of floods. It focuses on rain-on-snow events together with melting of the snow and ice phenomena on streams. It also describe hydraulic models and especially in detail AquaLog model and its individual parts. The flood in 2006 which is compared to the event in 1909 is also described in more detail. In the historical archive there were found informations about flood in 1909 and because of them we know its area range. Next the flooding waves in Czech Republic were analized. The AquaLog model was used for basin of the river Sazava. Flooding waves were simulated for 9 stations in the whole basin using this model.
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Runoff development in selected catchments in the Kyrgyz Range, Tian-Shan
Jedličková, Šárka ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
The main objective of this paper was to investigate runoff changes in the catchment Ala-Arca, Alamaedin and Kara-Balta in Kyrgyzstan, as well as change in climate conditions from available stations in the area. The runoff, precipitation, and temperature series were subjected to monthly, seasonal and annual analyses based on available data. Both absolute and relative data homogeneity were verified using statistical tests such as the Mann-Whitney-Pettit test, the SNHT test, and the WiIlcoxon's two- sample test for absolute homogeneity, and the Alexandersson's test for relative homogeneity. The Mann-Kendall test was used to determine the trend in each serie. There were inhomogeneities found in a number of runoff data. In most cases, the changes of rivers Ala-Arca and Kara-Balta were recorded in 1987. Compare to Ala-Arca and Kara-Balta, the changes of river Alamedin were recorded 3 years later, in 1990. There was a positive trend development by the rivers with the glacial-snow regime. However, there was no statistically significant trend for the entire time series. Key words: runoff change, precipitation, temperature, glacial-snow regime, snow-glacial regime, homogenization, Mann-Whitney-Pettit test, trend, Mann-Kendall test, glaciation, Kyrgyzstan, Tien- Shan
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Interaction of groundwater and surface water under period of hydrological drought in the floodplain of the upper Lužnice River
Korejs, Tomáš ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
The object of this thesis si to evaluate the interaction of groundwater and surface water under the period of hydrological drought in the floodplain of the upper Lužnice river. The thesis tries to show the influence of the groudwater in the river floodplain during the period of hydrological drought and its correlation with the surface water state. The area of interst of the upper Lužnice is characterized by a unique ecosystem of unique natural value. It is a preserved river floodplain, which plays an irreplaceable role in fluvial processes, especially in water retention. The objectives were solved based on the monitoring of groudwater and surface water states from data obtained from the PřF UK profiles, which are represented by boreholes aross the floodplain and level meters in the watercourse. From the data obtained, it was possible to create a final analysis and to determine the behaviour and the mutual interaction between the surface water and groundwater in this natural floodplain. A detailed analysis has confirmed, that the interaction between watercourse and the floodplain and its retention potential. It can be said that during the hydrological drought, the water state or discharge in the watercourse is improved by water from the floodplain. The subsidy is only evident in certain stretches of...
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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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Identification and characterisation of abolished water reservoirs areas using GIS
Wolfová, Helena ; Matoušková, Milada (advisor) ; Šobr, Miroslav (referee)
This bachelor thesis aims to identify areas of small abolished water reservoirs using old maps and digital terrain model of the 5th generation. The main methodologies include georeferencing of old maps, followed by creation of an utmost detailed digital terrain model and field reconnaissance on the selected sites of abolished small water reservoirs. Changes in the land cover of selected abolished reservoirs as well as the change of the total water area in the study area were analysed. The thesis uses data obtained from Povodí Ohře s.p., the 5th generation digital model of relief, the old maps of the II, and III. military survey and maps in the S-52 coordinate system. The basin of Skřiváň brook, belonging to the basin of Svatava river, was selected as the study area. It was discovered that more than a half of the reservoirs disappeared during the 20th century. The most significant decrease was noticed during the 19th century. Area of small water reservoirs decreased to 40.51% of the original area from the period of the II. military survey. Key words: old maps, abolished water reservoirs, digital terrain model of the Czech Republic of the 5th generation, Svatava basin
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