National Repository of Grey Literature 86 records found  beginprevious66 - 75nextend  jump to record: Search took 0.00 seconds. 
Comparative analysis of runoff in experimental basins of upper Otava River
Fialová, Petra ; Janský, Bohumír (advisor) ; Jelínek, Jan (referee)
This bachelor thesis summarizes knowledge and provides new analyses about the runoff regime of three experimental streams in headstream area Otava River. The main focus is concentrated on comparison between the experimental basins in physical-geographic conditions, climate environment and peak flow. This thesis is based on data acquired during more than four years field survey which was realized in this area by the Faculty of Science, Department of Physical Geography and Geoecology.
Streamflow generation process and its dynamics in the Otava river headwaters
Kocum, Jan ; Janský, Bohumír (advisor) ; Hladný, Josef (referee) ; Kříž, Vladislav (referee)
In context of catastrophic floods and extreme droughts in recent years there is an urgent need of solving of issues dealing with protection against hydrological extremes, not using just classical engineering methods but also untraditional practices. There is a new protection strategy focusing on gradual increase of river catchment retention capacity including its headwater regions. All of the issues related to various possibilities and measures leading to river headstream areas retention capacity increase should be discussed by experts in various fields taking into account objectives and priorities of a supra-regional, regional and local significance. Natural runoff process is affected by man already by its birth, thus in headwaters where numerous procedures related to runoff retardation and water retention increase in headstream areas could be realized. Suitable conditions for the research realization at present is related to the Otava River headwaters (sw. Czechia) representing the core zone of a number of extreme runoff events and with high heterogeneity in the terms of physical-geographic and socio-economic aspects. To understand and clarify the runoff generation process and the effect of various physical-geographic factors on its dynamics, the detailed analyses of runoff regime in chosen...
Specific water properties of pit lakes in the Czech Republic
Hrdinka, Tomáš ; Janský, Bohumír (advisor) ; Benešová, Libuše (referee) ; Herber, Vladimír (referee)
Anthropogenic lakes constitute a significant part of the Czech countryside water component which has not been given sufficient attention so far. The presented thesis deals with the assessment of variability of physico-chemical properties of water in 30 selected pit lakes in order to identify specific features associated with quarrying of different mineral raw materials, basin morphometry and trophic level of the lakes affecting the quality of accumulated water. In the second part of the thesis the author deals with the comprehensive limnological study of the Hromnické Lake with extreme water chemism resulting from excavation of pyritic shales and focuses on the phenomenon of meromixis especially. The results are based on the evaluation of physical properties of water in the lake vertical profile (temperature, conductivity, dissolved oxygen, pH, transparency and colour) and chemical analyzes of water samples collected from the surface and bottom of the lakes during the four seasons in 2003-07 (determination of Ca, Mg, Na, K, Nammon., NO3 - , SO4 2- , Cl- and alkalinity), including determination of chlorophyll-a. In the case study of the Hromnické Lake conducted in 2010-11, the analysis of hydrological regime of the lake, determination of PO4 3- , TOC, selected metals (Fe, Mn, Al, Zn, Ni, Cu, Co,...
Hydrography and runoff regime of the Úpa River
Vlčková, Petra ; Janský, Bohumír (advisor) ; Kocum, Jan (referee)
This bachelor thesis presents, in the first part, physical-geographical characteristics of the Úpa River basin. It is described in terms of geology, geomorphology and soil characteristics, biogeography, land cover and climate. The individual characteristics are based on the research from scientific literature. The next part details the hydrography with absolute and descriptive characteristics of the basin and river network. The third part focuses on the evaluation of the runoff regime of the river Úpa, which is based primarily on processing and evaluation of data series from 1988 to 2011 from the Česká Skalice and Zlíč stations. Analysis of the runoff is carried out through daily, monthly, and annual flow regimes. Key words: Upa river basin, hydrography, runoff regime, flow rate
Hydrological drought in the context of climatic change in the world and in the Czech part of Elbe River basin
Šachová, Barbora ; Kocum, Jan (advisor) ; Janský, Bohumír (referee)
Hydrological drought in the context of climatic changes in the world and in the Czech part of Elbe River basin Abstract The submitted thesis deals with the hydrological drought as one of extreme runoff situations in relation to climate change. Part of this work is a comprehensive research sources to Czech and foreign literature defining the concepts and the development of hydrological drought due to the physical- geographic and anthropogenic factors. Low flow characteristics and methods for defining the drought events are described. Attention is paid to the possibilities of prevention and compensation of negative impacts of drought. Within the second part the presence of low flow in Elbe River subbasins, Blšanka River, Rakovnický Brook and Vydra River, is analyzed. Water deficit is evaluated with regard to the physical-geographic characteristics and the specifics of water resources use. Outline of possibilities to increase the retention capacity of study catchments is given. Key words: hydrological drought, low flow, runoff regime, retention potential, Blšanka River, Rakovnický Brook, Vydra River
Geographical division of the World Ocean
Kohoutková, Lucie ; Janský, Bohumír (advisor) ; Šobr, Miroslav (referee)
Geographical Division of the World Ocean Abstract Delimitation of ocean boundaries has a big importance for coastal as well as continental countries due to economical, political and other concerns. Division of the World Ocean varied a lot in the past and significant regional differences of its concept were formed. Not only the location of boundaries but even the number of identified subdivisions of the ocean varied. Some oceanographic schools which don't recpect international agreements and delimitate their own ocean boundaries still exist. Thanks to that there are still many problematic areas where neighbouring countries arque about a part of the ocean. The prefence for boundaries delimitation is very important and often also controversial. Tree main oceans - Pacific, Atlantic and Indian Ocean - are traditionally delimitate separetly for what many reasons exist. Many authorities still doubt about the independence of the Southern Ocean. The publication of 4th edition Limits of Oceans and Seas where the Southern Ocean should be officially accepted will be very significant. Keywords: Division of the World Ocean, ocean boundaries delimitation, the Southern Ocean
Risk analysis methods of natural catastrophic processes in high mountain areas
Falátková, Kristýna ; Janský, Bohumír (advisor) ; Engel, Zbyněk (referee)
Glacial hazards such as ice or rock avalanches, debris flows, jökulhlaups or glacial lake outburst floods threaten lives and livelihoods of people. They may grow to unexpected magnitude, travel very long distances and afflict vast areas. To prevent loss of life and human installation damage, risk analyses need to be assessed for hazardous regions. There are various methods to gain information on slope stability, geology of moraine dam or loose debris availability. They can be divided into those used during terrain on-site research and methods of remote sensing. Based on processed data a risk analysis is created and mitigation measures are carried out if necessary.
Water and sediment chemistry of fluvial lakes of the Elbe River
Chalupová, Dagmar ; Janský, Bohumír (advisor) ; Jelínek, Emil (referee) ; Benešová, Libuše (referee)
The presented paper aims at the problems of fluvial lakes in middle course of the Elbe River which has been influenced by the human activity since the Middle Ages. The oxbow lakes which are extremely precious ecosystems contributing to the stability of the river ecosystem show not only the changes of the course of the Elbe River. With regard to sedimenting a great amount of pollutants, these lakes also tell about the industrial pollution to which the river was exposed mainly in the second half of the 20th century due to insufficient precautions on industrial sources causing contamination. 5 cut lakes between Hradec Králové and Mělník have been studied within this research. These lakes differ in the intensity of communication with the river, in the distance from significant sources of industrial pollution and in the use of nearby land. The research included morphometric and bathymetric measures, observation of hydrological regime, seasonal measures in the water column and regular analysis of surface water samples. Profiles of sediments in the length that the used technology allowed were sampled, so that older anthropogenic load could be found out. The amount of organic carbon and concentration of selected metal and arsenic (Ag, Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) were stated apart from grain size...
Comparing Study of Fluvial Lakes in Middle Part of Elbe River and Upper Parts of Lužnice and Svratka River
Havlíková, Petra ; Janský, Bohumír (advisor) ; Pithart, David (referee) ; Pokorný, Jan (referee)
COMPARATIVE STUDY OF FLUVIAL LAKES IN FLOODPLAINS OF THE ELBE, LUŽNICE AND SVRATKA RIVERS Petra Havlíková ABSTRACT The aim of the thesis was to specify key differences in chemistry and biota (zooplankton communities) among fluvial lakes in three regions of Czech Republic: "střední Polabí" (central part of the Elbe River on the territory of Bohemia), "Horní Lužnice" (the upper part of the Lužnice River on the territory of Bohemia), and the Svratka River near Milovy (upper part of the Svratka River). The 10 studied lakes of the three regions differ in size, geology, shading, the influence of the river, and the level of anthropogenic impact. The following hypotheses were tested: 1) The chemical composition of the water in fluvial lakes is significantly different in different areas (floodplains). In the central Elbe River floodplain, there are the highest values of conductivity and concentrations of organic matter and nutrients. Fluvial lakes of the Svratka River floodplain near Milovy show the lowest level of these parameters, and fluvial lakes of the upper Lužnice River occur between the two previous regions. 2) The chemistry of fluvial lakes that have contact with the river through surface connection is significantly influenced by the river, and differs from the chemistry in fluvial lakes without any direct...
Specifics of the use of Latin American flora in terms of time and space
Svobodová, Eva ; Opatrný, Josef (advisor) ; Janský, Bohumír (referee)
In my studies "Specific Patterns of Latin American Vegetation From Perspective Of Time and Area" I introduced basic terminology and statements from climatology and bio-geography focused on Latin America's continent conditions. I also included in my studies history of agriculture, specific aboriginal growth and in a separate chapter i mention Czech explorers, who helped to uncover and recognise flora of Latin America.

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