|
|
Phytogeographical analysis of distribution of selected xero-thermophilous herbaceous taxa along the Sázava River valley in Central Bohemia
Vlasák, Tomáš ; Černý, Tomáš (advisor) ; Boublík, Karel (referee)
This study is focused on a phytogeographic analysis of the distribution of selected xero thermophilous herb taxa along the Sázava Canyon in Central Bohemia. The research was done in 62 localities scattered along the major river stretch from Ledeč nad Sázavou to the confluence of Sázava with the Vltava Riever. The Sázava River was divided according to the river mileage into 8 even sections where there were 6 or 7 larger representative localities further selected. In each locality there was obtained the semi quantitative floristic inventory of species according to a pre prepared check in list with 57 taxa, further a detailed exploration of the locality was performed including the measurement of the area (in ha), direct perpendicular distance to the Sázava riverbed (in km), distance of the locality related to the river mileage, proportion of slopes of southern expositions, by means of conservative method using paper maps, calculation of the coefficient of variation of local altitudes (i.e. the assessment of vertical complexity), reading of geographical coordinates by tourist GPS receiver and finally a detailed determination of bedrock types at individual localities. The results were processed and then statistically evaluated in the program CANOCO software for multivariate analyses. The CANOCO program calculated that the influence of species composition in the given areas describes approximately 8.6 % of the total variability of individual species. This influence is proven to be statistically significant on the alpha level = 5%. The analysis, using observed data, calculated that 28.9 % of total variability of the vegetation composition in the studied floristic areas is influenced by the chosen variables. This work may serve as a comprehensive resource of the sites for future research, also it brings a valuable floristic data for the nature conservation purposes.
|
|
|
The archive of the Otava river floods and design of analog-based forecasting method
Vlasák, Tomáš ; Hladný, Josef (advisor) ; Soukalová, Eva (referee) ; Kříž, Vladislav (referee)
(EN): Study of historical flood events is important as a base for hydrological studies, as well as for proposal offlood control measures and real-time flood forecasting helping forecasters to support their decisions. This work deals with proposal of Flood Archive (databa of flood event) and its app|ication in the scope offlood protection ofotava river basin to Písek water gauge. The objective was to pťopose Archive of historical floods containing information about casual synoptical situation, connected weather phenomena (precipitation, temperature) and runoff response. Flood formation mechanism in otava river basin was described using this Archive. A forecasting technique based on analogue method was designed. This technique searches historical records for flood events of similar causes and estimates possible development of runoff response. Archive consists of 72 flood events that occurred between I 890 and 2006 and their peak flow in all cases exceeded given threshold discharge in Písek closin. profile (lO-year return period for 1890-196,l and ,l -year return period for 1961-2006). Available historical data was gathered and processed inÍ.lgraphic form (maps, graphs' tables). F|ood Archive is part of the di ssertation thesis. The most outstanding features of flood formation mechanism in otava river...
|
|
| |
|
|
A proposal of flood geodatabase and its applications for flood control
Vlasák, Tomáš
(EN): Study of historical flood events is important as a base for hydrological studies, as well as for proposal of flood control measures and real-time flood forecasting helping forecasters to support their decisions. This work deals with proposal of Flood Archive (databa of flood event) and its application in the scope of flood protection of Otava river basin to Písek water gauge. The objective was to propose Archive of historical floods containing information about casual synoptical situation, connected weather phenomena (precipitation, temperature) and runoff response. Flood formation mechanism in Otava river basin was described using this Archive. A forecasting technique based on analogue method was designed. This technique searches historical records for flood events of similar causes and estimates possible development of runoff response. Archive consists of 72 flood events that occurred between 1890 and 2006 and their peak flow in all cases exceeded given threshold discharge in Písek closing profile (10-year return period for 1890-1961 and 1-year return period for 1961- 2006). Available historical data was gathered and processed into graphic form (maps, graphs, tables). Flood Archive is part of the dissertation thesis. The most outstanding features of flood formation mechanism in Otava river...
|
|
|
Changes in volume of water reservoir Fojtka due to sediment flux
Vlasák, Tomáš ; Moudrý, Vítězslav (advisor) ; Hradilek, Václav (referee)
Sedimentation in dams is a natural process depending on various factors over a period of time. Sediments influence both total capacity of dam's surface and also relief of bottom.
This thesis deals with amount of sediment in Fojtka dam and with change of its bottom's relief in past 109 years since its establishment. There was conducted measuring using an echosounder in a boat. Final output derived from this experiment was a point layer including 5500 point items. Subsequently there was executed a measurement of dam's shoreline using GPS device. Data were processed in ArcGIS software, then reduced and edited to be used for interpolation tools of ArcToolbox. In order to select the most accurate interpolation method, there were created validation data, which were compared with interpolated data. The best results have been achieved by interpolation method Kriging and TIN in resolution 0.5 m.
Original maps were vectorized for comparison with current condition. Created validation data were compared in order to show accuracy of particular interpolation. The most useful evaluated method for gained data was TIN method in resolution 0.5 m. TIN method was applied in both data sets for 2D and 3D bottom relief visualization and also for calculation of actual water volume and area of water surface of the dam.
Difference in bottom's relief of Fojtka dam showed capacity reduction about 6,7 % and reduction of water surface area about 3,2 %. Regular extracting of sediment in reservoir located above the dam causes this relatively small silting ratio.
|
|
|
Microhabitat preference of male red deer in the Doupov Mts.
Vlasák, Tomáš ; Ježek, Miloš (advisor) ; Kušta, Tomáš (referee)
My work engages problems of microhabitat preference of male red deer (Cervus elaphus). Location of research was occured in the Military Training Area Hradiště on the forest administration district Dolní Lomnice in the Doupovské Mts. Research was conducted using a GPS device. The first part of bachelor thesis is focused on literary analysis as a description, biology, ethology and damage by red deer on the forest stands. The second part of bachelor thesis is research itself. Home range size was calculated from winter and summer habitats. Monitored male red deer prefered visibility to the south. The lowest visibility was found to the west. During the day occurrence of hunting facilities is minimum in winter and summer periods. Greater occurrence of hunting facilities was only found in the night and morning time in the winter. Collected data were analyzed using graphs and tables, which are situated in the final part of this bachelor thesis.
|
|
|
Výzkum metod a rozvoj předpovědních modelů pro potřeby povodňové ochrany: Rozvoj a aplikace hydrologických modelů na předpovědních centrech ČHMÚ
Český hydrometeorologický ústav, Praha ; Březková, Lucie ; Soukalová, Eva ; Dydowiczová, Dana ; Younis, Jalal Hasan ; Kotek, Radovan ; Šrejber, Jan ; Boříková, Lenka ; Kopeček, Pavel ; Vaclík, Luboš ; Vlasák, Tomáš ; Lett, Petr ; Křovák, Michal ; Hančarová, Eugenie ; Řičicová, Pavla
Předpovědní model pro povodí toků horního Labe se závěrovým profilem Přelouč. Předpovědní model pro povodí Jizery a Sázavy. Předpovědní model pro povodí Vltavy po přítok do Orlíka. Předpovědní model pro povodí Berounky mezi Plzní a Berounem. Předpovědní model pro povodí Ohře po profil Louny. Předpovědní model pro povodí Opavy, Bečvy a dolní Odry. Předpovědní model Hydrog pro povodí Svitavy po soutok se Svratkou a pro povodí Svratky po stanici Židlochovice. Předpovědní model MIKE pro povodí Moravy.
|
|
|
Výzkum metod a rozvoj předpovědních modelů pro potřebu povodňové ochrany: Rozvoj a aplikace hydrologických modelů na předpovědních centrech ČHMÚ
Český hydrometeorologický ústav, Praha ; Koštěk, Jiří ; Soukalová, Eva ; Dydowiczová, Dana ; Younis, Jalal Hasan ; Kotek, Radovan ; Šrejber, Jan ; Boříková, Lenka ; Kopeček, Pavel ; Vlasák, Tomáš ; Lett, Petr ; Veverka, Michal ; Hančarová, Eugenie ; Řičicová, Pavla
Předpovědní model pro povodí toků horního Labe po Přelouč. Předpovědní model pro povodí Jizery a Sázavy. Předpovědní model pro povodí Vltavy po Orlík. Předpovědní model pro povodí Berounky mezi Plzní a Berounem. Předpovědní model pro povodí Ohře po profil Louny. Předpovědní model pro povodí Opavy, Bečvy a dolní Odry. Předpovědní model Hydrog pro povodí Svitavy po soutok se Svratkou a pro povodí Svratky po stanici Židlochovice.
|
|
| |
|
|
Výzkum a implementace nových nástrojů pro předpovědi povodní a odtoku v rámci zabezpečení hlásné a předpovědní povodňové služby v ČR: Vytvoření metodiky dlouhodobých pravděpodobnostních hydrologických předpovědí
Český hydrometeorologický ústav, Praha ; Krejčí, Jakub ; Ryglewicz, Michal ; Soukalová, Eva ; Březková, Lucie ; Čekal, Radek ; Štěrbová, Kateřina ; Vlasák, Tomáš ; Daňhelka, Jan
V rámci řešení DÚ 2 byla zpracována literární rešerše. Byla navržena a demonstrována metodika tvorby střednědobé hydrologické předpovědi odtoku s předstihem předpovědi 10 až 30 dnů. Metodika využívá historických dat a stochastického generátoru pro vytvoření sady analogů použitých jako alternativní vstupy srážek a teploty vzduchu v předpovědním období. V následujících letech řešení projektu budou vyvinuty programové prostředky, které umožní rutinní provozování navrženého systému střednědobých předpovědí. Programy budou včleněny do stávajícího předpovědního systému a budou koncipovány jako otevřené tak, aby v některých krocích umožňovaly případné změny nastavení. Příkladem může být princip výběru členů ensemblu. Obecně lze rovněž předpokládat růst úspěšnosti metodiky s množstvím generovaných členů ensemblu. Systém proto bude koncipován jako otevřený právě směrem ke zvyšování počtu variantních předpovědí.
|
guest ::
