National Repository of Grey Literature 6 records found  Search took 0.00 seconds. 
Possibilities of use of new bathymetry method of water reservoirs
Kundratová, Františka ; Roub, Radek (advisor) ; Hradilek, Václav (referee)
It is essential to measure water depths of rivers, water reservoirs, ponds and lakes from various reasons like hydrologic modeling, monitoring of biotopes, monitoring of sediments or archeologic researches. Hence, the bathymetry techniques for measurements of shallow waters are still evolving. The goal is to find the best method allowing fast and economic mapping of large-scale areas and providing high-resolution data. Currently, the most common method in Czech Republic is probably depth measurement by an ADCP devices, which is a very accurate method, but still time-consuming. On the other hand, airborne laser scanning with wavelength of 532 nm (green laser pulse) has a great potential for shallow water mapping. This work is focused on the possibilities of use of the airborne laser scanning for bathymetry of rivers and water reservoirs in conditions typical for Czech Republic. The methods of obtaining the bathymetric data are discussed in theoretical part, as well as principles of its operation. In the practical part, two study areas (a part of Vltava river and a Hracholusky dam) were scanned using the laser scanner Riegl VQ-880- G. Digital terrain model (DEM) was created from acquired data of the two study areas. After that the DEMs were compared with DEMs which were created from sonar data. The results of comparison are presented. The aim of this work is to assess the ability of airborne laser bathymetry in conditions typical for Czech Republic and verify the accuracy of this method. This method saves time and economic costs and it has great potential to be usable for future research.
Geometric and Terrain Characteristics Modelling and Flowpath Determination in Litovicko-Sarecky potok River Basin
Prágr, Vítězslav ; Bašta, Petr (advisor) ; Hradilek, Václav (referee)
This thesis deals with the examination of morphometric characteristics and flow channels for river basin Litovicko-Šárecký potok in the GIS enviroment. The first part describes the concepts from geometry and terrain characteristics of the basin and their methods of calculation in GIS enviroment and beyond. This includes a description of a digital terrain model and to construct him the most commonly used interpolation methods. Identified characteristics of the basin and flow channels serve to evaluate the systém of small water reservoirs and locations of potential clogging. For this assessment will be used dataset ZABAGED and a second, more accurate DMR 5G.
Bathymetry on the small water reservoir Velky rybnik in the basin of the Litovicko - Sarecky stream
Zvonárová, Eva ; Bašta, Petr (advisor) ; Hradilek, Václav (referee)
The most important part is to perform measurements of selected water reservoirs in Litovicky - Sarecky stream. Selected small water reservoir is Velky rybnik, also called Dolejšak. The measurements were performed RiverSurveyor M9 device, and data were processed using the ESRI ArcGIS Desktop to a digital model of the terrain relief, which evaluates the clogging reservoirs in different places. This clogging is life threatening in the reservoir, but also around the water reservoir. The theoretical part contains the theme of small water reservoirs, their division and various applications. Then describes the methods of bathymetry, digital terrain relief model and interpolation and its methods. The methodology of bachelor thesis is processed measuring and finally in the results evaluated throughout the measurement. At the end of the work is the discussion and conclusion which will propose solutions to this problem.
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.
The impact of small water reservoir on soil moisture in Litovicko-Šárecký brook basin
Kovář, Martin ; Hradilek, Václav (advisor) ; Jačka, Lukáš (referee)
Currently, when there is a reduction of soil water due to drought, is appropriate measure to start systematic collection of data on soil moisture. In this work the soil moisture content was measured on the Litovicko-Šárecký brook basin near a small water reservoir Strand. The datat were collected by direct method, which mean direct soil sampling and subsequent analysis, and indirect methods concretely gathering data by TMS datalogger. Measured data from direct and indirect methods are essentially agree in this, that small water reservoir Strnad hasnt effect at soil moisture in a distance 200 m. The last part describes the analysis of grain soils using aerometrical methods. The resulting soil types are further used for calibrating the TMS datalogger.
Bathymetry of the small water reservoir Kalý rybník in Litovicko-Šárecký brook basin
Burda, Jan ; Hradilek, Václav (advisor) ; Bašta, Petr (referee)
This thesis deals with a measure bathymetry small water reservoirs Kala in the basin of Litovicko-Šárecký brook using a measuring instrument RiverSurveyor M9, and evaluation of measured depths in the form of a digital terrain model of the reservoir floor and the determine the accumulation of the small water reservoir. The theoretical part deals with small water reservoirs in general, ways of clogging and bathymetry. It also describes the location of interest small water reservoir Kala. There are also describes the interpolation methods and a digital terrain model. Included are basic information about the measuring instrument RiverSurveyor M9, which were measured. In the practical part describes the procedure for measuring of the reservoir floor. Furthermore, it is processed by a digital terrain model, including an evaluation of reservoir accumulation. For the creation of a digital terrain model is used several interpolation methods, which are then compared to each other. Among the comparison methods include IDW, Kriging, Topo to Raster, Spline, and Natural Neighbourhood Trend. Have proven IDW method that achieves the best results.

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