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Modelling the course of extreme floods in the context of landscape changes and integrated flood protection
Jeníček, Michal ; Langhammer, Jakub (advisor) ; Zezulák, Jiří (referee) ; Szolgay, Ján (referee)
Introduction Floods mean a considerable hazard for mankind. Effective protection against their impact represents one of the basic hydrology and water management tasks. The conception of flood protection came tfuough development reflecting the progress in natural processes description, flood experiences and also improvement in technology possibilities enabling better computation of flood measures effectiveness. Cunently centralized flood protection concept is replaced with íntegrated flood protection concept (Langhammer et al., 2008b; Dumbrovský et al., 2006)' which gives the complex flood protection solution for the whole basin by means of smaller, close{o-natural measures, such as small retention reservoirs. land use change, suitable agrotechnical principles etc. The thesis can be divided into three main parts that form three main pillars ofintegrated flood protection. These pillars are represented by three case studies. First study was made in Blanice River basin. It computes flood extreme changes in condition of changing landscape. Results could lead to positive land cover change which could cause the flood peak decrease. Second study was made in Chomutovka River catchment (Ore Mts.). It quantifies dry retention reservoirs impact on the course of floods by different precipitation extremities. Third study...
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Influence of spatial snow distribution on flood course
Kučerová, Dana ; Jeníček, Michal (advisor) ; Langhammer, Jakub (referee)
For the purpose of hydrological forecasting on mountains' and sub-mountains' rivers is important knowledge of distribution of snow water equivalent in the watershed. Submitted thesis therefore deals with comparison of 9 interpolation methods in terms of quality of their forecasting when predicting snow depth and snow water equivalent in watershed Bystřice (127,6 km2 ), which is situated in the northwest of Bohemia in the Ore mountains. Point data of snow depth and snow water equivalent used in interpolation were sampled during an off- road measuring in 17. 2. 2010 at the 14 snow sampling locations. The interpolation methods were: (1) Thiessen's polygons, (2) inverse distance weighting, (3) global polynomial (4) local polynomial (5) radial basis functions, (6) ordinary kriging, (7) cokriging, (8) residual kriging and (9) orographic interpolation. Independent variable-altitude used in the calculation of snow depth and snow water equivalent was used only in the last three listed methods. Predictive ability of interpolation methods was evaluated by using cross-validation and visual comparison of predicted maps. The best prediction ability was provided by residual kriging and orographic interpolation. The geostatistical methods were next in the order. The method of Thiessen's polygons and inverse distance...
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UAV remote sensing of hydrological processes and fluvial dynamics
Lendzioch, Theodora ; Langhammer, Jakub (advisor) ; Cramer, Michael (referee) ; Hais, Martin (referee)
UAV REMOTE SENSING OF HYDROLOGICAL PROCESSES AND FLUVIAL DYNAMICS THEODORA LENDZIOCH Abstract Using drones and machine or deep learning algorithms (ML or DL) for environmental monitoring offers several advantages over traditional methods, including gathering high spatial resolution data quickly and non-invasively, acquiring real-time data, and covering large and remote areas. This dissertation focuses on snow cover, river granulometry, river sustainability, river bathymetry, and peatland dynamics based on approaches of drone-based imagery that are critical for understanding fluvial processes in mid-mountain regions and their implications for streamflow patterns and ecosystem health. Measuring Snow Depth (SD) and vegetation characteristics like Leaf Area Index (LAI) accurately is essential for effectively predicting snow cover and snowpack persistence across study sites (papers I and III). A further aspect of the fluvial process mediator involves the reproducibility of drone data. This allows for seamless coverage of riverbeds and the determination of ideal parameters for sediment surface cover detection. This can be done through photo-sieving or DL technique, which can analyze Particle Size Distributions (PSDs) of an entire river point bar from top-view UAV images (as described in papers II and V)....
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UAV monitoring of montane peatbogs
Kevešová, Adriana ; Langhammer, Jakub (advisor) ; Lendzioch, Theodora (referee)
This thesis deals with UAV imagery analysis as used to monitor environmental settings, in this case a particularly sensitive ecosystem of a peatbog. The non-destructive aspect of UAV monitoring based on remote access to the studied area is crucial in this scenario. Introduction to the topic, examples of the employment of UAV technologies and the possibilities of their application in monitoring peatbogs are followed by examples of visual data analysis with the help of various software on the multispectral data acquired at peatbog Rokytka in the Šumava National Park. Key words: UAV, monitoring, peatbogs, remote sensing, multispectral imaging, classification
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Extreme hydrological processes in the upper Ostravice River basin
Cermanová, Eliška ; Langhammer, Jakub (advisor) ; Matoušková, Milada (referee)
The main object of this bachelor is the assessment of rainfall-runoff processes with a primary focus on the occurrence of extreme hydrological phenomena in the upper basin of the Ostravice river. The first part of the work is devoted to literature research dealing with the issue of extreme hydrological phenomena and their assessment methods, supplemented by research about current findings regarding changes in the rainfall-runoff regime. This part ends with a description of the physical-geographical conditions of the basin, ilustrated by map outputs. In the second practical part, the available data of average daily flows and daily precipitation totals from the ČHMÚ are analyzed in the period 1970-2020. By Pettit's test of homogeneity, the period is divided into two parts (1970-1995 and 1996-2020) to analyze the change in seasonality of the runoff regime and extreme events. Attention is also paid to the change in the ratio of base and direct runoff using the baseflow index and the runoff coefficient. To detect changes in the characteristics of the frequency of occurrence, duration and intensity of extreme events, the threshold value method and the insufficient volume method were used. As a result, a shift in the seasonality of the occurrence of floods to earlier months and a significant increase in...
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Effect of climate change on hydrological extremes in montane catchments
Čermák, Daniel ; Langhammer, Jakub (advisor) ; Jeníček, Michal (referee)
This master thesis deals with the issue of low-flows in mountain catchments in the context of expected climate change. The Zdobnice, Vydra and Mumlava river basins are selected for analysis. In the first part of thesis, the meteorological and hydrological historical data are evaluated. This data are obtained from CHMI (Czech Hydrometeorological Institute). The work also focuses on estimating the possible change in flow rates in the distant future (2100). For these purposes, the conceptual model HBV is used. This model is often used for these types of analyzes due to its robustness. To evaluate the change, twelve alternative scenarios were created. These scenarious were based on the results of global and regional climate models related to each selected river basins. The model was calibrated using the automatic GAP optimization function. Based on the best results, the calibration period is set for the years 1980 - 1998. Climate models suggest increase of temperature in far future by 1.5 ř C - 4.5 ř C. At the same time, according to climate models, we can approximate a total precipitation change by 10 %. Based on climate changes, a shift in the runoff seasonality in the all river basins is evident. Seasonality change is most visible in the Zdobnice river basin. In terms of hydrological drought, an...
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Detection of the forest disturbance using UAV multispectral photogrammetry
Minařík, Robert ; Langhammer, Jakub (advisor) ; Hofierka, Jaroslav (referee) ; Miřijovský, Jakub (referee)
Epidemic (calamitous) overpopulations of bark beetles (Scolytinae Latreille, 1804) caused by climate change and inappropriate tree species composition currently have the most negative impacts on the development of Europe's mixed and boreal forests. Epidemic overpopulations can significantly undermine forest health and cause economic losses. It is therefore essential to use appropriate methods for early detection of bark beetle disturbance. Multispectral remote sensing (RS) methods using unmanned aerial systems (UAS) represent a new option for contactless landscape monitoring providing quantitative information on vegetation health with high spatiotemporal resolution and therefore appear to be suitable for early detection of disturbance. The thesis focused on the validation of the use of UAS multispectral photogrammetry and image classification methods for the detection of individual forest disturbance stages caused by the spruce bark beetle (Ips typographus Linnaeus, 1758) at the level of individual trees for the study of disturbance dynamics. In this dissertation, all important aspects of detection were elaborated: analysis of the suitability of spectral bands for disturbance detection, radiometric calibration of multispectral cameras, automated segmentation of individual canopies from...
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Analysis of fluvial dynamics of montane stream using UAV
Šolc, Jakub ; Langhammer, Jakub (advisor) ; Hartvich, Filip (referee)
6 Abstract In recent decades the field of fluvial geomorphology has moved towards the most detailed and comprehensive description of the processes in fluvial systems. The recent development of UAVs (Unmanned Aerial Vehicles) has been a major contribution in analysis of fluvial processes, it provides very detailed data for change analysis. This thesis deals with the analysis of recent fluvial dynamics using UAV. The theoretical part of the thesis summarizes the current theoretical and methodological knowledge from the study of fluvial dynamics and also presents the general principles of UAV monitoring with its use in fluvial-geomorfological research. Recent fluvial dynamics was evaluated in the stretch of Javoří brook in Šumava Mountains where the long-term research is conducted by the Department of Physical Geography and Geoecology. Causal runoff events with an impact on fluvial dynamics were identified on the basis of the analysis of hydrometeorological data covering hydrological years from 2016 to 2020. A total of fourteen events exceeded the threshold of channel-forming discharge Q = 5,041 m3 ·s−1 in the investigated period. Geometrical, morphological and volume changes were evaluated based of the photogrammetric reconstruction of the riverbed during three successive scannings (2015, 2018, 2020). The...
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UAV photogrammetry as tool for evaluation of fluvio-morphological changes of streams
Lörinc, Michal ; Langhammer, Jakub (advisor) ; Hartvich, Filip (referee)
This thesis is focused on a use of a technology that is relatively new and popular in geoscience applications, including the fluvial dynamics research. Unmanned aerial vehicles are becoming widely used in numerous geographical subdisciplines due to their capabilities and advantages of UAV imaging in comparison with other remote sensing techniques. These advantages and also limitations together with general characterization of UAVs are summarized in the secondchapter of the thesis. The following theoretical chapters deal with basics of UAV photogrammetry and also evaluate the potential of UAV imaging in fluvial geomorphology. The fifth chapter of the thesis comprises a case study that evaluates the use of an UAV equipped with a non-metric camera for fluvial environment reconstruction. Images of Javoří potok have been processed in Agisoft PhotoScan and ArcGIS to indicate geomorphological changes of the stream channel that happened during a 5 month period from November 2014 to April 2015. Keywords: UAV; photogrammetry; fluvial geomorphology; hydrology; channel
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Impact of stream and floodplain modification on the flood effects.
Rettichová, Zuzana ; Langhammer, Jakub (advisor) ; Matoušková, Milada (referee)
The thesis deals with evaluation of the Volyňka river network modification on the basis of field survey, and identification of critical stream segments, which may influence course of flood events by means of GIS analysis. Two extreme floods took place in the Volyňka river basin in the years 2002 and 2009. The paper evaluates causes, course of events and effects of the floods. To get information about river network modification the HEM-F fiels survey methodology was used. The whole stream of Volyňka river was investigated from its spring to Volyně town, the tributaries in the upper part of the Volyňka river basin and the stream Spůlka. Intensity of stream modificatin and flood effects character were evaluated and critical sections were indentified on the basis of the mapping results. The potential flow obstacles are the most frequent type of critical modification of the stream. Especially the unsufficiently designed bridges, weirs and culverts cause the most intensive damage and geomophological effects of the flood. Individual kinds of obstacles are typical for certain sections of the river flow. Modifications limitating use of retention potential of the floodplain are often present in the central and lower parts of the Volyňka river basin. In several critical stream segments there were proposed...
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