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Mapping relict arctic-alpine tundra vegetation from multitemporal LiDAR data
Šrollerů, Alex ; Potůčková, Markéta (advisor) ; Lysák, Jakub (referee)
The thesis focuses on metrics of vertical structure of vegetation derived from UAV LiDAR data and their use for multitemporal classification of selected species of arctic-alpine tundra in the Krkonoše Mountains. The metrics are selected based on a literature search focusing on low and shrubby stands. Random Forest algorithm and permutation feature importance, drop column importance and individual predictor performance is used to determine the suitability of metrics for distinguishing tundra vegetation. Subsequently, a fusion with multispectral data is performed and influence of the LiDAR derived variables on the refinement of classification results is determined. The use of metrics derived from a digital surface model obtained by image correlation of multispectral data is also examined. Maximum height followed by minimum height, canopy relief ratio and coefficient of variation yielded the best results, they achieved an overall classification accuracy of 67.3% for Bílá louka meadow and 62.3% for Úpské rašeliniště bog. Fusion with multispectral data led to an increase in overall accuracy up to 2 %. In case of vegetation structure derived from the digital surface model, similar results were achieved apart from higher stands. LiDAR data did not prove to be beneficial in distinguishing grass communities...
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Use of current and historical geospatial data for 3d modeling of hradec králové in different time periods
Šrollerů, Alex ; Laštovička, Josef (advisor) ; Štych, Přemysl (referee)
Use of current and historical geospatial data for 3D modeling of Hradec Králové in different time periods Abstract This bachelor's thesis is mainly focused on historical and current geospatial data and the basics of three-dimensional city modeling. It provides an overview on basic methods, data and software suitable for 3D city modeling in different time periods and possibilities of 3D visualization. The practical part describes the process of creating a 3D model in different time periods, namely the cadastral area of Hradec Králové in the years 1840, 1912, 1952 and present. The model consists of terrain interpolated from ZABAGED contour lines and buildings extruded from vector footprints. Subsequent manual modeling took place in SketchUp CAD software. Historical large-scale maps, contemporary orthophoto and OSM are used for this task. The model is visualized using flyby animations, view scenes, interactive browser and presented on a self-created web page and StoryMap JS. Keywords: 3D model, SketchUp, buildings, DTM, historical data.
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