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Reconstruction and model of postglacial spread of subgenus Alnus in Europe
Jelenová, Hana ; Barták, Vojtěch (advisor) ; Mandák, Bohumil (referee)
Many paradoxes exist about postglacial tree migration and they dont solve for many European trees. One example is wetland trees subgenus Alnus, which spread across Europe during the last glacial very quickly according to fossil records. The aim of this thesis is detection their migration potential, with the help of empirical evaluation of interpolated pollen data (interpolation method IDW) and a simulation model based on environmental characteristics of the species. The results of interpolated maps are similar to the rate previously estimated speed and the results of simulation model achieve these speeds only by A. incana but with specific extreme environmental conditions. The mason of this may be adapting its seeds to anemochorii because the simulation model confirmed their good potential to spread by the wind. Results of model for A. glutinosa don´t confirm the ability to rapidly spread by the wind and the observed rate must have another explanation. Maybe rivers can explain the empirical spread rate. This suggests visualization of migration lines and river networks.
The model has also been disclosure of environmental properties that are related to migration potential. Within the parameterization of the model is demonstrated, that R0 of A. glutinosa is significantly better than A. incana. But main parameters of anemochory model are terminal velocity and generation time, which is shorter by the A. incana, and therefore is probably able to spread faster than A. glutinosa.
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Uncertainty associated with survey design in species distribution models
Vrabeľ, Matej ; Moudrý, Vítězslav (advisor) ; Barták, Vojtěch (referee)
Properly choosen input data, their form, way of the collection an the following correction as well, are the key factors affecting the accuracy of the more and more popular models of the species model distribution (SDM). A design unfluence of the data to the choosen distribution model of the virtual species has been tested. The General Linear Model (GLM) has been used. Four types of the present-absent collection designs have been tested for a virtual species on the area of the Czech Republic as follows: accidental, systematic, points on the easy accessible areas (near the communications) and the points with the higher concentration of the scientists (an area of CHKO).The TSS (True skills statistics), KAPPA and AUC (Area under curve) have been used to compare the accuracy of the prediction of the models .The points being choosen from the easy to access areas and CHKO had worse results in all of the monitored values than the accidental or the systematic choice of the points from the whole area of the Czech Republic.It results that the data collection mode affects the final accuracy of the species distribution models.
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Image processing techniques for detection of soil features
Trenčiansky, Jan ; Barták, Vojtěch (advisor)
An image processing technique was applied to detect roddon soil features from UK-DMC2 base data. Roddon soil features represent former watercourses in English Fenland, now raised banks with altered soil composition. They can be clearly seen on remotely sensed imagery as bright features in contrast to the darker surrounding peat land. Based on difference in brightness of roddons and surrounding peat soil the Soil Brightness Index (SBI) was applied to detect the roddons. To identify the edges of these features where there is a large spectral contrast a non-directional filter was applied together with an image enhancing technique to better differentiate the roddons form other non-soil features. Understanding the location of roddons will allow adaptive farming practices that account for differences in soil properties, and help optimizing yields.
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Cadastral map visualization using ArcGIS and QGIS
Šilháček, Ondřej ; Barták, Vojtěch (advisor) ; Moudrý, Vítězslav (referee)
The aim of this work is to create a project in ArcGIS and QGIS that is based
on a visualization of a cadastral map in a format for storing vector spatial data:
shapefile. Spatial features contained in the map have correctly set vector
coordinates, but their style, attributes and properties are in default settings. The task
was to configure all the settings to match the style of the cadastral map. The final
project was meant to be used as a tool that can be applied to other cadastral maps
in default settings in order to change their style into the style of the cadastral maps.
Created style was saved as files that contain information about the properties
that were configured in shapefiles, but they do not contain spatial data, only the
information about their location. Shapefiles were styled according to the cadastral
regulation no. 357/2013 Coll. Created project expands possibilities of how cadastral
maps can be browsed and it will be used for potential customers of the Czech Office
for Surveying, Mapping and Cadastre in Prague who will apply for the cadastral map
in shapefiles.
Theoretical part contains characterization of ArcGIS, QGIS, possibillities of
how cadastral maps can be currently obtained and browsed. Also a brief history of
cadastral maps in the territory of the Czech state. As there are no guidelines, which
could be used for the cadastral map visualization, the methodology does not contain
informations about the process of creating the project, but only instructions that
determine how the final project should look like. Results contain detailed
informations about the process of creating the project with all partial steps including
visualization of shapefiles, saving the project and information how to run the project.
At the end of the theoretical part is an evaluation of the user friendliness, pros and
cons and the overall view of the work with used programs in the meaning of
shapefile visualization.
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Modelling potential distribution of invasive plants Indigo bush (Amorpha fruticosa) and Goji berry (Lycium barbarum) in the Czech Republic
Müllerová, Soňa ; Moudrý, Vítězslav (advisor) ; Barták, Vojtěch (referee)
Biological invasions are currently considered to be one of the major threats to biodiversity. Invasive species are introduced species naturalized in regions outside their native range with both ecological and economic impact known from many regions all over the world. In the Czech Republic, vascular plants constitute a major group of invasive species. They are characterized by the ability to adapt, spread and occupy new sites. Early identification of potentially dangerous species constitute a possible way to prevent further spread. This bachelor thesis presents the use of species distribution modelling technique as a tool for assessing invasive potential and predicting species invasions. The aim was to create the model of invasive shrub species Indigo bush (Amorpha fruticosa) and Goji berry (Lycium barbarum) potential distribution in the Czech Republic and explore the significance of each predictor variable including variables derived from digital elevation model. Models were created in the resolution of 100 m using Maxent method based on presence-only data and ten predictor variables including three topographic variables: elevation, slope and aspect. The results show that the most significant variables for both species are elevation, land cover which is the most important one for Amorpha fruticosa, and temperature annual range. Slope variable is significant for Lycium barbarum. Aspect is not significant. In terms of AUC discrimination measure, high values were achived for both species. AUC value for Amorpha fruticosa is 0,961 and 0,906 for Lycium barbarum. However, the realism and quality of the model is significantly influenced by the stage of invasion and also by complexity and accuracy of input data.
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Development of a tool for digital terrain analysis
Rapoport, Daria ; Barták, Vojtěch (advisor) ; Bašta, Petr (referee)
Component of many hydrological applications using digital terrain models is the calculation of flow accumulation and specific catchment area, which are broadly used conceptions in hydrological modelling.
The goal of this diploma thesis was a proposal of tools for calculation of flow accumulation and specific catchment area by Multiple Flow Direction (MFD) algorithm as more appropriate for many hydrological applications then Single Flow Direction algorithm built-in in ArcGIS. The toolset should serve as an educational and research tool at the Faculty of Environmental Sciences, CULS, but not only there.
The theoretical part of the thesis gives examples of digital terrain models applications in general and in hydrology, summarizes basic methods that define flow direction and flow accumulation of surface runoff in grid-based terrain models and their significance for hydrological modelling. Selected methods and their implementations are described in details in methodological part of the thesis. The tools were created in Python language and may be used in ArcGIS interface.
The functionality of the toolset was tested on a coarse-resolution hydrologically correct digital terrain model of basin Moravian Dyje and simulation results has been extensively compared to those produced by Single Flow direction algorithm.
It is suggested that created toolset would be developed further in direction of calculation of additional related terrain attributes (e.g.Topographic Wetness Index), river network extraction with MFD, dealing with flat and sink areas in input DEM, and other flow direction algorithms implementation.
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Do environmental filters improve predictions of species distribution models ?
Gábor, Lukáš ; Moudrý, Vítězslav (advisor) ; Barták, Vojtěch (referee)
Species distribution models (SDM) are widely used tool in biogeography, macroecology and nature conservation. With gradual development, it has become an important means used by, for example, in determining the potentially threatened locations by invasive species, or studying the impact of climate change on biodiversity. With the progressive development it becomes obvious that one of the major factors limiting the species distribution modelling are input data. The presence data are most readily available, but they suffer from an uneven collection, for example, with a predominance of records in easily accessible locations. The aim of this work is to show, that popular climate filtering of presence data input, in order to eliminate uneven sampling, affects the final model in a negative way. For this purpose, there were virtual sorts of different species and different prevalence of recorded occurrences on the territory of the Iberian Peninsula generated. Subsequently, species distribution models with and without climate filters were created by using Maxent. They were evaluated by AUC. The difference between virtual reality, which is presented to the suitability of the virtual species, and the resulting model was tested by paired T test. Comparison of the AUC confirmed that the species distribution models based on climate filtering have better discriminative ability. However, it only points to the skilful work with the selected sample bias that already does not reflect reality. In contrast, comparison of the differences between virtual reality and the models with and without climate filtering using a paired T test shows greater congruence between unfiltered models and virtual reality. Thus it was proved that the climate filtering does not lead to higher validity species distribution models.
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