National Repository of Grey Literature 65 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Evaluation of soil coverage with Remote sensing
Kocum, Jiří ; Šefrna, Luděk (advisor) ; Žížala, Daniel (referee)
Title: Evaluation of soil coverage with Remote sensing Author: Bc. Jiří Kocum Study Programme: Master studies in Physical Geography and Geoecology Supervisor: RNDr. Luděk Šefrna, CSc. Soil coverage of Czech Republic is well mapped, especialy thanks to Complex Soil Survey during the 1970s. Results of this survey were digitalized and nowadays they are usefull for many analysis, studies, spatial planning and other administrative needs. Despite their considerable details, they are not capturing many of the non-negligible phenomena, either due to inaccuracies at the time of collecting these data or due to ongoing natural processes, in this case mainly soil erosion. This thesis deals with soil mosaics that are visible from aerial photographs on agricultural land but are not affected in the Complex Soil Survey maps. For this purpose 50 locations in the Czech Republic were selected where mosaics are studied. Attention is paid to the way of origin, places of occurrence and the shape of the mosaic itself. Based on these variables a classification of individual mosaic types was created. The resulting classification consists of 3 groups together containing 9 categories. Not all selected locations contain only one type of category. The mosaic is often made up of several types, and the resulting shape is the sum...
Rate of soil organic carbon sequestration in stone quarries
Plasová, Marie ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
As a result of minerals extraction, anthropogenically disturbed sites are created. In these sites we can study soil development, the rate of pedogenetic processes or the rate of nutrient accumulation. The aim of this thesis is to investigate the rate of sequestration and carbon stock in stone quarry soils in the area of granodiorite quarries near Skuteč, Czech Republic, where the quarries are different in successional age. The material was collected using the method of quantitative sampling with samples of defined volume. In total, 69 samples from 24 sites were collected in defined depths of 0-10 cm, 10-20 cm and the LFH horizon. The successional age varies from 1 year (new level without woody plants) to 84 years (Derková, 2020). The samples were processed to obtain fine earth and then the total amount of carbon (Ctoc) was analysed using mass spectrometer in the Stable and Radiogenic Isotope Research Laboratory at Faculty of Science, Charles University (Flash EA 2000 a TC/EA High Temperature Conversion Elemental Analyzer). Then the dependency between the rate of carbon sequestration, carbon stock and the successional age of the location was analysed using linear regression. The result obtained indicate that the carbon stock increases with increasing successional age, whereas the sequestration rate...
Assessment of the rate of vegetation succession at abandoned stone quarries using dendrochronology
Derková, Nikola ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
Dendrochronology is a reliable method of determining the age of a stand. In this thesis, dendrochronology is used to assess rate of vegetation succession in abandoned granodiorite quarries. There were selected eight localities in the study area, each with several sites. At each site there were four - five optically oldest trees selected, from which cores were taken using increment borer. A total of 79 increment cores were analyzed. The obtained age of trees was compared with known age of abandonment and a sequence of aerial photographs, showing history of sites since abandonment. As the results show, tree vegetation is attached in the area after approx. 3 - 7 years from the end of disturbance. We observe continuous stand in the area after approx. 12 years from the end of disturbance.
The ability of plants to indicate abiotic environmental conditions
Lebedová, Michaela ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
The occurrence of different plant species is influenced mainly by individual environmental factors such as light, heat, soil reaction or nutrient content. The knowledge of the relationships between the plant species and the mentioned ecological factors, allows us to estimate the ecological properties of the habitats in which these species grow without the need of direct measurements. The aim of this thesis was to review the literature on the ability of different plants to indicate abiotic environmental conditions and to verify it on selected soil properties (soil nitrogen and phosphorus content, soil reaction) at sites where both soil sampling and analysis and phytocenological relevés were collected. Tabulated Ellenberg's indicator values were assigned to recorded species from 14 catchments of the GEOMON network. The tightness of the relationship between the indicator values and the measured data was examined in several soil layers defined as: L, FH, 0-10, 10-20, 20-40 a 40-80 cm and phytocenological relevés of different size: A - 400 m2 , B - 40 m2 a C - 4 m2 . The results showed that the data correlated best in the soil layer FH and the strongest relationship was found between the average Ellenberg's indicator values from phytocenological catchments C with an active soil reaction. Keywords:...
Variability of hydropedological characteristics of soil type in the catchment of Tetřívčí brook
Kozáková, Jana ; Kliment, Zdeněk (advisor) ; Šefrna, Luděk (referee)
This thesis deals with the evaluation of hydrological properties variability of soils in forest catchment Tetřívčí brook in the source area Blanice based on selected hydropedological characteristics with respect to soil type, vegetation cover and character of slope. The selected hydropedological characteristics are maximum capillary water capacity, full water capacity, soil infiltration capability - infiltration rate and cumulative infiltration and retention potential of soils. In sum of seven soil subtypes found in forest (coniferous, deciduous and mixed) and meadow (cut and non-maintained) and on the different slope (three categories) were studied in the catchment area. This thesis is built on bachelor thesis, which dealt with the variability of hydropedological characteristics in the experimental pair comparison basins of Tetřívčí and Zbytinský brook. In the thesis were used mainly the measured data obtained from repeated field campaigns in pre- selected sites and data from the database of experimental catchments of Zbytiny. In the selected sites were made soil probes, soil samples were taken using Kopecky cylinders and infiltration measured by a single-cylinder infiltrometer. By laboratory determination and calculation, selected hydropedological characteristics were obtained. The results were...
Pedogenic carbonates of loess-paleosol sequences
Máslo, Jaroslav ; Flašarová, Kristýna (advisor) ; Šefrna, Luděk (referee)
Loess is sediment composed predominantly os silt-size particles. Silt-size particles are transoported mainly by wind. Loess covers 10 % of earth surface. If the loess can be layed for a longer time when the glacials and interglacials alternate, the loess-paleosol sequences are created. Common part of loess and loess-paleosol sequences are pedogenic carbonates, which are particles of CaCO3. There are many types of carbonates, e.g. Calcified root cells. hypocoatings, needle-fiber calcite… Loess-paleosol sequences and carbonates in them are realy useful source of information about paleoenvirnonment. In practicle part of this work the isotopic composition of C and O in pedogenic carbonates from loess-paleosol sequence in Dejvice (Prague) was measured.
Remote sensing as indicator of Soil structure changing
Kocum, Jiří ; Šefrna, Luděk (advisor) ; Vlček, Lukáš (referee)
1 Univerzita Karlova v Praze Přírodovědecká fakulta Katedra fyzické geografie a geoekologie Studijní program: Geografie (Bakalářské studium) Studijní obor: Fyzická geografie a geoinformatika Jiří KOCUM Dálkový průzkum jako indikátor změn struktury půdního pokryvu Remote sensing as indicator of Soil structure changing Bakalářská práce Vedoucí bakalářské práce: RNDr. Luděk Šefrna, CSc. Abstract This thesis is about soil properties, their influence on soil spectral reflectance and Remote Sensing (RS) in pedology. The aim of the thesis is to explain the cause and to estimate the possible future development of the mosaics of local soils, which is visible in aerial photographs, on the selected territory of Kleneč in the Ústí nad Labem Region, by using data from the field survey and RS. Based on the results, evaluate if the methods of RS are suitable apparatus for solving this problem. For this purpose, data from field surveys, aerial and satellite images were collected. This information was compared and evaluated. The results showed a difference in soil properties that cause a different ability to bond water over time. Differnce in water content in soil influence the spectral reflectance of the soil, which is reflected in aerial and satellite imagery in the form of a mosaic. Key words: Remote Sensing, Soil,...

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