National Repository of Grey Literature 50 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
An anthropogenic transformation of the natural sphere of Africa
Píšová, Šárka ; Romportl, Dušan (advisor) ; Kliment, Zdeněk (referee)
Africa is a heterogeneous environment that is affected by natural and anthropogenic processes. This thesis uses a review method to characterize the natural environment of the continent, present possible classifications of natural conditions and to describe the transformation of this environment. The main methodological aim of the thesis was to determine areas threatened by biodiversity loss due to anthropogenic pressures based on a new classification of the natural environment on a continental level. This was executed by methods of environmental stratification and subsequent environmental classification. Thus, this thesis presents a classification of the natural environment on the basis of homogenous units determined by bioclimatic variables and terrain, which are subsequently related to the biodiversity of birds, amphibians and mammals and to an anthropogenic influence represented by anthropogenic biomes. Finally, the share of protected areas is executed in relation to this anthropogenic transformation of the natural environment. Therefore, the thesis is quite a unique approach, as it takes into account a combination of both physical and socio-economic factors at a continental level. The final output consists of a map of the anthropogenic transformation of Africa's natural environment in the...
Influence of soil matter and different land cover on the runoff process (experimental research in the paired catchments Zbytiny)
Královec, Václav ; Kliment, Zdeněk (advisor) ; Kulhavý, Zbyněk (referee) ; Černohous, Vladimír (referee)
The doctoral thesis deals with the evaluation of influences of causal factors that significantly affect runoff processes in landscape. The research is mainly focused on the examination of land and soil cover impacts and partially pays attention to the effects of surface drainage and snow cover. The main effort was to find out the extent of influences of each individual factor on runoff from a different type of landscape. In order to find the correct answer, a methodical approach was applied to small experimental paired catchments where the research has been continuously undergoing since the year of 2006 (the presented results have been collected for 11 years of observations). The small experimental paired catchments are located at the foothills of the Šumava Mountains and they represent small area neighbouring catchments of similar physical-geographic and hydrographic conditions. The catchments were selected as the comparative ones where the main differences are the landscape and soil cover. Moreover, the character of surface drainage is regarded to be an important variable. In the catchment area of the Zbytinský Brook, there predominates the grassland which is largely drained by the subsurface drainage system. In the catchment area of the Tetřívčí Brook the dominant cover is formed by the forest...
Changes of erosion risk and water soil erosion intensity in the Odlezelské Lake catchment
Pagáč, Petr ; Kliment, Zdeněk (advisor) ; Chuman, Tomáš (referee)
Water erosion in the Czech Republic is the largest phenomenon that degrades and seriously damages agricultural areas throughout the country. It is influenced by many factors that have changed since the 1950s. Various methods are used to assess the intensity of erosion. In the Czech Republic, the USLE (Universal Soil Loss Equation) is the most widely used equation, which is the cornerstone of the model used in this work. I quantified and localized water erosion in the Odlezel lake basin for individual scenarios of land use change using the WaTEM / SEDEM model. The results show the seriousness of water erosion in relation to landscape management, as the modeled intensity of erosion in 2018 is almost the same as in the period of collectivization. The results of modeling are confronted with changes of individual input factors, with measured data of river sediment export in the Mladotický brook and up to date knowledge about clogging of the lake basin. Key words: water erosion, modeling erosion, WaTEM/SEDEM
Hydrological drought in headwater areas of the Ore Mountains
Vlach, Vojtěch ; Matoušková, Milada (advisor) ; Kliment, Zdeněk (referee)
Changes in the hydrological cycle are one of the expected impacts of climate change. Until recently, Central European mountain ranges have not been considered to be affected by water scarcity. Nevertheless, recent years have suggested an increasing risk of drought occurrence also in these regions, which have a major impact on the water supply to rivers that drain them. The master thesis deals with the evaluation of hydrological drought in the headwater areas of three catchments in the Ore Mountains for the period from 1967 to 2018. The main aim is to compare the of hydrological drought characteristics in the catchment areas of upper Svatava River, upper Rolava River and Načetínský brook based on available hydrological and climatic data. In connection with this, the work aims to detect the long-term trends of drought occurrence in selected basins. Furthermore, the emphasis is given on the evaluation of natural conditions, especially the historical and current land cover changes in the study catchments. The results point to a significant change in the seasonality of the occurrence of hydrological drought in the second half of the studied period, when the streamflow deficits concentrate between August and October. Furthermore, increasing trends in deficit volumes were found in the catchment areas of...
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...
Rainfall-runoff relations in the Klabava catchement
Kadeřábek, Michal ; Šobr, Miroslav (advisor) ; Kliment, Zdeněk (referee)
This thesis deals with rainfall and water runoff regime in the catchment area of river Klabava. The aim of this thesis is to find changes in the rainfall-runoff regime during the period of observations (1950-2014) and if so, were these changes caused by climate changes or human activities. The research part includes description of rainfall-runoff process and Klabava catchment area description. In the applied part there is an analysis of precipitation - runoff regime for long-term time series of average and minimal annual, monthly and seasonal discharges and annual, monthly and seasonal precipitations using single and double mass curves and statistical tests testing absolute homogeneity, relative homogeneity and trend (by Mann-Whitney-Pettit, Alexandersson, Mann-Kendall tests). The tests were performed by freely available software AnClim designed for these purposes. Mann-Kendall test was performed by MULTMK/PARTMK available as a MS Excel macro for free. Plus, there is basic discussion of floods in Klabava river basin and flood seasonality. The homogeneity tests haven't found many changes at all, most of the detected changes concern the minimal runoff time series. The precipitation annual amount was detected with a raising trend, while the runoff time series seem to have no trend at all. Achieved...
The influence of changes of land cover on connectivity of fluvial processes in catchment
Kofroňová, Jitka ; Langhammer, Jakub (advisor) ; Kliment, Zdeněk (referee)
The connectivity of fluvial processes or hydrological connectivity are terms often used to describe internal linkages in landscape that intensify/reduce water and sediment fluxes as well as the substances they contain. It is based on the concept of landscape connectivity defined, in particular, by fragmentation of landscape and barriers that obstruct the movement of material. While researches focusing on water erosion or runoff focus on the volume of different fluxes, connectivity reveals new information on catchment functioning as well as reactions to various types of stimuli, and thus represents a more complex phenomenon. This master thesis informs about the topic as a whole, it describes the main forms of its modelling and specific influences that have major impact on presented results. Three approaches of modelling were tested. The main concept lies in evaluation of the index of connectivity, firstly, with approach proposed by Borselli et al. (2008) and implemented in software ArcGIS and secondly, in software SedInConnect 2.0. The third approach is modelling connectivity in software LAPSUS 5.0 that belongs to landscape evolution models. Modelling in LAPSUS proved that using even this indirect method for evaluation of hydrological connectivity is a suitable approach. Selected area for modelling...

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