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Dynamics and influencing factors of development of gullies in the Kokořínsko
Kašpar, Vít ; Treml, Václav (advisor) ; Kliment, Zdeněk (referee)
Although gully erosion represents an important process of land degradation, only a few studies in the Czechia have quantified the gully erosion rate yet. Because of the complex and nonlinear dynamics, the estimation of the gully erosion rate requires a long term and technically difficult research. However, a recent methodological approach in dendrogeomorphology allows to reconstruct a gully development and assess gully erosion rate. Based on geodetic survey, a detailed mapping of four gullies in the Polomené Mountains was carried out. Subsequently, the gully erosion rate was evaluated by the analysis of 73 exposed roots of broadleaved trees. The first erosion episode was detected in 1981, however, most of the roots were exposed in the last 15 years. Gullies have been forming non-continuously showing median erosion rates between 10.0 to 13.4 mm/year. Even though topographic parameters and land use changes in drainage basin area may affect the intensity of erosion, most of the erosion episodes have been probably triggered by extreme rainfall events. This study exemplifies that intesive gully erosion may occur even on forest soils. Vegetation cover influences a morphology of gully slopes, but its ability to prevent intensive gully erosion is limited. Keywords: gully, erosion rate, exposed roots,...
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Variability of hydropedological characteristics in model catchments of Blanice River headwater area
Kozáková, Jana ; Kliment, Zdeněk (advisor) ; Královec, Václav (referee)
In this thesis are based on the scientific literature defined selected hydropedologic characteristics and is described their impact on motion and amount of water.in the soil and also on the runoff process. In this thesis are quoted methods that can be used for measuring motion and amount of water. Data obtained on several field campaigns and continuous measurement of soil moisture sensors Virrib was processed. Field campaign took place in catchments of Zbytinský and Tetřívčí stream, which are paired comparative experimental catchments. The continuous soil moisture was measured at three places, which differ in their vegetation and soil cover. Data Analysis was concentrate to evaluate soil moisture measured by Virrib, which were compared to soil moisture determined during field campaigns. The continuous soil moisture was measured at three places, which differ in their vegetation and soil cover. The results show that differences and similarities in the vegetation and soil cover greatly reflect on soil moisture. Subsequent comparison of two differently obtained soil moisture should show that the values obtained from Virrib are representative. But comparations of values discover, that in Virrib measurement can be found some inaccuracies. Keywords: hydropedological characteristics, runoff process,...
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Changes of the natural environment in southern Africa
Píšová, Šárka ; Kliment, Zdeněk (advisor) ; Romportl, Dušan (referee)
The diverse region of southern Africa is affected by several changes of the natural environment. This thesis characterizes the region of southern Africa and evaluates the state and development of these natural conditions and environmental problems in four main categories of physical geography - climate, vegetation, soils and water. A literature review is compiled and processed focusing on studies by field experts, which describe the main issues in these categories. Particular problems which the region encounters are described on a global, regional and local scale. The main problems are: changes in temperature and precipitation, land cover change, deforestation, desertification, threats to biodiversity, soil erosion and water availability. Overall, changes of the natural environment in southern Africa are caused by climate change and anthropogenic activity. However, human activities cause a greater impact as a result of their "indirect influence" on climate conditions and "direct influence" on vegetation conditions. Key words: Africa, southern Africa, natural environment, climate, vegetation, soils, water
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Evaluation of historical flood, Sázava River, 1909
Jelínková, Karolína ; Šobr, Miroslav (advisor) ; Kliment, Zdeněk (referee)
This Bachelor thesis deal with the problems of floods on river Sazava. There are described types and characteristic of floods. The thesis sums up methods of historical flood research. It reviews all known floods on Sazava since 1515 up until 2006. While researching these floods, some previous works about Sazava and also historical documents from archives were used. From the found events, the seasonality of floods is made. The floods in 1909 was researched in more detail in the Kacov profile. The cause-factors of the floods and their process are studied closely as is the process of the flood itself. For the Kacov profile, the specific curve was calculated and the flood wave was described. The progression times of the flood were evaluated. Key words: flood, historical flood, Sázava, Kácov, sezonality, 1909
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Analysis and dynamics of the fluvila system of the Roklanský and Javoří brook
Skrčená, Lucie ; Kliment, Zdeněk (advisor) ; Langhammer, Jakub (referee)
This thesis is focused on fluvial dynamics in gravel bed mountain stream. As model basin was chosen Roklanský brook catchment in Šumava mountains, some methods was used on a part of its tributary Javoří brook. We wanted to make an analysis of Roklanský brook catchment by characteristics and course of channel, river floodplain and fluvial erosion and accumulation forms, to find context and factors natural and anthropogenic influenced character and dynamics of the fluvial system. There were used methods based on field mapping channels and fluvial forms, grain size distribution, lidar data, historical aerial photos by 1949 to 2015, bankfull discharge and study old maps and other historical documents from archives. The results show that fluvial system of Roklanský brook has high rate of dynamics. We get known that placement of accumulation and erosion forms relates with longitudinal slope of channel and geological forms. The train of channel changes often, in past according to anthropogenic intervention. In floodplain of Javoří brook is a lot of potential channels. We get known height of water level which causes significant channel changes. Key words: gravel bed streams, fluvial dynamics, field mapping, historical aerial photos, lidar data, bankfull discharge, historical maps, Šumava mountains,...
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Application of UAV for mapping and assessment of flood effects
Vacková, Tereza ; Langhammer, Jakub (advisor) ; Kliment, Zdeněk (referee)
The aim of this thesis is to devise a method for objective classification of floodplain based on spatially accurate data from UAV that allows identification of the fundamental features of floodplain and channel arising from or affecting by the floods activities. Background research is focused on floodplain forming processes; types of flood on our territory and its geomorphological effects, as well as a brief description unmanned aerial vehicle and their applicability in natural science and the flood. Proposed method was carried out on the test section - a part of meander of Javoří stream in Šumava Mountain - then was tested on complex meander belt of the same stream. Proposed method is based on applicability of standard objective classification. Elementary products from photogrammetric analysis - 2D orthophoto and 3D digital surface model - are used as basic input data. Another aim of theses is to discuss applicability of this method for assessment of fluvial form, its limits and potential development. The results indicated that success of classification will increase significantly the involvement of 3D data to classification, which from standard data from the UAV, despite the lack of absence multispectral bands doing a very valuable source of information for mapping and analysis, for example, the...
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Muddy floods phenomenon
Beranová, Lucie ; Kliment, Zdeněk (advisor) ; Mrkva, Luboš (referee)
Muddy floods phenomenon Department: Department of Physical Geography and Geoecology, Faculty of Science, Charles University in Prague Supervisor: doc. RNDr. Zdeněk Kliment, CSc. Abstract: Muddy floods represent a movement of accumulated material from agriculture areas during floods trigerred by heavy rainfall (with intensity that exceed 30 mm/hour). Areas where moody flows occur are typical with steep slopes, loess, thalweg cultivation and growing crops with erosion dangerous. The most intense moody floods occur particularly in central Belgium, France, Netherlands and Slovakia. The moody floods are caused by growing suburbanization, enlarging area of farmland, tamping during agricultural mechanization or transformation grassed areas into cultivated land. Great attention should be paid to measures against erosion because water erosion with heavy rainfalls increase amount of accumulated material, what amplify negative impact of moody flows. The most suitable solution is combination of agrotechnological, technical and organizational measures. The negative consequences of moody floods are e.g. soil degradation, flooding up nutrients, carrying topsoil or transportation of accumulated material into populated area, where high economical and emotional damage may be inflicted. It is necesery to take floods triggered...
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IMPACT OF DRAINAGE CHANNELS ON RUNOFF REGIME IN FOREST CATCHMENT
Kalkus, Jan ; Kliment, Zdeněk (advisor) ; Jeníček, Michal (referee)
The main task of this diploma thesis is to evaluate function of system of open drainage channels and its impact on runoff from Tetřívčí brook forest catchment in Šumava mountains region, upper basin of the Blanice River. Catchment area is only 1,62 km2 and total length of all channels is over 12 km, so it's very important feature of this catchment. The first task was to explore to explore all the channels and set them to the map. Most of used data were measured manually, only precipitation and water level in main stream were measured by automatic gauges. It's not possible to compare results with state without channels, what is the main obstacle for data analysis. Measured channels normally contribute to total catchment runoff by 6 % to 39 %. About 20 % of channel length participate in runoff process in dry periods, in wet periods it can be even 90 % of channel length, what indicates functionality of drainage system. Actual soil saturation in the catchment is very important factor, it's expressed either by index API 5 (based on precipitation) or by groundwater level in 5 measured in separate drills. It's proved by channels responses in well-saturated periods. Runoff in measured channels raises up significantly after even very small precipitations of 1,7 mm. All results are suggesting, that total...
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Trends in the development of runoff and surface water quality in the Blšanka River basin
Šmidtová, Jana ; Kliment, Zdeněk (advisor) ; Matoušková, Milada (referee)
The aim of this Bachelor's thesis is to analyze trends in the development of runoff and selected features of surface water quality in the drainage basin of the Blšanka river. The thesis consists of a research part and a practical part. The research part examines scholarly literature and describes changes in the runoff and water quality depending on climate change as well as changes in the land use. The practical part processes the data from the Blšanka drainage basin from the end of the 1970s until today. The trends evaluated by the Mann-Kendall's test include the development of the average monthly flow rates, the average monthly temperatures from weather station in Žatec and the monthly amount of precipitation from the four stations situated in or near the area of the drainage basin. The practical part outlines the development of selected indicators of water quality in Trnovany. Next, it also evaluates changes in the land use in a specific part of the Blšanka drainage basin between the years 1995, 2004 and 2013. Keywords: changes in runoff, climate change, water quality, land cover, Mann-Kendall, Blšanka TRENDS IN THE DEVELOPMENT OF RUNOFF AND SURFACE WATER QUALITY IN THE BLŠANKA RIVER BASIN
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