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Hydrological Drought in Headwaters of Šumava Mountain
Skála, Vít
This master thesis if focused on the phenomenon of hydrological drought in the Šumava (Bohemian/Black Forrest) region. Hydrological drought is defined on seven hydrological stations (Modrava (CZ), Rejštějn (CZ), Sušice (CZ), Zwiesel (DE), Teisnach (DE), Chamerau (DE), Kalteneck (DE)) during period 1931-1937 and 1949-2014. The aim is in finding suitable hydrological dought indexes and other methods and apply them od the data. Results are compared each other and also are compared with studies that were proceed in non-mountainous region. For hydrological drought evaluation the threshold concept and method according Gumbel 1963 were used and deficite volumes were calculated. Seasonality graphs and graphs for nuber of drought days in hydrological years were constructed, For trends defining, Mann.Kendall and Hisch-Slack tests were used. Hydrological drought sesonality is different on german and czech side, it means effect of exposition towards southwest winds. Hydrological drought is concetrated in autumn at german stations and in winter on czech stations. Number of drought episodes decreases with decreasing elevation. There were found significant decreasing trends in drought episodes occurance in time. Monthly trends aren't so clear. On czech side there is significant decreasing trend in winter months,...
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Runoff régime focusing on hydrological drought in the catchment area of Liboc river
Juha, Ondřej ; Janský, Bohumír (advisor) ; Burian, Alois (referee)
Drought has been a hot topic for several years. Hydrological drought occurs primarily after the previous lack of rainfall. The basin of the Liboc River suffers from significant drought, mainly due to its location in the rain shadow of the Ore Mountains. The first part of the bachelor's thesis deals with literature research, which summarizes the physical-geographical characteristics of the area of interest. This is followed by a comprehensive research of current knowledge about drought and its types, causes and impacts. Furthermore, the precipitation-runoff process focused on local climatic conditions is described. The practical part consists of the own analysis of the obtained data using average daily flows. The dry days method and the insufficient volumes method were applied here. The period 2018-2020, when the drought was most pronounced, was selected for detailed analysis. Key words: runoff régime; hydrological drought; indicators of drought; deficit volumes; threshold limit method; impacts of hydrological drought; Liboc river
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Modelling of runoff changes due to forest disturbances in the Šumava catchments
Švejdová, Klára ; Jeníček, Michal (advisor) ; Šípek, Václav (referee)
Runoff conditions in river basins are heavily influenced by vegetation cover. Changes in the vegetation linked to forest disturbances significantly affect the water balance of the river basin. These changes can be effectively quantified using hydrological models. Therefore, this thesis aims to describe water balance change in forests disturbed by bark beetles and storms. Three model experiments were simulated using the HBV precipitation-runoff model for Roklanský potok, Ptačí potok and Rokytka catchments in Šumava, Czechia. All these catchments underwent significant forest damage after recent disturbance. First experiment used the split sample test method. Calibration was performed separately for the period before and after disturbance, and then simulated for the whole period. The resulting simulated runoffs notably differ from one to the other, which may be caused not only by deforestation, but also by the effects of climate and the characteristics of individual catchments, which also affect their runoff response. The second model experiment was based on changes in vegetation-dependent parameters (melt factor and snowfall correction factor) and analysis of their effect on the simulated runoff. The results did not reveal significant changes in the monitored runoff characteristics. However, this is...
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Hydrological drought in the context of climatic change in the world and in the Czech part of Elbe River basin
Šachová, Barbora ; Kocum, Jan (advisor) ; Janský, Bohumír (referee)
Hydrological drought in the context of climatic changes in the world and in the Czech part of Elbe River basin Abstract The submitted thesis deals with the hydrological drought as one of extreme runoff situations in relation to climate change. Part of this work is a comprehensive research sources to Czech and foreign literature defining the concepts and the development of hydrological drought due to the physical- geographic and anthropogenic factors. Low flow characteristics and methods for defining the drought events are described. Attention is paid to the possibilities of prevention and compensation of negative impacts of drought. Within the second part the presence of low flow in Elbe River subbasins, Blšanka River, Rakovnický Brook and Vydra River, is analyzed. Water deficit is evaluated with regard to the physical-geographic characteristics and the specifics of water resources use. Outline of possibilities to increase the retention capacity of study catchments is given. Key words: hydrological drought, low flow, runoff regime, retention potential, Blšanka River, Rakovnický Brook, Vydra River
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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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Assessment of physical river habitat diversity of streams. Application in experimental catchments of upper Blanice River.
Stříbrný, Martin ; Matoušková, Milada (advisor) ; Šípek, Václav (referee)
The subject of bachelor thesis was to evaluate the diversity of physical habitat, using three methods of hydromorphological survey. Methodologies with different approaches of evaluation have been applied to model basin Sviňovický stream. Detailed assessment describes the downstream changes in individual characteristics. River basin represents a contrast between the upper stream, which is completely anthropogenically influenced and lower stream which is after restoration. The thesis presents the result of a field survey of different methodologies and evaluates the diversity of habitat in different flow conditions. The results of all three approaches are confirmation of positive impact of restoration to the habitat quality and especially the requirement to modify each methodology to local conditions. Longitudinal development of selected hydromorphological parameters have been observed.
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Hydrological drought in the Loděnice basin
Burian, Alois ; Janský, Bohumír (advisor) ; Skála, Vít (referee)
The aim of the bachelor thesis is to analyse of the current situation of the selected basin of Loděnice which has suffered a significant drought in recent years. The first part of the thesis is a literary research which presents drought as a complex phenomenon. The literary research is based on domestic and foreign literature. The thesis describes its genesis, connections with other types of drought, indicators of drought and possible consequences. The research includes physical-geographical characteristics of the area. The practical part is based on the data obtained from the CHMI (Czech Hydrometeorological Institute) and introduces the runoff regime of Loděnice river with a focus on the period of drought in the past and now. Hydrological drought is evaluated using the threshold limit method and deficit volumes. It has been detected that the basin of Loděnice is still under the larger impact of hydrological drought, especially in August and September. Keywords: hydrological drought; runoff regime; deficit volumes; threshold limit method, Loděnice river
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Hydrological Drought in Headwaters of Šumava Mountain
Skála, Vít ; Janský, Bohumír (advisor) ; Kocum, Jan (referee)
This master thesis if focused on the phenomenon of hydrological drought in the Šumava (Bohemian/Black Forrest) region. Hydrological drought is defined on seven hydrological stations (Modrava (CZ), Rejštějn (CZ), Sušice (CZ), Zwiesel (DE), Teisnach (DE), Chamerau (DE), Kalteneck (DE)) during period 1931-1937 and 1949-2014. The aim is in finding suitable hydrological dought indexes and other methods and apply them od the data. Results are compared each other and also are compared with studies that were proceed in non-mountainous region. For hydrological drought evaluation the threshold concept and method according Gumbel 1963 were used and deficite volumes were calculated. Seasonality graphs and graphs for nuber of drought days in hydrological years were constructed, For trends defining, Mann.Kendall and Hisch-Slack tests were used. Hydrological drought sesonality is different on german and czech side, it means effect of exposition towards southwest winds. Hydrological drought is concetrated in autumn at german stations and in winter on czech stations. Number of drought episodes decreases with decreasing elevation. There were found significant decreasing trends in drought episodes occurance in time. Monthly trends aren't so clear. On czech side there is significant decreasing trend in winter months,...
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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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Assessment of physical river habitat diversity of streams. Application in experimental catchments of upper Blanice River.
Stříbrný, Martin ; Matoušková, Milada (advisor) ; Šípek, Václav (referee)
The subject of bachelor thesis was to evaluate the diversity of physical habitat, using three methods of hydromorphological survey. Methodologies with different approaches of evaluation have been applied to model basin Sviňovický stream. Detailed assessment describes the downstream changes in individual characteristics. River basin represents a contrast between the upper stream, which is completely anthropogenically influenced and lower stream which is after restoration. The thesis presents the result of a field survey of different methodologies and evaluates the diversity of habitat in different flow conditions. The results of all three approaches are confirmation of positive impact of restoration to the habitat quality and especially the requirement to modify each methodology to local conditions. Longitudinal development of selected hydromorphological parameters have been observed.
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