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Modeling hydrological response of the catchment to various precipitation events
ŠVANDA, Dominik
This thesis deals with the simulation of the hydrological response of a river basin to various precipitation events. The hydrological response was simulated in the Olešenský brook basin. The outflow of water from the landscape is influenced by many different factors at the same time. Among the most important factors are, for example, the slope of the terrain, land use, saturation of the soil profile withwater, anthropogenic influences, vegetation cover and last but not least the geological and soil conditions, the shape and area of the river basin, climatic conditions etc. explained and described in detail. Several methods are used to calculate the water runoff from the landscape, in which case the CN curve method was used to calculate the direct runoff from the landscape. By using the BPEJ map, land use and maximum daily precipitation totals with a probability of repeating N years (2, 10, 20, 50 and 100 years) obtained from the rainfall station Týn nad Vltavou, calculations were performed first in a numerical (vector) way and then the maps of direct water runoff from the catchment area were created in a raster way performed in ArcMap software. In the next step, various scenarios were simulated that influenced the outflow of water from the catchment. The first scenario was a change in soil saturation with water, resp. water content in the soil (dry, medium and wet). It has been found that the outflow of water from the basin and the peak flow were both fundamentally changed. Second scenario was grassing of all arable land in the basin, where the actual state compared to the theoretical state. This change reduced the CN curve values, what in turn reduced the direct water runoff from the landscape. Third and the last scenario was the concept of 20 metres wide infiltration strips along roads, watercourses and water areas. The proposed measure reduced the runoff coefficient values by about 1 % compared to the runoff coefficients at the actual state. In this case, there was no fundamental change as the strips occupy only a small part of the total area. However, infiltration strips still have a positive effect on rainfall-runoff events in the landscape.
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Event-based rainfall-runoff modelling of the selected river basin
TICHÁČEK, Pavel
This thesis deals with the event-based rainfall-runoff modelling of the selected river basin. This thesis is based on my previous work "Factors affecting the water discharge from the river basin during rainfall-runoff events". In that work I described factors, which have effect on water runoff from the river basin. This thesis was solved on basin of Jílecký stream. Water runoff from basin is affected with a number of factors, the most significant are slope of the terrain, soil saturation, geological and pedological conditions, vegetation cover and anthropogenic influence. Calculations of direct runoff were realised with method of CN curves, with using BPEJ map, land use map gained from Corine Land Cover 2006 and maximum daily precipitation sums with 2, 10, 20, 50 and 100 years probabilities recurrence obtained from the rainfall station Netřebice. Calculations were performed in a numerical method using vector data and a raster method performed in ArcMap. In the next step I performed simulations of various scenarios of change in river basic characteristics such as soil saturation change, grassing of arable land with a slope greater than 12°, grassing of all arable land and enlargement the built-up area in the river basin.
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Analysis of factors affecting the direct runoff
VLASÁK, Ivo
This diploma thesis deals with the analysis of the factors which influence the direct drainage from the drainage area. The thesis specifically deals with the drainage area of the Kopaninský brook. Drainage is always influenced by several factors at the same time. These factors are above all climate, anthropogenic impact, underdrainage, shape and extent of a drainage area, land use, geologic structure, location and altitude of a drainage area. The direct drainage can be separated by different methods (modificated semi-graphical method, GROUND method, method of hydrogram separation, method of digitals filtres) or CN- curves can be used for calculation. This thesis used the method of CN curves to process the results of a given drainage area. In the methodical part of the thesis I reached to the creation of direct drainage maps with the utilisation of the BPEJ maps together with the input data gained by the method of CN curves. These outputs were created at different values of design rains repetition time N= 2, 10, 50 and 100 years. The volume of a direct drainage was calculated by a classic method and by a method using the ArcMap programme. Another part of the thesis was simulation of different area utilisation situations (real condition versus grassing of ploughland) and saturation of drainage area, or more precisely water content in soil (dry soil, middle dry soil, wet soil).
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Factors affecting the water discharge from the river basin during rainfall-runoff events
TICHÁČEK, Pavel
This thesis focuses on the factors affecting runoff water from the basin during the rainfall-runoff events. Work begins by describing the circulation of water in nature and continues with hydrological balance. Next chapter is the formation of precipitation and water runoff, in which the water outflow is divided into surface and subsurface. In the work is characterized runoff process and there are described factors that affect water runoff from the watershed. The last part describes the possibility of using these factors for creating erosion and flood control.
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Analysis of factors affecting a direct runoff from the catchment area
NEUBAUEROVÁ, Andrea
This diploma thesis follows my bachelor thesis. The main purpose of the bachelor thesis was to clarify fundamental terms and to explain the sorting of particular parts of a direct flow that involves both the surface saturated flow and the hypodermic flow. This diploma thesis is focusing on the origin of direct flow in a river basin. Specifically, it deals with river sub-basin P6, P52, and P53, which are located in Kopaninský potok river basin. Furthermore, it deals with Jenín I. and II. river basins and the last analysed is Ostřice river basin (SO2). Factors influencing direct flow are researched on all river basins. It is impossible to say that the origin of direct flow is caused solely by a single factor; it is always the result of multiple factors. Among these factors belongs the atmospheric precipitation, type of soil, vegetation, climatic and anthrophogenic conditions, land use, and inclination of the area. The bachelor thesis explains the issues of multiple methods of flow separation, but this diploma thesis is primarily focused on two methods for calculation of ratio between the direct and the total flow. 1) Empirical method GROUND, which is used to separate hydrographs of medium daily river basin flow. 2) Method of digital filter by Lyne Hollick separate fast and slowcomponents from the overall concentrated flow and are based on the theory od signal analysis. Afterwards, the results of flow separation were compared to the factors influencing the origin of the direct flow. The daily total flow rates for every analysed river basin were used as the input data for calculating the flow separation.
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Direct run-off - formation and separation methods
NEUBAUEROVÁ, Andrea
The bachelor´s thesis occupies with an issue of a direct flow. The main purpose is the explanation of the basic terms of the issue and the explanation of the sorting of particular parts of a direct flow, that involves a surface saturated flow and a hypodermic flow. Subsequently the thesis describes its participation in the hydrogeological cycle, which means the participation in the permanent circulation of a surface and underground water on Earth. The extreme precipitations are dangerous due to their force, total sum and intensity. The inception of hydrological occurrences like floods or dry seasons is possible owing to this. The fallen precipitations have a big influence on a surface flow and a transportation of soil particles. The thesis is focused on the inception and the genesis of a direct flow. Further it focuses on the factors that influence the flow. Among these factors belong climatic and anthrophogenic conditions, vegetation, type of soil and atmospheric precipitations. There are clarified selected methods of potential separation which are explained and described in detail. This part of the issue mentions CN curve method, GROUNG method, MPGM, analysis of dropped subdivisions and finally method of digital filter (Chapman). These methods divides the flow on an elemental flow and direct flow.
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