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Reliability analysis of embankment dams endangered by filtration deformations
Čejda, Marek ; Baroková,, Dana (referee) ; Fošumpaur, Pavel (referee) ; Říha, Jaromír (advisor)
Subject of the dissertation is a probability analysis on creation of embankment subsoil filtration deformations. Out of the broad topic of filtration deformations, the dissertation is focused at initiation of the process. At this phase, the overlying layers downstream of levee get uplifted, and eventually get breached. The process of downstream subsoil failure probability estimation is formulated using mathematical and statistical modelling. Within the scope of parametrical study the suggested method is applied onto a test environment. Results of the probability estimation are compared with results obtained using Limit state design method. The results of stochastic modelling can be used for improvement of Limit state design method precision.
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Influence of inflow orientation on overflow characteristics over broad-crest
Major, Jakub ; Dušička,, Peter (referee) ; Fošumpaur, Pavel (referee) ; Zachoval, Zbyněk (advisor)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
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Use of selected artificial intelligence methods for finding small watersheds most at risk of flash floods
Ježík, Pavel ; Fošumpaur, Pavel (referee) ; Hlavčová,, Kamila (referee) ; Starý, Miloš (advisor)
In our region, heavy rains may occur virtually everywhere. Nowadays there are instruments to predict these events in sufficient advance, but without precise localisation, which is a problem. Present instruments for searching endangered watersheds are focused on operative evaluation of meteorological situation and actual precipitation forecast processing (nowcasting). The thesis brings quite different approach. Potentially endangered areas are detected with evaluation of long-term statistical variables (N-year discharges and rain characteristics) and properties of specific watershed. The whole issue is handled out of situation of actual danger, this attitude is so called off-line solution. The thesis describes a model based on selected artificial intelligence methods. The model forms the core of final map application. The use of model and final application is supposed to be used in area of preventive flood protection, and related investment decision-making. The model focuses on heavy rains and flash floods.
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Stochastic management storage function of water reservoir using method of artificial intelligence
Kozel, Tomáš ; Fošumpaur, Pavel (referee) ; Zezulák,, Jiří (referee) ; Starý, Miloš (advisor)
The main advantage of stochastic forecasting is fan of possible value, which deterministic method of forecasting could not give us. Future development of random process is described better by stochastic then deterministic forecasting. We can categorize discharge in measurement profile as random process. Stochastic management is worked with dispersion of controlling discharge value. In thesis is described construction and evaluation of adaptive stochastic model base on fuzzy logic, neural networks and evolution algorithm, which are used stochastic forecast from forecasting models described in thesis. The learning fuzzy model and neural network is used as replacement of classic optimization algorithm (evolution algorithm). Model was tested and validated on made up large open water reservoir. Results were evaluated and were compared with model base on traditional algorithms, which was used for 100% forecast (forecasted values are real values). The management of the large open water reservoir with storage function, which was given by stochastic adaptive managing, was logical. The main advantage of fuzzy model and neural network model is computing speed. Classical optimization model is needed much more time for same calculation as fuzzy and neural network model, therefore classic model used clusters for stochastic calculation.
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The probabilistic solution of dike breaching due to overtopping
Alhasan, Zakaraya ; Fošumpaur, Pavel (referee) ; Šoltész,, Andrej (referee) ; Říha, Jaromír (advisor)
Doctoral thesis deals with reliability analysis of flood protection dikes by estimating the probability of dike failure. This study based on theoretical knowledge, experimental and statistical researches, mathematical models and field survey extends present knowledge concerning with reliability analysis of dikes vulnerable to the problem of breaching due to overtopping. This study contains the results of probabilistic solution of breaching of a left bank dike of the River Dyje at a location adjacent to the village of Ladná near the town of Břeclav in the Czech Republic. Within thin work, a mathematical model describing the overtopping and erosion processes was proposed. The dike overtopping is simulated using simple surface hydraulics equations. For modelling the dike erosion which commences with the exceedance of erosion resistance of the dike surface, simple transport equations were used with erosion parameters calibrated depending on data from past real embankment failures. In the context of analysis of the model, uncertainty in input parameters was determined and subsequently the sensitivity analysis was carried out using the screening method. In order to achieve the probabilistic solution, selected input parameters were considered random variables with different probability distributions. For generating the sets of random values for the selected input variables, the Latin Hypercube Sampling (LHS) method was used. Concerning with the process of dike breaching due to overtopping, four typical phases were distinguished. The final results of this study take the form of probabilities for those typical dike breach phases.
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Influence of inflow orientation on overflow characteristics over broad-crest
Major, Jakub ; Dušička,, Peter (referee) ; Fošumpaur, Pavel (referee) ; Zachoval, Zbyněk (advisor)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
|
|
|
Stochastic management storage function of water reservoir using method of artificial intelligence
Kozel, Tomáš ; Fošumpaur, Pavel (referee) ; Zezulák,, Jiří (referee) ; Starý, Miloš (advisor)
The main advantage of stochastic forecasting is fan of possible value, which deterministic method of forecasting could not give us. Future development of random process is described better by stochastic then deterministic forecasting. We can categorize discharge in measurement profile as random process. Stochastic management is worked with dispersion of controlling discharge value. In thesis is described construction and evaluation of adaptive stochastic model base on fuzzy logic, neural networks and evolution algorithm, which are used stochastic forecast from forecasting models described in thesis. The learning fuzzy model and neural network is used as replacement of classic optimization algorithm (evolution algorithm). Model was tested and validated on made up large open water reservoir. Results were evaluated and were compared with model base on traditional algorithms, which was used for 100% forecast (forecasted values are real values). The management of the large open water reservoir with storage function, which was given by stochastic adaptive managing, was logical. The main advantage of fuzzy model and neural network model is computing speed. Classical optimization model is needed much more time for same calculation as fuzzy and neural network model, therefore classic model used clusters for stochastic calculation.
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Use of selected artificial intelligence methods for finding small watersheds most at risk of flash floods
Ježík, Pavel ; Fošumpaur, Pavel (referee) ; Hlavčová,, Kamila (referee) ; Starý, Miloš (advisor)
In our region, heavy rains may occur virtually everywhere. Nowadays there are instruments to predict these events in sufficient advance, but without precise localisation, which is a problem. Present instruments for searching endangered watersheds are focused on operative evaluation of meteorological situation and actual precipitation forecast processing (nowcasting). The thesis brings quite different approach. Potentially endangered areas are detected with evaluation of long-term statistical variables (N-year discharges and rain characteristics) and properties of specific watershed. The whole issue is handled out of situation of actual danger, this attitude is so called off-line solution. The thesis describes a model based on selected artificial intelligence methods. The model forms the core of final map application. The use of model and final application is supposed to be used in area of preventive flood protection, and related investment decision-making. The model focuses on heavy rains and flash floods.
|
|
|
The probabilistic solution of dike breaching due to overtopping
Alhasan, Zakaraya ; Fošumpaur, Pavel (referee) ; Šoltész,, Andrej (referee) ; Říha, Jaromír (advisor)
Doctoral thesis deals with reliability analysis of flood protection dikes by estimating the probability of dike failure. This study based on theoretical knowledge, experimental and statistical researches, mathematical models and field survey extends present knowledge concerning with reliability analysis of dikes vulnerable to the problem of breaching due to overtopping. This study contains the results of probabilistic solution of breaching of a left bank dike of the River Dyje at a location adjacent to the village of Ladná near the town of Břeclav in the Czech Republic. Within thin work, a mathematical model describing the overtopping and erosion processes was proposed. The dike overtopping is simulated using simple surface hydraulics equations. For modelling the dike erosion which commences with the exceedance of erosion resistance of the dike surface, simple transport equations were used with erosion parameters calibrated depending on data from past real embankment failures. In the context of analysis of the model, uncertainty in input parameters was determined and subsequently the sensitivity analysis was carried out using the screening method. In order to achieve the probabilistic solution, selected input parameters were considered random variables with different probability distributions. For generating the sets of random values for the selected input variables, the Latin Hypercube Sampling (LHS) method was used. Concerning with the process of dike breaching due to overtopping, four typical phases were distinguished. The final results of this study take the form of probabilities for those typical dike breach phases.
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Reliability analysis of embankment dams endangered by filtration deformations
Čejda, Marek ; Baroková,, Dana (referee) ; Fošumpaur, Pavel (referee) ; Říha, Jaromír (advisor)
Subject of the dissertation is a probability analysis on creation of embankment subsoil filtration deformations. Out of the broad topic of filtration deformations, the dissertation is focused at initiation of the process. At this phase, the overlying layers downstream of levee get uplifted, and eventually get breached. The process of downstream subsoil failure probability estimation is formulated using mathematical and statistical modelling. Within the scope of parametrical study the suggested method is applied onto a test environment. Results of the probability estimation are compared with results obtained using Limit state design method. The results of stochastic modelling can be used for improvement of Limit state design method precision.
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