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Sediment transport control by check dams and open check dams in Alpine torrents / Contrôle du transport sédimentaire des torrents par les barrages de correction torrentielle et les plages de dépôtPiton, Guillaume 08 June 2016 (has links)
Barrages de corrections torrentielles et plages de dépôts jouent un rôle clés dans la protection contre les crues des torrents. Leurs gestionnaires ont pour mission de réduire les risques d'inondations, mais doivent désormais aussi minimiser les impacts environnementaux liés aux ouvrages de protection. Ceci nécessite une meilleure compréhension des effets des barrages de corrections torrentielles et des plages de dépôts sur le transport sédimentaire des torrents. Cette thèse s'inscrit dans cet objectif et se décompose en deux parties. Sa section sur l'état de l'art présente: i) les différents effets des barrages de correction torrentielle sur la production et le transfert sédimentaire; ii) des descriptions des processus hydrauliques et de sédimentation ayant lieu dans les plages de dépôts; et iii) les processus liés à la production et au transfert de bois d'embâcle. Une nouvelle méthode de quantification de la production sédimentaire des torrents complète cet état de l’art.La seconde partie de cette thèse présente le travail réalisé en banc d’essai expérimental. Une première série d’expérience a permis de mettre en évidence un transport par charriage plus régulier lorsque des barrages de correction torrentielle sont ajoutés à un bief alluvial. Une seconde série d’essais a été réalisée sur un modèle générique de plage de dépôt dans l’objectif d’en caractériser les écoulements. Pour cela, une nouvelle procédure de mesure et de reconstruction par approche inverse a été développée. Il en résulte une description des caractéristiques d’un écoulement proche du régime critique, ainsi que des mécanismes de rétrocontrôle entre morphologie et hydraulique pendant la phase de dépôt. / Check dams and open check dams are key structures in torrent hazard protection. Their managers must mitigate flood hazards, but now must also minimize the environmental impacts of these protection structures. This requires to improve the knowledge on the effects of check dams and open check dams on the sediment transport, and this thesis forms a contribution towards this end.The section on the current state of research reviews i) the diverse effects of check dams on sediment production and transfer; ii) descriptions of the hydraulics and sedimentation processes occurring in open check dams; and iii) woody debris production and trapping processes. This state of the art is completed with proposition of new bedload transport estimation methods, specifically developed for paved streams experiencing external supply or armour breaking.Experimental results are then provided. Firstly, flume experiments highlight the emergence of a more regular bedload transport when check dams are built in alluvial reaches. In a second stage, experiments were performed on a generic Froude scale model of an open check dam basin in order to capture the features of laterally-unconstrained, highly mobile flows. A new flow measurement and inverse-reconstruction procedure has been developed. A preliminary analysis of the results describes flows that tend toward a critical regime and the occurrence of feedback mechanisms between geomorphology and hydraulics during massive bedload deposition.
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Návrh cestní sítě v komplexní pozemkové úpravě / Proposal of road network for complex land adjustmentFLORIÁN, Ondřej January 2015 (has links)
The main purpose of this thesis was compiling the detailed literature search containing the description of a road network from the historical development point of view, detail characteristics of lane types used in complex land adjustment and the evaluation of the road and lane network as a possible element of erosion control. The main object was the analysis of the road and lane network changes during several historical periods, in which the network was captured, studied and the results were compared. The possible causes of the changes where described for key moments of the historical development. As the location of interest the cadastral area Nakri in Ceske Budejovice district was chosen. For this location the detailed road and lane network analasys shows clear overview of remarkable changes during historical development. A part of this thesis is not only capturing the changes, but also a proposal of resolved complex land adjustment, which is in compliance with latest requirements for proposing a plan of common facilities.
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Erozní ohrožení půdních bloků s vybranými plodinami a návrh vhodných protierozních opatření / Erosion danger of soil blocks with selected crops and recommendation of suitable cultivation against erosionJIRSOVÁ, Monika January 2014 (has links)
This thesis deals with different types of soil degradation under the conditions in the Czech Republic. The first part is focused on the evaluation of the causes and course of degradation of soils in the present time. Among the most serious degradation factors may be included the following: pedocompaction, dehumification, land appropriation, bad infiltration, water and wind erosion. In the Czech Republic, only water erosion alone threatens 42% of all agricultural land. In the thesis organisational, technical and agrotechnical anti-erosion control measures are summarised. Their utilisation, efficiency and sophistication are also described. In the next part of the thesis there are six specific land blocks in the same farm in South Bohemia presented. Each of these blocks has a different acreage, the average slope, the crops cultivated and different representation of strongly threatened and moderately erosion-threatened vulnerable areas. The thesis evaluates the number of plants per 1 sq. m, the condition and density of the growth due to the erosive threat to all of these localities.
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Uplatnění meziplodin jako stabilizujícího prvku v protierozní ochraně / Application of catch crops as a stabilizing element in erosion protectionKREBSOVÁ, Lenka January 2014 (has links)
The aim of this work is to determine the effect of the application of catch crops in crop rotation in the cadastral territory Vrábče in Czech Budweis. Erosion washing away from the land is calculated using the USLE, also compared washing off using conventional crop rotation and intercropping with the application process. Analyze here the influence of intercropping to increase anti-erosion effect of vegetation cover. The resulting values of erosion are transported using erosion of crop rotations with intercropping significantly reduced.
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Posouzení efektivity protipovodňové a protierozní ochrany malých povodí / Assessment of erosion and flood control measures effectiveness in small catchmentsFeltl, Jakub Unknown Date (has links)
Thesis is about assessment of erosion and flood control measures effectiveness, especially of broad base terraces. The main contribution is a new method of flood effect evaluation of these measures. This is solved by modern programs and geospatial technologies such as ArcMap and HEC - HMS. Economic assessment in alternative solutions of flood and erosion control effect is a main result which leads to optimal technical proposal. The proposed, relatively fast, method can be successfully applied in practice.
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Vliv uspořádání krajiny na erozní a odtokové poměry povodí / Influence of the landscape management on erosion and runoff conditions of the catchmentHájek, Daniel January 2016 (has links)
Aim of this study is to evaluate the effects of landscape structure on soil erosion and runoff conditions of given area with help of digital elevation model and relevant GIS data. Analyses of soil erosion by water and runoff were processed for current conditions and several other variations. Based on this analyses and results was performed an evaluation of all model variations.
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Stochastic Prediction of Sediment Yields from Strip Mine Spoils of the Arid SouthwestAuernhamer, Mark E., Fogel, Martin M., Hekman, Louis H., Jr., Thames, John L. 16 April 1977 (has links)
From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / Mathematical simulation of the erosion process is accomplished by using a time series of hydrologic parameters as inputs into a modified form of the Universal Soil Loss Equation. A parameter to account for antecedent moisture conditions was found to improve the predictive success of the Universal Soil Loss Equation. The simulation predicts sediment yield resulting from a stochastic sequence of precipitation events on an experimental watershed. This sediment model will be used as a component in a larger, more complex hydrologic simulation model which can be used to determine optimum reclamation practices for the strip mined areas of the arid Southwest. Data from regraded strip mine spoils at the Black Mesa of Arizona are used in calibrating the model.
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Sediment removal from urban runoff using seep berms and vegetative filtrationHamade, Firas Nadim 13 January 2014 (has links)
Previous field demonstration projects in metro-Atlanta have shown that seep berms, which are elongated sedimentation basins at the outlet of a disturbed land area, can provide high suspended sediment trap efficiencies with respect to coarse sediments on construction sites having drainage areas greater than five acres. Previous literature has shown that vegetative filter strips are efficient traps for fine suspended sediment in stormwater runoff. A combination of a seep berm and vegetative filter in series was studied in this thesis as an erosion control measure with quantification of its flow resistance and sediment removal efficiency. First, a field demonstration project was implemented to evaluate seep berms as a viable erosion control measure through a side-by-side comparison with the more commonly-used silt fences on construction sites with drainage areas less than five acres in metro Atlanta. High suspended sediment trap efficiencies were recorded for the seep berm on two separate sites, and the seep berm was shown to be superior to silt fences with respect to sediment control in the site runoff. Then a vegetative filter was studied in the laboratory in a specially-built flume for that purpose. The relationship between vegetative drag coefficient and various parameters reflecting flow conditions and vegetation density in steady, uniform open channel flow was studied in the flume. Both rigid, emergent vegetation and submerged, flexible vegetation were studied at two different plant densities. The application of porous media flow concepts to open channel flow through vegetation resulted in a collapse of data for vegetative drag coefficient for the various vegetation types and densities into a single relationship when plotted against vegetative stem Reynolds number. Point velocity and turbulence intensity profiles at different locations in the vegetative filter were recorded with an acoustic Doppler velocimeter to observe the turbulence structure of the flow and its effects on vegetative drag and settling of sediment. A sediment slurry consisting of a suspension of fine sand was fed into the flume, and an automated sampler was used to measure suspended sediment concentrations along the vegetative filter length for a series of discharges from which sediment flux and trap efficiency could be determined. Experimental data for trap efficiency were plotted against a dimensionless settling efficiency for each type of vegetation and density. These relationships, along with the one developed for the coefficient of drag, were applied in a numerical design technique that allows designers to determine the flow depth, velocity and trap efficiency of a vegetative filter of known dimensions for a given flow rate, sediment grain size distribution, slope, and vegetation density. In a typical design example, the combined trap efficiency proved that a seep berm followed by a vegetative filter can be a very effective erosion control measure.
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Řešení protierozní ochrany na modelovém projektu komplexní pozemkové úpravy / Solution erosion protection on a Complex Land Consolidation modelSVOBODOVÁ, Pavlína January 2013 (has links)
The aim of this work is to explore the area of the Complex Land Consolidation Poněšice in the view of the pedology, hydrogeology and climatology. Further make a erosion threat calculations using the USLE and Curve Number method and afterwards review the application of the erosion control measures in another section of the chapter Main terriorial systems. In conclusion, to estimate the economic aspects of the proposed measures.
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Řešení protierozní ochrany na modelovém povodí matematickým modelováním. / Solution of erosion protection at the model basin using mathematical modelingKŘÍHA, Jan January 2010 (has links)
The contents of this thesis is an examination and assessment of erosion processes in the catchment Budského stream. The area of interest falls into three cadastral territory, Malče, Besednice a Soběnov. Catchment area is 7.1 km2. Integral part of work is the pedological and hydrological research. It was evaluated the impact of waste in the surrounding villages. In the catchment basin, has a significant influence Besednice reservoir. It was assessing its impact on the environment and erosion control functions. Using the acquired information has been calculated N-year water and the amount of drifted soil by Wischmeier and Smith. Another goal is to process this data using software modeling and evaluate output. Against this background and the results are recommended measures to reduce soil loss from these plots.
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