Global ETD Search

11	A Hydrological Framework for Geo-referenced Steady-State Exposure Assessment in Surface Water on the Catchment Scale Wissing, Jutta 30 September 2010 (has links) The major benefit of geo-referenced exposure modelling tools is the provision of spatially distributed information on expected environmental concentrations. This allows for identifying local and regional concentration differences in the environment which facilitates the development of efficient mitigation strategies. Predicted substance concentrations in the environment are governed by emission rates and representation of the substances' transport and transformation processes on the one hand and by the description of the spatial environmental heterogeneity and temporal variability on the other hand. The shape of river basins and streamflow variability within them is a product of physiographic and climatic factors like e. g. topography, land use, precipitation, or evapotranspiration. These factors are very variable in space and time. This heterogeneity in river basins may have an impact on surface water concentrations of various substances. In this work a hydrological framework for geo-referenced exposure assessment in river networks has been developed which predominantly addresses spatial heterogeneity of river basins. The theoretical background for parameterising a river network for the application of GREAT-ER (Geo-referenced Regional Exposure Assessment Tool for European Rivers) is elaborated and implemented. Quantity of discharge, flow velocity of river water and depth of river bed have to be determined at any location in a river network for the representation of substance dilution, transport and degradation. Temporal variability is handled by a probabilistic approach which demands choice and parameterisation of probability distribution functions to describe the river network characteristics. It is substantiated that discharge and its variation can be described by a lognormal probability distribution. This distribution can be parameterised by spatially distributed information on effective precipitation and specific low flow discharge from the German Hydrological Atlas. Geoprocessing methods are applied to couple information from these maps and the river network. Evaluation of discharge probability distributions by means of gauging data demonstrates good agreement. River depth and flow velocity are estimated on the basis of spatially distributed river structure data and therefore account for actual river morphology more than former approaches do. A comparison with hitherto used flow velocity and depth estimation shows significant differences which trigger perceivable differences in surface water concentration estimates. Identification of the sensitivity of hydrological parameters in terms of chemical fate estimation attaches importance to spatial explicit consideration of river networks. The main benefit of the presented methods is comprehensive incorporation of geo-referenced river basin characteristics into the data basis for the GREAT-ER model because this provides the basis for successful prediction of surface water concentrations by GREAT-ER. geo-referenced model GREAT-ER streamflow catchment hydrology flow velocity river bed depth flow duration curve ddc:500
12	České Budějovice- město a voda / České Budějovice- town and water NOVÁKOVÁ, Barbora January 2012 (has links) The thesis deals with the characteristics of the town of České Budějovice focused on the hydrological situation, the coexistence of the town with water and the use of water surface areas. The thesis is divided into two main parts. The theoretical part summarises firstly, the information dealing with geographical physics secondly, socioeconomic information. It is followed by a detailed analysis of the main rivers, the Vltava and the Malše, which flow through the monitored territory. There is also a chapter aimed at the system of ponds in the defined location. From a historical point of view there are mentioned mainly interventions of nature itself in the life of the town in the chapter dealing with floods. The second application part includes the historical analysis of the evolution of the river bed and the water surface areas in the territory of České Budějovice, which was made up on the basis of comparing maps and information from the beginning of the 18th century up to the present. The anthropogenic activity and its influence on the town of České Budějovice itself is presented in the section solving the endangered water surface areas. This part also contains a case study dealing with the possibility of solving these hazards and risks in the countryside. The output of the thesis also includes the creation of promotional materials, which could be used as teaching supplementary materials at primary schools.
13	Sledování a zaměření případných změn říčního koryta vodního toku Ostřice. / Tracing and surveying of accidental changes of the river bed of Ostřice. KUBÁT, Michal January 2009 (has links) The work is focused on monitoring and detail survey of eventual changes in Ostřice river bed in Horní Planá cadastre area. It was done in two phases in different seasons. The work objective is to outline and secure position of cross sections on the sides of the river polygon, followed by their survey. The work consists of two sections {--} theoretical and practical. The theoretical section first explains establishment of a dot field by geodetic points. This is followed by description of a detail dot field, requirements for the individual points, methods of their survey, detail mapping of these points as well as establishment of water stream lengthwise sections and cross sections. The practical part includes characteristics of the surveyed location. In addition there is description of preparatory work, necessary for land survey and the survey itself, using both existing and newly established points of the dot field. At the end there is explanation of auxiliary and detail points calculation and method of their graphic processing. The conclusion includes assessment of changes between April and August surveys of the subject territory.
14	Tlumení energie proudu vodním skokem v prostoru rozšíření koryta / Hydraulic Jump Energy Dissipation in the channel extension Pospíšil, Radek January 2020 (has links) The diploma thesis is focused on the evaluation of the suppression of supercritical current energy in the area of the river bed extension. The hydraulic model was used to simulate current conditions for different variants of river bed arrangement. Individual variants were then evaluated according to the relevant criteria and compared with each other. Results can be applied in hydrotechnical practice based on model similarity.
15	Obnova vodní nádrže v obci Žďárná / Renovation of a water reservoir in the village of Žďárná Pastorková, Nikola January 2022 (has links) The theme of this diploma thesis is to restore the existing small reservoir in the village Žďárná. A new safety spillway and bottom outlet will be built, the flood will be shaped according to the cross-sections and the dam of the water reservoir will be fortified. The designed objects will be hydraulically verified. Using the HEC-HMS program, a hydrological model of the river basin is created and subsequently a derived flood wave PV20.
16	Ghost Water Exhibition Sharp, Michael G. 01 March 2017 (has links) The Ghost Water exhibition of artworks by Michael Sharp was comprised of four main works titled: 30 x 60 Minute Grid Series, Suspension, History/Prehistory, and Lake Bonneville Remnants. The artwork was created as a reaction to the land that once held the prehistoric Lake Bonneville and to its current remnant Great Salt Lake. The work explores the dialogue between absence and presence. Great Salt Lake Lake Bonneville Red Rock Pass Stockton Bar Old River Bed Steep Mountain Long Divide The Threshold Utah the West Great Basin Bear River Weber River Jordan River desert salt asphalt water railroad glass book arts artist books installation archive collection kallitype collotype photography printmaking letterpress ghost climate change Geology time pigment Land Art Erdlebenbildkunst panorama ink identity place grid cartography Art Practice

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