02 Fakultät Bau- und Umweltingenieurwissenschaften
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/3
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Item Open Access Quantitative evaluation of clogging phenomena in river beds(1982) Geldner, Peter; Kobus, HelmutClogging phenomena in rivers are of extremely complex nature, and a development of a clogging layer depends on a large variety of influences. In this paper a quantitative approach for the evaluation of a defined hydrodynamic clogging parameter is presented. This approach is based on the inverse use of type curves representing characteristics of the interaction between surface water bodies and the aquifer. The method is applied to field data of discharge measured in seepage ditches at levee protected sites. Since conventional approaches are limited to the assumption of quasi-steady-state flow, a stochastic method for the evaluation of time-variable hydrographs is also outlined.Item Open Access Relating hydraulics and ecological processes(1991) Hjorth, Peder; Kobus, Helmut; Nachtnebel, Hans Peter; Nottage, Albert; Robarts, RichardAny major modification of the hydraulic system results with some retardation in a response of the ecosystem trying to adapt to the new conditions. It is difficult to imagine situations where hydraulics and ecosystems are not related. Thus, harmonizing hydraulics with ecology means to identify alternative hydraulic measures which yield simultaneously economic benefits and improvement, preservation or at least a best fit of the environmental situation. Often, these objectives are subjected to an inherent conflict and therefore harmonizing is dependent on the preference structure of the modern society, which is inclined to sustainable development. The objective of this chapter is to develop a framework (methodology) which might assist in relating hydraulics and ecology with respect to specific goals under site and problem dependent constraints.Item Open Access The sub-systems. 4 : Groundwater(1991) Herrmann, Reimer; Hubert, P.; Kobus, HelmutGroundwater constitutes the most important freshwater resource of the earth, it is two orders of magnitude larger than the total water volumes of rivers and lakes. It is a renewable resource, characterized by stability of its chemical composition and stability of temperature. Percolation of water through the subsurface has a good purification effect due to the combined action of filtration, sorption, chemical reactions and microbiological processes. Groundwater is utmost important as drinking water resource, since it is less prone to pollution than surface waters due to the protection effects of the covering layers. However, industrial and agricultural activities have led to groundwater pollution problems which are sometimes irreversible and in any case very difficult and expensive to recover. This endangers the long-term use for drinking water supply, and any efforts for sustainable development have to consider the vulnerability of groundwater resources to pollution, which shows great regional diversity, by suitable groundwater protection efforts.Item Open Access Temperaturanomalien in Porengrundwasserleitern zufolge Warm- oder Kaltwassereinleitungen(1983) Kobus, Helmut; Söll, Thomas; Mehlhorn, HansEs werden eindimensionale Berechnungsverfahren vorgestellt, die dem Planer eine Orientierungshilfe zur Abschätzung der Reichweite von Temperaturanomalien im Grundwasser geben. Zeitliche Variationen der Einleitungstemperaturen und der Infiltrationsrate werden diskutiert. Die Entwicklung der Temperaturanomalie bis zum Erreichen eines quasistationären Endzustands wird aufgezeigt und anhand von Zahlenbeispielen erläutert.Item Open Access Kapitel 8, Grundwasserschutz : Sanierung kontaminierter Standorte(1987) Grimm-Strele, Jost; Kobus, Helmut; Geldner, PeterIn der Bundesrepublik befinden sich nach Schätzungen ca. 30.000 kontaminierte Standorte, von denen etwa ein Fünftel in nächster Zeit saniert werden muß. Die Aufgabe, solch einen kontaminierten Standort zu sanieren, besteht darin, die Gefährdungen, die von dem Standort ausgehen, zu erkennen, zu bewerten und zu beseitigen bzw. weitgehend einzuschränken. Das Ausmaß der Gefährdung bestimmt dabei die Intensität der Erkundung und den Umfang der Sanierungsmaßnahmen. In Abhängigkeit von den Zielen der Messung der Grundwasserbeschaffenheit müssen verschiedene Vorgehensweisen oder Maßstrategien verfolgt werden. Dazu müssen vor allem Festlegungen über die Meßverfahren, die Meßpunkte, die Meßhäufigkeit und die Meßparameter getroffen werden. Das häufigste Meßverfahren, das bei den folgenden Ausführungen im Vordergrund steht, ist die Entnahme von Wasserproben aus der gesättigten Zone an geeigneten Meßstellen wie Beobachtungsrohren, Förderbrunnen, Quellen oder ähnlichem und die anschließende Analyse im chemischen Labor.Item Open Access Field, theoretical and numerical studies of dispersion : Berichtszeitraum: August bis Oktober 1988(1988) Moltyaner, Gregory; Kobus, Helmut; Teutsch, Georg; Kaleris, Vassilios; Schäfer, GerhardA cooperative effort between the University of Stuttgart has developed an expertise in computational aspects of transport in geologic media and in the performance of large-scale laboratory tracer experiments and Chalk River Nuclear Laboratories, Ontario that has broad experience in the performance, analysis and interpretation of field tracer tests on a variety of scales. The proposed investigations respond to the current needs on resolving major scientific hypotheses required to advance the understanding and predictive modelling of contaminant transport in natural geologic environments. This concerns the migration of chemically inert tracers in geologic media, physical and numerical modelling of transport and theoretical aspects of migration.