Herkunft der Salinität in Tiefenwässern des Grundgebirges – unter besonderer Berücksichtigung der Kristallinwässer des Schwarzwaldes

Deep groundwater in fractured crystalline basement has been reported from deep mines and scientific wells. Highly saline brines have been described from several km depth in the continental basement worldwide. The origin of salinity is unknown and many different possibilities have been presented ( Emmermann et al. 1995, Pauwels et al. 1993, Edmunds &;: Savage 1991, Frape &;: Fritz 1987, Kozlovsky 1984, Banks et al. 1996, Stober 1986, 1995, Kanz 1987, Stober &; Bucher 1999). We compare the compositional evolution of deep waters in the Black Forest basements, SW-Germany, with those of other deep crystalline waters and use the halogen systematics (e. g. Cl/Br ratios) and other parameters of the waters to deduce the origin of their salinity. In teh Black Forest the composition of deep thermal waters results from chemical interaction of surface water with the rock matrix and from mixing of the reacted water with stagnant saline deep water of marine origin.     

Kfz-Pflichtstellplätze außerhalb des Bauplatzes

Kfz-Stellpl?tze in einer Entfernung von 940 m liegen nicht mehr im "Umkreis von zirka 500 m". Auf Besonderheiten eines Bezirkes oder Bezirksteiles (hier: der Wiener Innenstadt) kann in diesem Zusammenhang nicht Bedacht genommen werden.     

Anwendung des Neutralisationspotenzials bei der Bilanzierung von Säure-Base-Reaktionen im Umfeld des Braunkohlebergbaues

Acidic conditions of seepage and groundwater originating from open pit minings in Lusatia are described using the neutralization potential, which is based on the concept of acidity. Acid formation and buffer reactions can be reduced to three elemental reactions: oxidation of pyrit/reduction of sulfate, dissolution of carbonate and gypsum equilibrium. These reactions are combined in a genetic model in order to interpret the origin of mineral and acid contents of different groundwaters influenced by lignite mining. The statistical results of these calculations are summarised in order to calibrate parameters of a prognostic model. The method described here is used to prepare restoration measures.     

Methoden zur Abschätzung der Verschmutzungsempfindlichkeit des Grundwassers

The increasing threat of groundwater contamination by pollutants has led to the development of methods to assess groundwater vulnerability on a regional scale. An assessment of groundwater vulnerability will also be required by the coming EU framework directive on water. The concept of groundwater vulnerability is discussed and available methods are presented. These include hydrogeological complex and setting methods, analogue relations and index methods, point rating and matrix systems, mathematical models and statistical approaches. The methods and their principal characteristics are explained and summarised with emphasis on their regional usability.     

Isotopenphysikalische Beiträge zur Beurteilung des Grundwasserschutzes im Buntsandstein

The complex application of isotope physical measuring methods together with model calculations for groundwater flow and hydrochemistry is helpful to estimate groundwater vulnerability. Thereby Tritium is used as a natural tracer of local groundwater input indicating a possible groundwater vulnerability, and the far-reaching, long-term groundwater migration is derived from Carbon-14 ages of dissolved inorganic carbon. For the case “double-porosity aquifer (Finne Bunter Sandstone, Saxonia-Anhalt)” the derivation of hydrogeological parameters as groundwater recharge, groundwater flow and the water exchange rate of an aquifer is demonstrated. Especially information on the groundwater vulnerability can be obtained without any real groundwater contamination.     

Flächenwidmung "Freiland"; Bordell; Änderung des Verwendungszweckes eines Gebäudes; Nutzungscharakter eines Gebäudes; überwiegende Erhaltung des bisherigen Nutzungscharakters

Bei der Feststellung, ob der "Nutzungscharakter eines Geb?udes" nach einer Verwendungszweck?nderung überwiegend erhalten bleibt, muss die Nutzungsart vor und nach der Verwendungs-zweck?nderung verglichen und überprüft werden, ob trotz der ?nderung der Charakter der Nutzung erhalten bleibt. Beim "Nutzungscharakter eines Geb?udes" ist prim?r auf seine Verwendung abzustellen. Bei der Nutzung eines Geb?udes als Bordellbetrieb anstatt des bisherigen Gasthausbetriebes bleibt der "Nutzungscharakter des Geb?udes" überwiegend erhalten.     

Ein neues Verfahren zur Berechnung des räumlichen passiven Erddrucks vor Trägern

A calculation method for the spatial passive earth pressure acting on girders. This paper presents a calculation method for vertical girders in cohesionsless soils. Measurements on buildings and model experiments are the basis. The Distinct Element Method (DEM) was extended and improved to enable the numerical simulation of load tests. Based on this knowledge, conditions not covered by experiments was simulated by means of the DEM. Accordingly, the test matrix could be extended. With the results of these simulations a new calculation method was derived.     

Missstände bei der Vollziehung des Baurechts. Aktuelle Fälle aus der Volksanwaltschaft 2007

Aufgabe der Volksanwaltschaft ist es, auf Grund von Beschwerden oder von Amts wegen Missst?nde in der Verwaltung des Bundes und – auf der Grundlage landesverfassungsrechtlicher Erm?chtigungen (Bgld, Krnt, N?, O?, Sbg, Stmk, Wien) – der L?nder einschlie?lich des eigenen Wirkungsbereichs der Gemeinden zu prüfen. In diesem Zusammenhang hat die Volksanwaltschaft auch wichtige, praxisrelevante Rechtsfragen des Baurechts zu kl?ren. Die Ergebnisse sollen ein- bis zweimal pro Jahr bundesl?nderweise und in Leitsatzform dokumentiert werden.     

Hydrogeologie des Oberen Muschelkalks im Bereich hoher Keuperüberdeckung – Modell Schwäbisch-Fränkische Waldberge

A numerical groundwater model was developed for the aquifer of the Upper Muschelkalk between the rivers Neckar, Kocher and Murr. The investigation shoudl mainly serve a better understanding of the hydrogeological situation of this aquifer below the thick Keuper sediments of the Schwäbisch-Fränkischen Waldberge. Here we observe a general groundwater discharge in direction of the rivers with an average hydraulic gradient of 1%. The groundwater recharge from precipitation is estimated at 0.001 m ³ /s for the region below the Keuper mountains, which covers an area of 730 km ² , and 1 m ³ /s for the foreland with an area of 670 km ² . Similar conditions are found comparing the mean pore velocities of both areas (0.4 respectively 200 m/year) and the mean residence time (20000 respectively 20 years) of the groundwater. Thus, the aquifer of the Upper Muschelkalk below the Schwäbisch-Fränkischen Waldberge can be characerized as a fractured non karstified aquifer of low conductivity.     

Charakterisierung von Karstgrundwasserleitern durch Simulation der Aquifergenese und des Wärmetransports

This paper is intended to provide an overview of an integrated modelling approach which allows for long-term simulations of aquifer genesis and for short-term simulations of heat transfer in karst aquifers as well. This approach is based upon a conceptual model of karst systems incorporating their dualistic flow pattern, calcite dissolutions kinetics and heat transport processes. The modelling tool which has been developed proves to be a useful device for testing hypotheses on the structure of karst aquifers and for investigating typical scenarios of the development of carbonate aquifers. For this purpose, two examples referring to a dendritical conduit network which is coupled to a fissured system are discussed.     

Das Verhalten des Benzininhaltsstoffes Methyltertiärbutylether (MTBE) in Grundwasser

Monitored natural attenuation can be an effective and reasonable remediation strategy at petroleum release sites. Methyl-tertiary-butyl-ether (MTBE), the most commonly used gasoline osygenate, is added to gasoline to reduce air pollution and to enhance octaine. In North America, MTBE has been used since the 70s. This compound is highly water soluble (approximately 50 g/l), mobile, difficult to biodegrade and has a very strong taste and odour even at concentrations below 100 μg/l. The toxic effects of MTBE on aquatic life and humans have not been assessed in any detail and only sparse data on the potential impact of MTBE on groundwater resources are available. In Europe, this compound is very rarely monitored in the environment. The wide use of MTBE, its physical and chemical properties and its poor biodegradability make this compound a potentially problematic groundwater contaminant. Therefore, MTBE is gasoline spills may compromise the use of natural attenuation as a remediation strategy.     

Missstände bei der Vollziehung des Baurechts. Aktuelle Fälle aus der Volksanwaltschaft 2008/1

Aufgabe der Volksanwaltschaft ist es, auf Grund von Beschwerden oder von Amts wegen Missst?nde in der Verwaltung des Bundes und – auf der Grundlage landesverfassungsrechtlicher Erm?chtigungen (Bgld, Krnt, N?, O?, Sbg, Stmk, Wien) – der L?nder einschlie?lich des eigenen Wirkungsbereichs der Gemeinden zu prüfen. In diesem Zusammenhang hat die Volksanwaltschaft auch wichtige, praxisrelevante Rechtsfragen des Baurechts zu kl?ren. Die Ergebnisse sollen ein- bis zweimal pro Jahr bundesl?nderweise und in Leitsatzform dokumentiert werden.     

Experimentelle Bestimmung des maximalen Säurebildungs- bzw. Pufferungspotentials von sulfidhaltigen Lockergesteinen

A simple titrimetric oxidation test using hydrogen peroxide was developed for the determination of the maximum quantity of acid releasable from tip sands by pyrite oxidation. The acid buffering capacity of the respective sample can be estimated by balancing the maximum amount of acid releasable by weathering (worst case) with the amount calculated theoretically from the total sulphur. The measurement of the pH and the electrical conductivity in the oxidised sample already allows a semi-quantitative assessment of the worst case. These analysis methods, conductable with little laboratorial expenditure and appliable to large sample quantities are used to estimate the maximum possible acid release from aquifers.     

Pumpspeicherbecken im Karstgrundwasserleiter des Weißen Jura der Schwäbischen Alb

Extensive geological and hydrogeological investigations have been undertaken for the planned pumped-storage hydroelectric power plant in “Blautal” (Swabian Alb, Germany) in order to characterise the Jurassic karst aquifer in which the lower reservoir will be constructed. The preferred option for the plant setup is to integrate the lower reservoir into the groundwater without sealing. Therefore, in order to reliably predict the impact of the pumped storage plant operations on the surrounding drinking water wells and groundwater dependent ecosystems, a comprehensive database has been developed to assess the hydraulic conditions of the karst aquifer. A large scale geological site investigation was carried out to characterise the rock mass and extensive hydraulic tests were performed in many boreholes. The results of the hydraulic characterisation were then implemented in a three dimensional flow model. In this paper, the first results of the geological and hydrogeological investigations are presented and discussed.     

Seltenerdelement-, Yttrium-Gehalte und Bleiisotope in Thermal- und Mineralwässern des Schwarzwaldes

In the Black Forest, mineral waters from five wells in crystalline basement (granite and gneisses), their probable source rocks and the experimental leachates were evaluated for rare earth elements (REE), yttrium contents, and lead isotope ratios. The distribution of REE and Y, and the Pb-isotope ratios are powerful tools to identify the most likely type of rock that controls cation contents of the mineral water. Granites and gneisses lead to REE patterns with varying negative europium anomalies in waters; i. e., gneisses have a tendency for positive or only slightly negative europium anomalies in fluids, whereas granites exhibit negative anomalies. The comparison of REE and Y in the leachates and waters shows that these elements are characteristically redistributed during water-rock inter-action between rock-forming and accessory minerals, surface layers and adsorption films. REE and Y are leachable in the aquifer rocks, in which light REE are partially impoverished. REE and Y in samples from surface outcrops show enhanced leachable fractions. In alterated rocks, large fractions of ²⁰⁶ Pb are definitely leached from other solid phases than ²⁰⁷ Pb and ²⁰⁸ Pb.     

Über die Modellierung des Tragfähigkeitsverlusts von Verpreßankern unter Angriff von kalklösender Kohlensäure

On the reduction of the bearing capacity of cement grouted anchors under the attack of aggressive carbonic acid. The presence of lime attacking carbonic acid in soil or ground water leads to a time dependent reduction of the bearing capacity of cement grouted anchors. An extensive experimental program, consisting of long term tests as well as direct shear and pull-out tests with cement bodies and interfaces were carried out to investigate the results of this attack. This article deals with the theoretical modelling of this solving attack and its influence on the bearing capacity of anchors. The time depending corrosion depth and its influence on the shear parameters are integrated in a dilatation stress model describing the anchor capacity. The decrease of the radial restraint of the cement grouted anchor depends mainly on the convection of the corroded material into the soil pore space, which in turn leads to a decrease of the initial density of the surrounding soil.     

Gefährdung des Grundwassers durch Freisetzung organischer Schadstoffe: Methoden zur Berechnung der in-situ-Schadstoffkonzentrationen

The release of pollutants from contamined soils can be due to desorption and dissolution from residual phase blobs or pools. Volatile compounds can diffuse from contaminated soil air into the groundwater. This paper discusses the basic release processes and presents methods for the calculation of the rates of desorption, dissolution and diffusion. These rates are a prerequisite for the determination of the in-situ contaminant concentration in groundwater. The necessary parameters can be estimated from empirical correlations or may be measured directly in laboratory experiments. Column experiments, e. g., yield maximum release rates in the case of slow diffusion limited desorption whereas dissolution of contaminants from blobs of residual phase results in maximum concentration (solubility) in the column effluent.     

Messung der Infiltrationsgeschwindigkeit von Oberflächenwasser mit Hilfe des natürlichen Isotops Radon-222

Owing to its different concentrations in groundwater and river water, the naturally occuring isotope radon-222 can be used as a natural tacer to determine the residence time of freshly infiltrated water and the infiltration velocity. In the study area, predominant correlation was found between the radon activity concentration of groundwater and the lithologic structure of the aquifer. Misinterpretation of low radon activity concentration measured near surface waters due to geological inhomogeneities can result in false assumptions about groundwater flow paths. The infiltration of river water into the adjacent aquifer during a flood wave was also ascertained by measuring radon activity concentration. Further the residence time of infiltrated water was determined at a sampling point installed beneath the river Elbe and infiltration velocity was calculated.