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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Die Lebenssituation älterer Menschen und ihr Verhalten als Besucher von Seniorenkreisen / Eine sozialgeographische Untersuchung in Braunschweig und Peine

Zohner, Udo 30 October 2000 (has links)
No description available.
62

Räumliche Handlungskonzepte: Ein Blick auf Probleme ihrer Erarbeitung und Umsetzung

Altholz, Vitali 22 September 2011 (has links) (PDF)
Die Dissertation untersucht auf der Basis der Inhaltsanalyse von 429 deutschsprachigen Konzepten der Raumplanung sowie mit Hilfe von 17 ExpertInneninterviews verschiedene Problemzustände der Planung und Umsetzung räumlicher Entwicklungsmaßnahmen sowie den Umgang mit diesen Problemzuständen seitens der raumplanerischen Praxis und der Raumpolitik in Deutschland, Österreich und der Schweiz. Dabei wurde – neben allgemeinen Informationen über inhaltliche Schwerpunkte und Ausrichtungen der untersuchten Konzepte, ihre Planungszeiträume und Autoren sowie Entscheidungsverfahren und -methoden – ein differenzierter Katalog unterschiedlicher Problemzustände und kritischer Faktoren erstellt, welcher bei der konzeptionellen Ausrichtung zukünftiger Konzepte als Orientierungshilfe dienen kann. Der Autor diskutiert die heutige Rolle räumlicher Handlungskonzepte und weist eindringlich auf die Problematik der Verdrängung kritischer Zustände im Zusammenhang der Erarbeitung und Umsetzung räumlicher Handlungskonzepte hin.
63

Räumliche Handlungskonzepte: Ein Blick auf Probleme ihrer Erarbeitung und Umsetzung

Altholz, Vitali 24 June 2011 (has links)
Die Dissertation untersucht auf der Basis der Inhaltsanalyse von 429 deutschsprachigen Konzepten der Raumplanung sowie mit Hilfe von 17 ExpertInneninterviews verschiedene Problemzustände der Planung und Umsetzung räumlicher Entwicklungsmaßnahmen sowie den Umgang mit diesen Problemzuständen seitens der raumplanerischen Praxis und der Raumpolitik in Deutschland, Österreich und der Schweiz. Dabei wurde – neben allgemeinen Informationen über inhaltliche Schwerpunkte und Ausrichtungen der untersuchten Konzepte, ihre Planungszeiträume und Autoren sowie Entscheidungsverfahren und -methoden – ein differenzierter Katalog unterschiedlicher Problemzustände und kritischer Faktoren erstellt, welcher bei der konzeptionellen Ausrichtung zukünftiger Konzepte als Orientierungshilfe dienen kann. Der Autor diskutiert die heutige Rolle räumlicher Handlungskonzepte und weist eindringlich auf die Problematik der Verdrängung kritischer Zustände im Zusammenhang der Erarbeitung und Umsetzung räumlicher Handlungskonzepte hin.
64

Modellierung, Analyse und Bewertung des chemischen Gewässerzustandes in Flussgebieten

Heß, Oliver 13 June 2005 (has links)
Modellierung, Analyse und Bewertung des chemischen Gewässerzustandes in Flussgebieten Der Schwerpunkt der chemischen Belastungen von Oberflächengewässern durch Abwasseremissionen verlagert sich in jüngerer Zeit, durch die Ertüchtigung der Abwasserreinigungsanlagen, von biologisch leicht abbaubaren organischen Substanzen hin zu Mikroverunreinigungen. Die Expositionsanalyse von Gewässersystemen gegen xenobiotische Substanzen mit dem Ziel einer Steuerung der Belastungen rückt immer mehr in den Vordergrund des Interesses (EG 2000, EG 2001). Am Beispiel des nordrhein-westfälischen Rheineinzugsgebiets wird in der vorliegenden Arbeit eine Analyse und Bewertung des chemischen Gewässerzustandes durch georeferenzierte Modellierung von Flussgebieten durchgeführt. Eingesetzt wird das Modellsystem GREAT-ER (Georeferenced Regional Exposure Assessment Tool for European Rivers). Der methodische Teil der Arbeit beschreibt die Kalibrierung des Modellsystems für das Einzugsgebiet des Rheins in Nordrhein-Westfalen. Weiter werden die für die Modellierung notwendigen Eingangsparameter verschiedener beispielhafter Substanzen aus verschiedenen Quellen hergeleitet. In den Anwendungsstudien werden Simulationsergebnisse für die Stoffe Bor, EDTA, HHCB, und Diclofenac sowie Diuron und Ammoniumstickstoff dargestellt und mit Messwerten der Gewässerkonzentrationen verglichen. Die Emissionsmengen für Bor und EDTA aus dem Gebrauch im Haushalt sind gut quantifizierbar. Beide Substanzen verhalten sich in den Gewässern konservativ und konnten deshalb für die Kalibrierung des Modellsystems genutzt werden. HHCB und Diclofenac sind Substanzen, die typischerweise über Haushaltsabwässer in die Gewässer gelangen, aus diesen jedoch gut eliminiert werden. Das Pestizid Diuron gelangt mit dem Oberflächenabfluss von versiegelten Flächen in das Abwasser und die Gewässer. Die Elimination aus den Gewässern ist gering. In der Arbeit wird eine Quantifizierung der Emissionsmengen auf Basis der versiegelten Flächen durchgeführt und damit eine räumliche Zuordnung der Eintragsmengen erreicht. Mit Ammoniumstickstoff wird schließlich die Gewässerexposition einer Substanz berechnet, die auch über diffuse Quellen in die Gewässer gelangt. Grundannahme ist hier, dass die Frachten aus Punktquellen die diffusen Einträge überlagern. In Abhängigkeit von der jeweiligen Substanz und Lage der Messstellen zeigen die Ergebnisse sowohl gute Übereinstimmung als auch stellenweise große Abweichungen zu den gemessenen Substanzkonzentrationen in den Gewässern. Für die auftretenden Abweichungen ergeben sich Erklärungsansätze, aber auch weiterer Untersuchungsbedarf wird deutlich. Die Ergebnisse der Arbeit belegen, dass das mit GREAT-ER entwickelte Werkzeug zur georeferenzierten Modellierung von Substanzkonzentrationen in Gewässern auf dem Gebiet der zeitlichen und räumlichen Analyse von realen Messwerten und im Rahmen eines Immissions- und Belastungsmanagements einsetzbar ist. Es können aus den Umgebungsparametern begründete Hypothesen zu lokalen Substanzkonzentrationen in Gewässern entwickelt werden, deren Informationsgehalt gegenüber Messung und generischer Modellierung höher ist.
65

Ermittlung von (Miss-)Erfolgsfaktoren für die Umsetzung der EG-Wasserrahmenrichtlinie in Agrarintensivregionen / Determination of Failure and Success Factors for the implementation of the EU Water Framework Directive in Regions with Intensive Agriculture

Kastens, Britta 16 April 2008 (has links)
The cumulative dissertation at hand addresses the question of how promising the successful implementation of the WFD is. Since research on implementation deficits has so far mainly considered national and sub-national levels, regional and local scales are taken centre stage within the dissertation. The Hase river catchment, which is located in one of Germany s most intensive livestock areas, serves as an example. The thesis shows that the procedural character of the WFD and regulative uncertainties give way to interpretation and action leeway, which will be pivotal to judgement on implementation success at lower levels. Moreover, the consistent operationalisation of nitrate limits in particular has led to major difficulties during implementation in Germany from which restraints can be expected for the preparation of river basin management plans and the program of measures. As to the regional level, implementation restraints also upraise due to socio-economic dependencies from agriculture and a high identification of the regional population with this economic sector have placed agriculture in a powerful position. In conclusion, one can state that various implementation restraints occur and the cause of these can be found at all scales European, sub-national and regional. The results of this dissertation concerning the multi-level system reveal that the relationship and interaction of the various scales will be given increased attention during the implementation process of European environmental policy. Besides the national and sub-national scale, the regional and local levels will be of equal importance. The question of suitable scales for implementation decisions and measures also offers pivotal approaches to undertake future research. Further research needs occur with new regional studies at national and international scales, with regard to the future of water protection in the course of the reform of German federalism and the current debate on climate change.
66

Spatial Aspects of Chemical Exposure Assessment: A Tool for River Networks

Wagner, Jan-Oliver 31 October 2001 (has links)
Spatial Aspects of Chemical Exposure Assessment: A Tool for River Networks. Chemical exposure assessment has gained increasing attention in recent years. Its methodologies have enabled scientists and policy-makers to understand exposure paths and to identify environmental compartments of concern. Mathematical models are used for the prediction of a chemical's concentration in a certain compartment and in some cases also for predicting the duration or time of highest load. With the Geo-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) spatial aspects of regional exposure assessment are addressed for the "down-the-drain" path of consumer chemicals such as detergents. On the basis of a carefully developed simulation model (Boeije, 1999), this thesis describes the concept and realization of the developed software tool GREAT-ER. With data composition and processing on the one hand and application and analysis on the other hand, two crucial aspects in spatial exposure assessment are identified and discussed. Geo-referenced real-world data are not readily available in a usable form. An intermediate format is defined to separate the tasks of an initial preparation of raw data from the final aggregation leading to a directly usable data set. It is shown that the latter step can be fully automated and thus efficiently supports an iterative procedure of data quality improvement. The application of GREAT-ER to the substances LAS (readily degradable) and boron (inert) in four Yorkshire catchments demonstrates the ability to predict mean final effluent and in-stream concentrations with an average error of less than a factor of 2. Furthermore, regional summaries and risk characterization add useful information to judging a regional response to the (potential) release of a substance. In conclusion, the development and application of GREAT-ER has proven that geo-referenced exposure assessment is possible with regard to both quality and practicability. Future activities should focus on gaining further experiences in performing simulations, improving the tool itself and extending its abilities. Finally the integration of further models should be evaluated.
67

Dynamics and sustainable use of species-rich moist forests: A process-based modelling approach

Rüger, Nadja 24 January 2007 (has links)
Sustainable use of species-rich moist forests is hampered by an insufficient understanding of their dynamics and long-term response to different wood harvesting strategies. This thesis contributes to a better understanding of natural forest dynamics, explores the productivity of native forests subjected to different management strategies, and quantifies the ecological impacts of these strategies. The thesis focuses on two study regions: tropical montane cloud forest (TMCF) in central Veracruz, Mexico, and Valdivian temperate rain forest (VTRF) in northern Chiloé Island, Chile. The process-based forest growth model FORMIND is applied to study natural forest succession, to assess long-term ecological implications of fuelwood extraction on TMCF, to explore the potential of secondary TMCF for provision of ecosystem services and fuelwood, and to compare potential harvesting strategies for VTRF regarding forest productivity and ecological consequences.Simulation results show that both forest types have a high potential for wood production. As wood extraction increases, the forest structure becomes simplified because large old trees disappear from the forest. The species composition shifts to tree species that are favoured by the respective harvesting strategy. The overall ecological impact increases linearly with the amount of extracted wood. Simulation results allow to define management strategies that balance conservation and production objectives, promote the regeneration of desired tree species, or minimise shifts in the species composition of the forest. Process-based forest models enhance our understanding of the dynamics of species-rich moist forests and are indispensable tools to assess long-term implications of anthropogenic disturbances on forest ecosystems. Thereby they contribute to the conservation and sustainable use of native forests outside protected areas.
68

Modelling and evaluating the aquatic fate of detergents

Schulze, Carsten 08 May 2001 (has links)
Modelling and evaluating the aquatic fate of detergents - Abstract Within this thesis an environmental assessment and evaluation method for analysing aquatic ecotoxicological impacts of household laundry is developed. The methodology allows comparative assessments of different product alternatives, washing habits, and wastewater treatment techniques in order to identify their relevance with respect to waterborne discharges. Elements from both analytical tools Life Cycle Assessment (LCA) and Environmental Risk Assessment of chemicals (ERA) are combined in this methodology. The core consists of the Geography-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER), which calculates concentrations of `down-the-drain' chemicals in surface waters due to point releases. In order to simulate the aquatic fate of detergents, a new GREAT-ER emission model is developed, called GREAT-ER product mode, which calculates calculates concentration increases of detergent ingredients in surface waters based on product formulations and assumptions concerning washing habits. Two evaluation methods, the Critical Length (CL) and the Product Risk Ratio (PRRx), are defined for evaluating the results. CL is the sum of mean concentration increases, divided by substance-specific no effect concentrations (NECs), over all river stretches and all ingredients weighted by the lengths of the stretches. PRRx is the (percentual) number of river stretches in a region, in which the x-percentiles of the predicted concentration increases of at least one ingredient exceed a substance-specific NEC. The emission model requires input data that can be derived from the functional unit of an LCA, which allows an assessment of other impact categories by using any existing LCA method. The methodology is applied to a case study which is based on scenarios given in the comprehensive product assessment `Washing and washing agents' (`Produktlinienanalyse', PLA). In order to apply the GREAT-ER product mode, the Rur river basin in Western North-Rhine Westphalia is chosen as study area. The catchment integration includes the development of a simple hydrological model that combines a nonlinear regression analysis with a local refinement procedure. The quality of the integration of the Rur catchment data is analysed by a comparison of monitoring data and predicted concentrations of detergent and cleaning agent ingredients using actual consumption data of the two years 1993 and 2000. The product mode results show that use habits have a larger influence on the results than product formulations. However, the largest influence is caused by varying wastewater treatment techniques. Boron and the surfactants are the most relevant detergent ingredients. Furthermore, using different detergents for white and coloured laundry lowers the predicted emissions significantly. Based on this methodology, sustainable development indicators (SDIs) for describing the aquatic aspects of household laundry are defined. CL is proposed as pressure indicator and PRRx as state indicator for describing aquatic aspects of the sustainability of household laundry in a region. Different regions can be compared by normalising the CL by the region's population and expressing the PRRx as a percentage of stretches in a region. Annually evaluating regional CLs and PRRxs allows the assessment whether a region is moving towards a more sustainable state. Concluding, the new method analyses and evaluates the environmental fate of detergents discharged after use via the wastewater pathway. It provides information not obtainable by other existing methods, which has been made possible due to the focussing on a specific application, for which the method is developed. Its application in the context of sustainable development offers a means to evaluate environmental implications of this important human activity.
69

Sustainable grazing management in semi-arid rangelands. An ecological-economic modelling approach

Müller, Birgit 28 March 2006 (has links)
The loss of utilisable rangeland in semi-arid areas results in huge economic and social costs worldwide. Only adaptive management strategies are able to cope with these systems, which are largely driven by unpredictable and stochastic rainfall. Additionally they are characterized by strong feedback mechanisms between economic and ecological factors. This study aims to contribute to the identification of basic principles for sustainable grazing management. The approach emphasizes learning from existing management systems through the use of ecological-economic modelling. Two apparently successful management systems in Namibia are used as a starting point for a broader analysis: the Gamis Karakul sheep farm and the land use system of the semi-nomadic Ova-Himba. Although the economic systems differ strongly, their management seems to have similarities: the importance of pasture resting and of adapting livestock numbers to available forage. This PhD thesis contributes substantial insights about the relevance and functioning of pasture resting for sustainable grazing management in semi-arid regions. Assessment of the two case studies leads to the hypothesis that resting in the rainy season, particularly during wet years, is fundamental for ensuring pasture productivity under low regeneration potential of the vegetation. The thesis highlights that resting during wet years acts as a risk reducing strategy. Additionally, the study reveals that access to economic risk management strategies, such as rain-index-insurance, may change farmer´s behaviour towards less conservative strategies. The used approach - learning from existing apparently successful grazing strategies by ecological-economic modelling - offers a powerful tool for tackling new questions related to global change. The scope and the limits for generalizing the key factors discovered for sustainable grazing management can be easily detected under changing ecological, climatic and economic conditions.
70

Integrated and Ecological Planning of Sustainable Tourism Development in A rural Area in Indonesia / The Case Study of Tana Toraja, Sulawesi. / Integrierte und ökologische Planung der nachhaltigen Tourismus-Entwicklung im ruralen Gebiet von Indonesia / die Fallstudie von Tana Toraja, Sulawesi

Avenzora, Ricky 28 April 2003 (has links)
No description available.

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