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.

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.

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.

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.

In this thesis, the central interest is to better understand how participatory methods applied during participatory processes in natural resources management can serve as nuclei for social learning. Thereby, the main focus is on learning via interaction in groups. My approach begins with the aim of developing an analytical framework which reflects the main processes that are effective within participatory methods. The framework presents an analytical tool, including proposed methods to monitor and compare the results of participatory approaches with respect to social learning. Building upon this framework, I develop an agent-based model to simulate and explore group dynamics. This model is intended to support a theoretical exploration of whether or not and if so, at what stage, personal views of a problem evolve into a shared understanding of a problem (which can be seen as a key element of social learning), and an assessment of how individual mental models and group properties relate to each other. Results of the model are interpreted to offer suggestions about factors hindering or fostering social learning during the application of participatory methods.

Up to now, politics and societies from all over the world have sought an economy that is built on the idea of continual growth to establish a wealthy future and achieve societal prosperity. At the same time, people have neglected to consider that the resulting environmental pollution is the largest cause of disease and death in the world today. Therefore, it appears sensible to ensure that people’s well-being and nature’s well-being is uncoupled from profit-orientated aims. To break the circle of continual growth and the decreasing well-being of humans and nature, individual sustainability traits that are able to foster a transition to sustainable development need to be explicitly identified. Today’s young people will presumably face an even more severe level of consequences resulting from continual growth, which will reach far into the future, thereby affecting the living environment of future generations even more drastically. Therefore, this dissertation aims to answer the question of how young people possess and profit from their sustainability traits in terms of well-being. This work approaches this question by empirically investigating different interrelations between environmental values, the perception of environments (including the perception of naturalness and the perception of aesthetics), environmental concern and well-being in the context of young people. The empirical section is divided into three parts that investigate the different relationships step by step. These three parts are based on three different quantitative questionnaire surveys of young people in Germany. In the first survey (N = 229; Mage = 13.27 years, SD = 2.37 years), the relation between secondary school students’ human-nature relationship as a sustainability trait and their well-being was investigated. Analyses showed that the sustainability trait of human-nature relationships was significantly related to young people’s age-dependent well-being through nature perception in terms of naturalness and aesthetics as well as through individual nature connection. Young people were shown to profit from nature as resource for their own well-being. A positive human-nature relationship could be described as an important requirement for people to achieve sustainable development. In a second inquiry, university students (N = 237; Mage = 22.12 years, SD = 3.09 years) with a focus on the interrelations of sustainability traits that showed relations to people’s well-being in past research were surveyed. The results describe the interrelations between the specified sustainability traits of environmental values, a newly developed scale that theoretically and empirically validated affective nature connection, cognitive nature connection, and environmental concern. The findings indicate that the chosen sustainability traits mutually contribute to each other’s impact and do not preclude each other. Future research based on the results of the two described studies will likely show that sustainability traits are desirable characteristics and useful attributes that are available all over the world, no matter what a person’s age. As a final step, secondary school students’ environmental concern and well-being were quantitatively surveyed (N = 2173; Mage = 14.56 years, SD = 1.45 years) to analyze how environmental concern as a sustainability trait predicts young people’s well-being. The children’s and adolescents’ sustainability trait of environmental concern was able to predict young people’s well-being, with a clear dependence on age. The obtained outcomes supporting the aim to possess nature as a resource of well-being need to be considered in terms of young people’s age. Youth seem to experience sensitive periods of time in which the youth’s sustainability traits evidently act differently than in other stages of life. Hence it is important to point out that especially young people need age-appropriate treatment in terms of education for sustainable development to successfully foster young people’s sustainability traits. The main goal of this dissertation was to explore and identify in-depth insights into young people’s sustainability traits and their interrelations as well as the connections to young people’s well-being. As such interrelations between sustainability traits and well-being meet the aims of sustainable development as well as political and societal aims for a healthy future life environment for everyone which is expected of continual (economic) growth up to the present time, age-dependent education for sustainable development could address the need for young people to become progressive decision makers who create future-proof solutions for themselves and others, considering the constitution of a worthy life for present and future generations.

Bei der Publikation handelt es sich um den Abschlussbericht einer erstmals durchgeführten Befragung der Absolventen der Fakultät Bauingenieurwesen der TU Dresden zum beruflichen Verbleib und zur retrospektiven Bewertung der Studienqualität. Der vorliegende Abschlussbericht gliedert sich zunächst in eine Kurzzusammenfassung der wichtigsten Ergebnisse, dann in einen Abschnitt zur Anlage und Durchführung der Studie und in Abschnitte zu den einzelnen Themengebieten der Befragung. Im einzelnen wurden in Zusammenarbeit mit der Hochschulleitung der TU Dresden als Ziele und Themen der Absolventenbefragungen formuliert: An erster Stelle stand die Informationsgewinnung zum Verbleib der Absolventen, ihrer Berufsfelder, Einkommen, Arbeitszufriedenheit und Arbeitsmarktchancen. Die Informationsgewinnung zur retrospektiven Bewertung der Qualität der Lehre und des Studiums durch Absolventen stand an zweiter Stelle. So sollen durch die Fakultäten auch Anregungen und Verbesserungsvorschläge zur Reform von Studienprogrammen abgeleitet werden können und Vergleichsmöglichkeiten mit der Bewertung der Lehre und des Studiums durch Studenten gewonnen werden. Weitere Ziele waren Vorbereitungen für kontinuierliche Absolventenbefragungen an allen Fakultäten der TU Dresden sowie Fragebogen-Adaptionen für die Fakultäten. Schließlich wurde als langfristiges Ziel die Entwicklung eines fundierten Befragungsdesigns für Längsschnittstudien (Wiederholung der Befragungen nach mehreren Jahren mit denselben und neuen Absolventen) flächendeckend für alle Fakultäten der TU Dresden genannt. Zusätzlich zu den einzelnen Themengebieten der Befragung erfolgte eine Analyse der Bestimmungsgründe beruflichen Erfolgs. Gerade letztere Analyse führte auch zu einigen unerwarteten Ergebnissen. Gängige (hochschulpolitische) Thesen, welche Absolventen besonders erfolgreich seien, konnten nicht bestätigt werden. Andere Eigenschaften erwiesen sich als wesentlich wichtiger. Weitere Informationen zu den Dresdner Absolventenstudien finden Sie auch im Internet unter "www.tu-dresden.de/phfis/lenz/fo/Absolventenstudie.html"

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