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Found 29 results.

Sustainable Water Resources Management in the Yanqi Basin, Sinkiang, China

Irrigation in the Yanqi Basin, Sinkiang, China has led to water table rise and soil salination. A model is used to assess management options. These include more irrigation with groundwater, water saving irrigation techniques and others. The model relies on input data from remote sensing.The Yanqi Basin is located in the north-western Chinese province of Xinjiang.This agriculturally highly productive region is heavily irrigated with water drawn from the Kaidu River. The Kaidu River itself is mainly fed by snow and glacier melt from the Tian Mountain surrounding the basin. A very poor drainage system and an overexploitation of surface water have lead to a series of environmental problems: 1. Seepage water under irrigated fields has raised the groundwater table during the last years, causing strongly increased groundwater evaporation. The salt dissolved in the groundwater accumulates at the soil surface as the groundwater evaporates. This soil salinization leads to degradation of vegetation as well as to a loss of arable farmland. 2. The runoff from the Bostan Lake to the downstream Corridor is limited since large amount of water is used for irrigation in the Yanqi Basin. Nowadays, the runoff is maintained by pumping water from the lake to the river. The environmental and ecological system is facing a serious threat.In order to improve the situation in the Yanqi Basin, a jointly funded cooperation has been set up by the Institute of Environmental Engineering, Swiss Federal Institute of Technology (ETH) , China Institute of Geological and Environmental Monitoring (CIGEM) and Xinjiang Agricultural University. The situation could in principle be improved by using groundwater for irrigation, thus lowering the groundwater table and saving unproductive evaporation. However, this is associated with higher cost as groundwater has to be pumped. The major decision variable to steer the system into a desirable state is thus the ratio of irrigation water pumped from the aquifer and irrigation water drawn from the river. The basis to evaluate the ideal ratio between river and groundwater - applied to irrigation - will be a groundwater model combined with models describing the processes of the unsaturated zone. The project will focus on the following aspects of research: (...)

Forest functions arrangement with the CBD's Ecosystem Approach - A study on the Bengawan Solo River Basin, Java, Indonesia

The natural capital of forests consists to a great extend of the forests environmental functions for human well-being, which not only include goods and services (source and sink functions) but also include life-support functions that reflect ecosystem performance (ecosystem functioning). Shifting the management approach from a traditional one to one that is more aware of the ecosystem complexity, the idea of 'ecosystem functioning is appearing to tackle gradual declines of ecosystem functions. Within CBDs framework, the Ecosystem Approach has been introduced on account of the necessity for open decision making with strong links between all stakeholders and the latest scientific knowledge due to uncertainty and unpredictability in nature. The Ecosystem Approach is still in need of further elaboration, even though as a concept Ecosystem Approach has been widely accepted. To aim forest enhancement, this approach has been regarded as the most feasible concept for the study area, the Bengawan Solo River Basin - Java, Indonesia. Therefore the principles and operational guidelines will be used to analyse and evaluate the current forest management in those areas of the Bengawan Solo River Basin, in which ecosystem function is the basis for forest development area. This research focuses on ecological functions of forests at various levels of ecosystem management planning, from the forestry sectors point of view.

First-principles kinetic modeling for solar hydrogen production

The development of sustainable and efficient energy conversion processes at interfaces is at the center of the rapidly growing field of basic energy science. How successful this challenge can be addressed will ultimately depend on the acquired degree of molecular-level understanding. In this respect, the severe knowledge gap in electro- or photocatalytic conversions compared to corresponding thermal processes in heterogeneous catalysis is staggering. This discrepancy is most blatant in the present status of predictive-quality, viz. first-principles based modelling in the two fields, which largely owes to multifactorial methodological issues connected with the treatment of the electrochemical environment and the description of the surface redox chemistry driven by the photo-excited charges or external potentials.Successfully tackling these complexities will advance modelling methodology in (photo)electrocatalysis to a similar level as already established in heterogeneous catalysis, with an impact that likely even supersedes the one seen there in the last decade. A corresponding method development is the core objective of the present proposal, with particular emphasis on numerically efficient approaches that will ultimately allow to reach comprehensive microkinetic formulations. Synergistically combining the methodological expertise of the two participating groups we specifically aim to implement and advance implicit and mixed implicit/explicit solvation models, as well as QM/MM approaches to describe energy-related processes at solid-liquid interfaces. With the clear objective to develop general-purpose methodology we will illustrate their use with applications to hydrogen generation through water splitting. Disentangling the electro- resp. photocatalytic effect with respect to the corresponding dark reaction, this concerns both the hydrogen evolution reaction at metal electrodes like Pt and direct water splitting at oxide photocatalysts like TiO2. Through this we expect to arrive at a detailed mechanistic understanding that will culminate in the formulation of comprehensive microkinetic models of the light- or potential-driven redox process. Evaluating these models with kinetic Monte Carlo simulations will unambiguously identify the rate-determining and overpotential-creating steps and therewith provide the basis for a rational optimization of the overall process. As such our study will provide a key example of how systematic method development in computational approaches to basic energy sciences leads to breakthrough progress and serves both fundamental understanding and cutting-edge application.

International Collaboration in Chemistry: First Principles Multi-Lattice Kinetic Monte Carlo Simulations of NOx Storage Reduction Catalysts

The broad objective of the research is to gain a fundamental understanding of the surface reaction chemistry of exhaust catalysts operating under cycling conditions. Using an integrated theoretical approach we specifically target NOx abatement, with particular emphasis on the appearance and destruction of surface oxide phases as the reactor conditions cycle from oxidative to reductive during the operation of the NOx Storage Reduction (NSR) catalyst system. Methodologically this requires material-specific, quantitative and explicitly time-dependent simulation tools that can follow the evolution of the system over the macroscopic time-scales of NSR cycles, while simultaneously accounting for the atomic-scale site heterogeneity and spatial distributions at the evolving surface. To meet these challenging demands we will develop a novel multi-scale methodology relying on a multi-lattice first-principles kinetic Monte Carlo (kMC) approach. As representative example the simulations will be carried out on a PdO(101)/Pd(100) surface oxide model, but care will be taken to ensure a generalization of the multi-lattice first-principles kMC approach to other systems in which phase transformations may occur and result in a change in the surface lattice structure depending upon environmental variables.

Modelling basis and kinetics of nanoparticle interaction with membranes, uptake into cells, and sub-cellular and inter-compartmental transport (NANOTRANSKINETICS)

Objective: The prediction of biological (and in particular toxicological) impacts has, as its basic pre-requisite, the correct prediction of the sites of action and localization of the nano-particle in living organisms. We have identified the need for a paradigm shift in modelling these properties for nano-scale objects. The interactions between bare particles and organisms (cells, biological barriers) is radically different in the presence of proteins and lipids derived from the biological environment (the protein corona). The bare particle characteristic is therefore insufficient to describe the system. Similarly, nano-particles are trafficked and translocated between sites by active biological processes where traditional equilibrium principles for small molecules no longer apply. Nano-TransKinetics is firmly based on advanced high quality experimental data on the distribution of nano-particles in cells, across barriers, and (more limited) in vivo. We frame phenomenological models in a modular manner by abstracting the essential relevant principles of particle-protein (and matrix) interactions, cellular and barrier transport mechanisms of nano-particles, fitting them to experimental data. More detailed models allow for explicit checking of mechanisms and movements of individual particles into cells and across barriers. Enormous amounts of experimental data are now available to validate the models. A predictive capacity requires only simple input data on particle, corona and similar characteristics. The basis of these claims has been checked in preliminary studies, and a limited number of interactions, particles fluxes (and control parameters) between prescribed sites are sufficient to specify the system at each level of description. Resources (reaching far beyond the program itself) have been mobilised in experimental work in the Partners laboratories, and EU and US collaborations. The output will be predictive tools for use in nano-safety research and regulation and beyond.

Trees outside forest: Assessment

Tree resources outside the forest (TOF) serve a number of ecological and socio-economic functions, similar in principle, but different in extent to the functions of forest. This resource is not yet fully recognized in natural resources assessments, particularly on a regional level. Many people in particular in the Tropics depend directly on this resource. For TOF sustainability, politics and management options must be developed and implemented. It means that good information about the assessment of this resource must be available. In this project, options of TOF assessment and mapping on a regional basis will be developed based in the results of earlier studies of the TROF project (EU- INCO DC Program. Contract No ERBIC18 CT98 0323) and others research projects experiences in Latin America. Objectives: To develop an approach to the TOF assessment and mapping on a regional basis.

DFG Priority Program (Schwerpunktprogramm) SPP-1362 Porous metal-organic frameworks

The priority program concentrates on the synthesis, the physical properties and the specific integration of functionality into Metal-Organic Frameworks (MOFs), a new class of porous materials surpassing significantly the adsorption capacity of established materials such as activated carbons and zeolites. They are characterized by a modular construction principle allowing for a rational design of custom made pore systems. Using suitable building blocks, the integration of specific interactions for molecules inside the framework shall be realized for the storage, sensing, transformation, or separation of molecular species inside MOFs. In this way, new materials for energy storage (for example hydrogen or methane) will be constructed. For sensor materials, a change of physical properties should be used for the detection of molecules. For the chemical transformation, materials are important, having specific active catalytic sites in the framework or the pores. In all cases, the focus is to achieve a basic understanding of the interactions of the framework and the adsorbed or reacting molecules. In this context, the experimental determination of the preferred adsorption sites and the dynamics of molecules inside the pore system are crucial. For this purpose, also modeling using modern theoretic methods is needed. In order to enhance the interdisciplinary exchange between chemists, materials scientists, physicists and engineers, generally only such projects will be funded, providing a synergistic cooperation of two or three PIs with different expertise in the following areas of competence: - Synthesis, structure, and reactivity of MOFs - Physical characterization of molecular interactions and dynamics - Theoretic description, simulation, and modeling - Systems and functions. In the program, the modular construction principles of MOFs are used in a rational way for the design of porous frameworks, with functions defined by the constituting building blocks. For the analysis of adsorption, diffusion, and the reaction of guests inside MOFs, structural changes of the molecules and dynamic processes in the frameworks are monitored. Energetic states of molecules inside MOFs and their dynamics are simulated using theoretic quantum chemical calculations and MD-methods for the interpretation of analytic methods and the prediction of functions. An important issue is the application and development of spectroscopic and diffraction methods for the in situ analysis. In this way, formation mechanisms of MOFs, molecular binding sites and catalytic mechanisms in the frameworks are illuminated. By testing the functionality of MOFs, the priority program evaluates the potential of porous Metal-Organic Frameworks in the areas of storage, recognition, separation, or catalytic transformation of molecules.

Will a warmer climate decouple soil respiration (Rs) from net primary production (NPP) in temperate forests?

Atmospheric CO2 enrichment and climatic warming as well as N deposition affect input and output of carbon and nitrogen in soils. This experiment will assess quasi steady state signals of these fluxes and pools by using experiments by nature , i.e. established gradients of temperature and N input, the major drivers of NPP and the soil C balance. We will test the hypothesis that soil respiration (R) is driven by net primary production rather than temperature (T) per se. We will further test the hypothesis that enhanced nitrogen input (here naturally simulated by stands composed of nitrogen-fixing trees) will facilitate greater carbon sequestration. By selecting topography-driven IPCC T-gradients across identical bedrock chemistry and macroclimate and high vs. low N input (Alnus vs. control) we will thus complement data obtained by other projects which employ shorter-term manipulative tests. The work will be conducted in the Swiss midlands and the Central Alps, in part using existing infrastructure at Furka pass (ALPFOR). Our project accounts for the growing international concern about oversimplistic projections derived from idealized (first principle based) laboratory type response functions to large-scale projections (Körner et al. 2007). Our project leans on theory which had been developed earlier by Raich and Nadelhoffer (1989). However, since the majority of experimental approaches adopt manipulative experiments (for soil warming experiments see the review by Rustad et al. 2001), which will also be adopted within the Swiss COST 639 consortium, we see an urgent need of complementing these studies by works using natural thermal and N-gradients. A lot of reasoning in terms of ecosystem carbon budgets relies on carbon pools. While these are significant and measured in a series of national and international attempts, they are rarely combined with actual flux measurements or vice versa. Our survey will aggregate process rates (litter production, root production, thickness growth of trees, soil CO2-evaluation) and climate, as well as soil data. Our project contributes primarily to the working group 1 agenda of this COST action.

Integratives nachhaltiges Wildtier-management im Biosphärenpark Wienerwald

Wildtiere (Arten, Populationen, Individuen, Lebensräume, genetische Vielfalt) werden neben der Jagd von vielen anderen Landnutzungsaktivitäten beeinflusst, die sich im Wildlebensraum vielfach überlagern und oftmals miteinander konkurrieren. Insbesondere in Mehrfachnutzungs-Kulturlandschaften, wie dem Biosphärenpark Wienerwald, können die resultierenden Wechselwirkungen zwischen den Lebensraumansprüchen von Wildtieren, jagdlichen Nutzungsinteressen und anderen Landnutzungsansprüchen oftmals zu Konflikten führen, die der nachhaltigen Erhaltung heimischer Wildtierarten und ihrer Lebensräume, der Nachhaltigkeit der beteiligten Landnutzungen und einer nachhaltigen regionalen Entwicklung insgesamt abträglich sein können. Sektorale Nachhaltigkeitsansätze alleine sind unzureichend und können sogar unbeabsichtigte negative Auswirkungen auf andere Landnutzungen und auf das betreffende Ökosystem haben. Der nachhaltige Umgang mit Wildtieren kann letztlich nur gelingen, wenn alle im Wildlebensraum agierenden Nutzergruppen sich der Auswirkungen ihrer Tätigkeiten auf die Ressource 'Wildtier' sowie auf die jeweils anderen Nutzergruppen bewusst sind. Am Beispiel von 'Wildtieren und Jagd' wurden daher im Biosphärenpark Wienerwald modellhaft Konzepte, Inhalte und Instrumente für eine integrative, d. h. sektorübergreifend abgestimmte Nachhaltigkeitsbeurteilung mehrerer Landnutzergruppen entwickelt. Mittels angewandter und partizipativer Forschungsmethoden (Experteninterviews, breite Nutzerbefragungen, projektbegleitende Partizipation) wurden zentrale Schnittstellen (Antagonismen, Synergiepotenziale) zwischen Wildtieren, Jagd und weiteren regionalen Landnutzungen identifiziert, analysiert und bewertet. Als zentrales Ergebnis liegen sektorübergreifend abgestimmte Sets von Prinzipien, Kriterien und Indikatoren für ein integratives nachhaltiges Wildtiermanagement im Biosphärenpark Wienerwald vor. Die Bewertungssets dienen der Selbstbewertung wesentlicher regionaler Nutzergruppen (Forstwirtschaft, Landwirtschaft, Jagd, Freizeit- und Erholungsmanagement) und ermöglichen es diesen, jeweils eigene Einflussmöglichkeiten auf die nachhaltige Erhaltung von Wildtierarten, deren Lebensräumen und eine nachhaltige Jagd selbst zu überprüfen. Nachhaltigkeitsanforderungen anderer Nutzergruppen wurden dabei jeweils berücksichtigt. Somit wurde am Beispiel der stark vernetzten Thematik 'Umgang mit Wildtieren' erstmals der Schritt von der rein sektorbezogenen hin zu einer sektorübergreifend abgestimmten Erfassung der Nachhaltigkeit vollzogen. Weiters wurden Empfehlungen für ein integratives nachhaltiges Wildtiermanagement sowie für ein diesbezügliches Monitoring ausgearbeitet. Die Projektergebnisse sollen dazu beitragen, Wildtiere und deren Management möglichst konfliktfrei in eine nachhaltige Landnutzung im Biosphärenpark Wienerwald zu integrieren. Die Vollversion des Endberichtes samt Anhängen ist als Download-Publikation auf der Homepage der Österreichischen Akademie der Wissenschaften

Energy and Water Fluxes at the Soil Atmosphere Interface of Water Repellent soils

Water repellency (WR) plays a significant role in a large number of soils all over the world. In many regions global warming will lead to drier land surfaces and thus, increasing the likeliness of actual water repellency for such soils. The hydrological effects of WR (surface runoff, water erosion, preferential flow) have been relatively well investigated in the last decades. However, its effect on the energy balance between soil and atmosphere has not been studied yet. We postulate that global warming does not only lead to an increase in WR of soils, but WR has an impact on the energy balance and thus, will lead to a feedback on global warming. In order to test our hypothesis, we want to determine all components of the energy- and water balance between soil and atmosphere for a strongly water repellent soil. As a reference we want to repeat the same measurements for the same soil, at which the WR has been suspended by application of a surfactants. While the laboratory studies aim to give insight into more principle processes, the lysimeter (bare and with plants) and field scale studies shall give information about integrated complex natural processes. The gained knowledge shall be implemented into a numerical simulation tool for modeling water and energy balances in order to predict the effects of WR under different atmospheric conditions and physical soil properties.

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