Das Projekt "Non-destructive characterization and monitoring of root structure and function at the rhizotron and field scale using spectral electrical impedance tomography (ImpTom)" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Departement Agrar- und Lebensmittelwissenschaften, Institut für Nutztierwissenschaften, Gruppe Physiologie und Tierhaltung durchgeführt. This subproject aims at the development of spectral electrical impedance tomography (EIT) as a non-destructive tool for the imaging, characterization and monitoring of root structure and function in the subsoil at the field scale. The approach takes advantage of the capacitive properties of the soil-root interface associated with induced electrical polarization processes at the root membrane. These give rise to a characteristic electrical signature (impedance spectrum), which is measurable in an imaging framework using EIT. In the first project phase, the methodology is developed by means of controlled rhizotron experiments in the laboratory. The goal is to establish quantitative relationships between characteristics of the measured impedance spectra and parameters describing root system morphology, root growth and activity in dependence on root type, soil type and structure (with/without biopores), as well as ambient conditions. Parallel to this work, sophisticated EIT inversion algorithms, which take the natural characteristics of root system architecture into account when solving the inherent inverse problem, will be developed and tested in numerical experiments. Thus the project will provide an understanding of electrical impedance spectra in terms of root structure and function, as well as specifically adapted EIT inversion algorithms for the imaging and monitoring of root dynamics. The method will be applied at the field scale (central field trial in Klein-Altendorf), where non-destructive tools for the imaging and monitoring of subsoil root dynamics are strongly desired, but at present still lacking.
Das Projekt "Hydrogeological and hydrochemical modelling of density-driven flow in the Tiberias Basin, in particular between Ha'on and Tiberias Regions, Jordan Valley" wird vom Umweltbundesamt gefördert und von Bundesamt für die Sicherheit der nuklearen Entsorgung durchgeführt. The aim of the current research is to identify regional sources and trans-boundary flow leading to the observed salinity of Lake Tiberias (LT) -also known as the Sea of Galilee or Lake Kinneret-, and its surroundings, which is considered the only natural surface fresh water reservoir of the area. The current study will include all sources of brines in the Tiberias Basin (TB) with specific emphasis of the relationship between the brines from the Ha'on and Tiberias Regions (HTR).The tasks will be achieved by a multidisciplinary approach involving: (i) numerical modelling of density-driven flow processes (i.e., coupled heat and dissolution of evaporites), (ii) hydrochemical studies, supplemented by investigations of subsurface structures.(i) Numerical modelling will be carried out by applying the commercial software FEFLOW® (WASY, GmbH) complemented with the open source code OpenGeoSys developed at the UFZ of Leipzig (Wang et al., 2009). The final goal is to build a 3D regional-scale model of density-driven flow that will result in: (1) revealing the different interactions between fresh groundwater and natural salinity sources (2) elucidate the driving mechanisms of natural brines and brackish water body's movements.(ii) Hydrochemical study will include major, minor and, if possible, rare earth elements (REE) as well as isotope studies. The samples will be analysed at the FU Berlin and UFZ Halle laboratories. Geochemical data interpretation and inverse modelling will be supported by PHREEQC. Hydrochemical field investigations will be carried out in Tiberias basin and its enclosing heights, i.e. the Golan, Eastern Galilee and northern Ajloun in order to search for indications of the presence of deep, relic saline groundwater infested by the inferred Ha'on mother-brine. The current approaches will be supplemented by seismic and statistical data analysis as well as GIS software applications for the definition of the subsurface structures. The key research challenges are: building a 3D structural model of selected regions of TB, adapting both structural and hydrochemical data to the numerical requirements of the model; calibrating the 3D regional-scale model with observational data. The results of this work are expected to establish suitable water-management strategies for the exploitation of freshwater from the lake and from the adjacent aquifers while reducing salinization processes induced by both local and regional brines.
Das Projekt "Identification of effective process formulations for evaporation of water from bare soil" wird vom Umweltbundesamt gefördert und von Technische Universität Braunschweig, Institut für Geoökologie, Abteilung Bodenkunde und Bodenphysik durchgeführt. Describing the evaporative movement of soil water towards the soil-atmosphere interface with one-dimensional effective continuum-scale process models can be a valid approach under some conditions, but may lead to erroneous flow predictions under certain circumstances. The aim of this subproject is to explore validity limits of the Richards equation for describing bare soil evaporation in particular during stage-two evaporation, where the soil's unsaturated hydraulic conductivity and vapor diffusion in soil dominate the evaporation process. To analyze limitations arising from neglect of coupled heat and water vapor flow processes and to assess the importance of using a correct hydraulic conductivity function for liquid phase flow, we will evaluate data from a variety of evaporation scenarios by inverse modeling with effective process models. Scenarios cover experiments under transient conditions and include flow interruptions to study dynamic effects. Data will be provided by virtual realities obtained by comprehensive forward modeling by SP2, small lysimeter experiments under laboratory and field conditions, and a joint lysimeter experiment (SP3). In the inverse evaluations, we will start with the full Philip-de Vries model and extensions for non-equilibrium water flow and simplify it stepwise towards the Richards equation in order to assess which model complexity is necessary to adequately describe the measurement data. Our particular interest lies in (i) identifying the relative contributions of liquid and vapor water flow to the total water flow near the surface, (ii) determining the time at which evaporation shifts from stage-one to stage-two, (iii) determining the position of the vaporization plane during stage-two evaporation, and (iv) quantifying the range of conditions where effective process descriptions can be used in practical situations to correctly predict the water fluxes to the atmosphere.
Das Projekt "Promotionsstudiengang: Biodiversität und Gesellschaft - Vertrauen und Reziprozität bei der marktbasierten Bereitstellung öffentlicher Güter - Experimentelle Belege und Anwendungen auf Naturschutzauktionen" wird vom Umweltbundesamt gefördert und von Georg-August-Universität Göttingen, Wirtschaftswissenschaftliche Fakultät, Professur für Wirtschaftspolitik und Mittelstandsforschung durchgeführt. Zahlungen für Ökosystemdienstleistungen (Payments for Ecosystem Services - PES) und auktionsbasierte Vergabeverfahren sind ein wichtiges und innovatives Instrument im Kampf gegen den fortwährenden Verlust von biologischer Vielfalt. Basierend auf einem Vertrag zwischen einem Leistungserbringer und einem öffentlichen oder privaten Leistungsempfänger, der die Naturschutzleistung entlohnt, können bestimmte Vorgaben der Landschaftspflege oder der agrarwirtschaftlichen Bearbeitung verbindlich festgelegt werden. Die Vorteile von PES liegen in dem direkten monetären Anreiz zur Bereitstellung von Naturschutzleistungen und zudem in der Möglichkeit, ein Niveau an Umweltschutz und -qualität jenseits des von der Umweltgesetzgebung sichergestellten Mindestniveaus zu implementieren. Der Nachteil liegt in der hohen Informationsasymmetrie in der Vertragsbeziehung, welche einerseits dem Umweltgut als Vertragsgegenstand und andererseits der Natur ökonomischen Handelns geschuldet ist. Projektthema ist die Analyse der interdependenten Beziehung von Kompetitivität und Vertragserfüllung und das Aufzeigen der Relevanz von Vertrauen und Reziprozität in Verträgen über Umweltgüter. Auf diese Weise wird ein Beitrag zu der umfangreichen und multidisziplinären Literatur über Zahlungen für Ökosystemdienstleistungen und Naturschutzauktionen geleistet. Während der vergangenen 25 Jahre habe Praktiker und Wissenschaftler unser Verständnis der Funktionsweise von Ausschreibungen zur Allokation von Zahlungen für Ökosystemdienstleistungen konstant verbessert und erweitert. Ein Großteil der Forschungsaktivität war jedoch auf die Auktionsmetrik und das Bieterverhalten gerichtet, wohingegen die resultierende Vertragsbeziehung zwischen Programmverwaltern (den Käufern) und Landbesitzern (den Ausführenden) weitgehend unbeachtet blieb. Wie bewiesen wird, ist jedoch genau diese Beziehung der Schlüssel für ein erfolgreiches marktbasiertes Naturschutzprogramm. Vertrauen und Reziprozität sind für die Überwindung von asymmetrischer Information in kompetitiv alloziierten PES-Verträgen von herausragender Bedeutung. Anhand eines extra entwickelten, zweistufigen experimentellen Testszenarios wird der Entscheidungsprozess in der inversen Auktion und in der anschließenden Vertragserfüllung in der kontrollierten Laborumgebung simuliert. In einem ersten Experiment kann auf Basis dieses Untersuchungsdesigns gezeigt werden, dass die Informations- und Anreizkonstellation in Naturschutzauktionen ein erhöhtes Risiko für vorvertragliche adverse Selektion, opportunistisches Verhalten bei Vertragserfüllung und somit suboptimale Ergebnisse birgt. Das Marktversagen kann jedoch durch eine vertrauensstiftende Institution, wie zum Beispiel Kommunikation zwischen Käufern und Verkäufern, verhindert werden. Persönliche Interaktion veranlasst Marktteilnehmer ihr individuell-rationales Verhalten zugunsten einer sozial-verträglicheren Verhaltensweise zu ändern. usw.
Das Projekt "Fine Structure of the Stably Stratified Atmospheric Boundary Layer in Antarctica" wird vom Umweltbundesamt gefördert und von Technische Universität Braunschweig, Institut für Luft- und Raumfahrtsysteme durchgeführt. As element of the cooperation between the Inst. f. Luft- und Raumfahrtsysteme, Techn. Univ. Braunschweig (ILR), and the British Antarctic Survey (HAS) in total three small meteorological flight robots (M2AV) are sent to Halley station. There the fully autonomously operating aircraft (developed at the ILR) are going to measure the turbulent characteristics of the stable atmospheric boundary layer (SBL) above the ice shelf. These in situ measurements are then used to verify, support and complete the already installed BAS sodar systems and the meteorological tower. Main research goal is the fine structure of the SBL especially regarding thin layers, intermittent and fossil turbulence, and (solitary) waves. The use of structure functions, multi-resolution co-spectra and wavelet analysis give information on the spectral characteristics of turbulent structure and transport within the layered SBL. Applying inverse models to the observed data, gradients, divergence and energy fluxes are calculated in order to quantify the turbulent energy transfer between SBL and surface, and between individual layers. Furthermore the horizontal representativeness of the installed remote sensing systems is validated. In the preceding project PSBL a large quality-controlled database from Helipod flights over Arctic sea ice (Polarstern campaigns ARK-XI, ARK-XII and ARK-XIX) was already created. This data base is now used to analyse the resemblance and difference between the SBL over shelf ice (Antarctic) and sea ice (Arctic). The project will contribute to the understanding of specific elements and processes of the SBL particularly under polar conditions. At the beginning of the project all experiments and journals will be already completed. Thus we apply only for man power to analyse the unique data sets from Halley station and M2AVs.
Das Projekt "Interaktion Strasse-Hangstabilität: Monitoring und Rückwärtsrechnung" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule (ETH) Zürich, Institut für Geotechnik durchgeführt.
Das Projekt "Regulation of AtPGP1-mediated auxin transport by phosphorylation" wird vom Umweltbundesamt gefördert und von Universität Zürich, Institut für Pflanzenbiologie, Abteilung Physiologie und Mikrobiologie durchgeführt. Auxin - principally indole-3-acetic acid (IAA) - has proven as unique signaling molecule virtually controlling all plant developmental processes. Recent research has concentrated on the fascinating feature auxin being transported in a directed or polar fashion. Polar auxin transport (PAT) is regulated at the cellular level and is apparently both a product and determinant of cellular polarity. Auxin unloading is thought to be mediated by protein complexes that are characterized by members of the p-plycoprotein (PGP) and pin-shaped (PIN) protein families. The establishment of auxin gradients is controlled by reversible protein phosphorylation, however, the individual targets of protein kinases and phosphatases are unknown. Several lines of evidence point to components of auxin efflux complexes and/or NPA-binding proteins as targets of phosphorylation. While PIN proteins are apparently unlikely candidates two findings favor PGP as targets: PGP1 has been shown recently to catalyze the primary active export of auxin and to be modulated by NPA binding. Moreover, in a recent phosphoproteomic approach, PGP1 has been demonstrated to be phosphorylated in conserved phosphorylation sites in a so-called regulatory linker domain. This domain is known to modulate the activity mammalian PGPs by phosphorylation via PKC. In this project we envisage to demonstrate that PGP1-mediated auxin transport is modulated by phosphorylation in its regulatory linker domain. Phosphoproteomic data, a yeast-based mutant screen, and site directed mutagenesis will be used to determine the impact of phosphorylation on transport activity. The outcome of the yeast work will allow us to engineer relevant phosphorylation sites in the linker domain of PGP1 that alter protein activity and/or location. Additionally, TILLING technology will be used to identify relevant point mutations in the linker domain. Finally, in order to identify plant-borne kinases/phosphatases responsible for (de)phosphorylation of PGP1, a classical yeast two-hybrid screen using the linker domain as bait will be carried out. In an inverse approach, the phosphorylation status of PGP1 will be upon will be determined biochemically and by mass spectrometry applying physiological, chemical and genetic tools. The outcome should provide a deep insight into the regulation of auxin transport via PGPs and the establishment of local auxin gradients controlling virtually all steps of plant development. Transfer of this knowledge might later on open new strategies for the directed genetic or chemical manipulation of plant development.
Das Projekt "C-STAR: Coastal Sediment Transport Assessment Using SAR Imagery" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Meereskunde (IfM) durchgeführt. C-STAR was a joint European project, carried out by ten partner institutions in the Netherlands, Belgium, Great Britain, and Germany; financially supported by the Commission of the European Community as a part of the Marine Science and Technology (MAST) program under contract no. MAS3-CT95-0035.. C-STAR was devoted to an improved theoretical understanding of the radar imaging of underwater bottom topography in tidal waters and to an investigation of the potential of inverse models which retrieve topographic maps from radar images, for morphological research and monitoring applications. C-STAR included a major field experiment off the Dutch coast, which was carried out in April, 1996. The activities of the Satellite Oceanography group of the University of Hamburg within C-STAR focused on the improvement of theoretical models for the hydrodynamic wave-current interaction and for the radar backscattering at the sea surface, which appears to be described relatively well by the existing composite surface model.
