Das Projekt "Identification of groundwater nitrogen point source contribution through combined distribute temperature sensing and in-situ UV photometry" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Gießen, Institut für Landschaftsökologie und Ressourcenmanagement, Professur für Landschafts-, Wasser- und Stoffhaushalt.Agriculture is the major contributor of nitrogen to ecosystems, both by organic and inorganic fertilizers. Percolation of nitrate to groundwater and further transport to surface waters is assumed to be one of the major pathways in the fate of this nitrogen. The quantification of groundwater and associated nitrate flux to streams is still challenging. In particular because we lack understanding of the spatial distribution and temporal variability of groundwater and associated NO3- fluxes. In this preliminary study we will focus on the identification and quantification of groundwater and associated nitrate fluxes by combining high resolution distributed fiber-optic temperature sensing (DTS) with in situ UV photometry (ProPS). DTS is a new technique that is capable to measure temperature over distances of km with a spatial resolution of ca1 m and an accuracy of 0.01 K. It has been applied successfully to identify and quantify sources of groundwater discharge to streams. ProPS is a submersible UV process photometer, which uses high precision spectral analyses to provide single substance concentrations, in our case NO3-, at minute intervals and a detection limit of less than 0.05 mg l-1 (ca.0.01 mg NO3--Nl-1). We will conduct field experiments using artificial point sources of lateral inflow to test DTS and ProPS based quantification approaches and estimate their uncertainty. The selected study area is the Schwingbach catchment in Hessen, Germany, which has a good monitoring infrastructure. Preliminary research on hydrological fluxes and field observations indicate that the catchment favors the intended study.
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Nadelwald aus dem ATKIS Basis-DLM
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Die gesamte Landesfläche des Saarlandes wird lückenlos in Forstreviere unterteilt. Innerhalb dieser Flächen ist die Leiterin / der Leiter des Forstrevieres für die Bewirtschaftung des Staatswaldes und des vertraglich betreuten Kommunal- und Privatwaldes zuständig. Darüber hinaus gibt es kommunale und private Waldbesitzer, die ihren Wald in Eigenregie bewirtschaften. Auf deren Flächen nehmen Mitarbeiter des SaarForst Landesbetriebes nur in begrenztem Umfang zumeist hoheitliche Aufgaben wahr. Die Grenzen der Forstreviere wurden auf Basis der TK25 digitalisiert und decken sich daher nicht in allen Fällen mit den Grenzen der Waldbestände.
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Dieser Datensatz enthält NavLog Wegeklassen 1 und 2 im saarländischen Wald.
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Bei Unfällen im Wald und in der freien Landschaft kommt dem Herbeiführen von Rettungskräften eine besondere Bedeutung zu. Die sonst üblichen Bezeichnungn von Straßen und Hausnummern sind hier nicht zu finden, Flurnamen oder betriebliche Bezeichnungen von Waldstücken oder Standorten werden oft nicht verstanden und daher fehlerhaft interpretiert. Aus dieser Situation heraus wurde länderübergreifend ein System geschaffen, bei dem Rettungskräfte zu einem eindeutig bezeichneten Rendezvous Punkt bestellt werden. Diese Punkte liegen so in der Landschaft, dass sie eindeutig beschreibbar, und auch von potenziellen Unfallstandorten in Wald und Landschaft möglichst kurz erreichbar sind.
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Darstellung der Staats-, Kommunal- und Privatwälder im Saarland.
Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Der Dienst stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.
Das Projekt "Biopores in the subsoil: Formation, nutrient turnover and effects on crops with distinct rooting systems (BioFoNT)" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Bonn, Institut für Organischen Landbau.Perennial fodder cropping potentially increases subsoil biopore density by formation of extensive root systems and temporary soil rest. We will quantify root length density, earthworm abundance and biopore size classes after Medicago sativa, Cichorium intybus and Festuca arundinacea grown for 1, 2 and 3 years respectively in the applied research unit's Central Field Trial (CeFiT) which is established and maintained by our working group. Shoot parameters including transpiration, gas exchange and chlorophyll fluorescence will frequently be recorded. Precrop effects on oilseed rape and cereals will be quantified with regard to crop yield, nutrient transfer and H2-release. The soil associated with biopores (i.e. the driloshpere) is generally rich in nutrients as compared to the bulk soil and is therefore supposed to be a potential hot spot for nutrient acquisition. However, contact areas between roots and the pore wall have been reported to be low. It is still unclear to which extent the nutrients present in the drilosphere are used and which potential relevance subsoil biopores may have for the nutrient supply of crops. We will use a flexible videoscope to determine the root-soil contact in biopores. Nitrogen input into the drilosphere by earthworms and potential re-uptake of nitrogen from the drilosphere by subsequent crops with different rooting systems (oilseed rape vs. cereals) will be quantified using 15N as a tracer.
Das Projekt "The iron-snow regime in Fe-FeS cores: a numerical and experimental approach" wird/wurde ausgeführt durch: Helmholtz-Zentrum Dresden-Roßendorf, Institut für Fluiddynamik.In the Earth, the dynamo action is strongly linked to core freezing. There is a solid inner core, the growth of which provides a buoyancy flux that drives the dynamo. The buoyancy in this case derives from a difference in composition between the solid inner core and the fluid outer core. In planetary bodies smaller than the Earth, however, this core differentiation process may differ - Fe may precipitate at the core-mantle boundary (CMB) rather than in the center and may fall as iron snow and initially remelt with greater depth. A chemical stable sedimentation zone develops that comprises with time the entire core - at that time a solid inner core starts to grow. The dynamics of this system is not well understood and also whether it can generate a magnetic field or not. The Jovian moon Ganymede, which shows a present-day magnetic dipole field, is a candidate for which such a scenario has been suggested. We plan to study this Fe-snow regime with both a numerical and experimental approach. In the numerical study, we use a 2D/3D thermo-chemical convection model that considers crystallization and sinking of iron crystals together with the dynamics of the liquid core phase (for the 3D case the influence of the rotation of the Fe snow process is further studied).The numerical calculations will be complemented by two series of experiments: (1) investigations in metal alloys by means of X-ray radioscopy, and (2) measurements in transparent analogues by optical techniques. The experiments will examine typical features of the iron snow regime. On the one hand they will serve as a tool to validate the numerical approach and on the other hand they will yield important insight into sub-processes of the iron snow regime, which cannot be accessed within the numerical approach due to their complexity.
Das Projekt "Redox processes along gradients" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Bayreuth, Lehrstuhl für Hydrologie, Limnologische Forschungsstation.The relevance of biogeochemical gradients for turnover of organic matter and contaminants is yet poorly understood. This study aims at the identification and quantification of the interaction of different redox processes along gradients. The interaction of iron-, and sulfate reduction and methanogenesis will be studied in controlled batch and column experiments. Factors constraining the accessibility and the energy yield from the use of these electron acceptors will be evaluated, such as passivation of iron oxides, re-oxidation of hydrogen sulfide on iron oxides. The impact of these constraints on the competitiveness of the particular process will then be described. Special focus will be put on the evolution of methanogenic conditions in systems formerly characterized by iron and sulfate reducing condition. As methanogenic conditions mostly evolve from micro-niches, methods to study the existence, evolution and stability of such micro-niches will be established. To this end, a combination of Gibbs free energy calculations, isotope fractionation and tracer measurements, and mass balances of metabolic intermediates (small pool sizes) and end products (large pool sizes) will be used. Measurements of these parameters on different scales using microelectrodes (mm scale), micro sampling devices for solutes and gases (cm scale) and mass flow balancing (column/reactor scale) will be compared to characterize unit volumes for organic matter degradation pathways and electron flow. Of particular interest will be the impact of redox active humic substances on the competitiveness of involved terminal electron accepting processes, either acting as electron shuttles or directly providing electron accepting capacity. This will be studied using fluorescence spectroscopy and parallel factor analysis (PARAFAC) of the gained spectra. We expect that the results will provide a basis for improving reactive transport models of anaerobic processes in aquifers and sediments.
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