Die Daten sind aus dem Projekt „Bilanzierung des Grundwasserdargebotes für das Land Brandenburg“ (HGN-Gutachten 2021) im Zusammenhang mit den Daten zum Projekt „Hydroisohypsenplan 2017“ aus dem Umweltplan-Gutachten (2017) aggregiert worden. Auf Grundlage stichtagsbezogener Grundwasser-/ Oberflächenwasserstandsdaten des Frühjahres 2015 erfolgte über das Interpolationsverfahren „Detrended Kriging/Residual Kriging“ in Kombination mit einer geohydraulischen Modellierung, die Berechnung der Hydroisohypsen (Linien gleicher Grundwasserstände auf NHN bezogen). Für die Darstellung der unterirdischen Einzugsgebiete wurden zuerst die oberirdischen Einzugsgebiete ausgegrenzt. Danach erfolgte die Ausgrenzung der unterirdischen Einzugsgebiete in Ableitung der o. g. Hydrodynamik aus dem Frühjahr 2015. Unterirdische Einzugsgebiete werden auch Grundwassereinzugsgebiete genannt. Die Daten sind aus dem Projekt „Bilanzierung des Grundwasserdargebotes für das Land Brandenburg“ (HGN-Gutachten 2021) im Zusammenhang mit den Daten zum Projekt „Hydroisohypsenplan 2017“ aus dem Umweltplan-Gutachten (2017) aggregiert worden. Auf Grundlage stichtagsbezogener Grundwasser-/ Oberflächenwasserstandsdaten des Frühjahres 2015 erfolgte über das Interpolationsverfahren „Detrended Kriging/Residual Kriging“ in Kombination mit einer geohydraulischen Modellierung, die Berechnung der Hydroisohypsen (Linien gleicher Grundwasserstände auf NHN bezogen). Für die Darstellung der unterirdischen Einzugsgebiete wurden zuerst die oberirdischen Einzugsgebiete ausgegrenzt. Danach erfolgte die Ausgrenzung der unterirdischen Einzugsgebiete in Ableitung der o. g. Hydrodynamik aus dem Frühjahr 2015. Unterirdische Einzugsgebiete werden auch Grundwassereinzugsgebiete genannt.
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Das Projekt "Steady-State Dilution and Mixing-Controlled Reactions in Three-Dimensional Heterogeneous Porous" wird vom Umweltbundesamt gefördert und von Eberhard Karls Universität Tübingen, Zentrum für Angewandte Geowissenschaften (ZAG), Arbeitsgruppe Hydrogeology durchgeführt. Understanding transport of contaminants is fundamental for the management of groundwater re-sources and the implementation of remedial strategies. In particular, mixing processes in saturated porous media play a pivotal role in determining the fate and transport of chemicals released in the subsurface. In fact, many abiotic and biological reactions in contaminated aquifers are limited by the availability of reaction partners. Under steady-state flow and transport conditions, dissolved reactants come into contact only through transverse mixing. In homogeneous porous media, transverse mixing is determined by diffusion and pore-scale dispersion, while in heterogeneous formations these local mixing processes are enhanced. Recent studies investigated the enhancement of transverse mixing due to the presence of heterogeneities in two-dimensional systems. Here, mixing enhancement can solely be attributed to flow focusing within high-permeability inclusions. In the proposed work, we will investigate mixing processes in three dimensions using high-resolution laboratory bench-scale experiments and advanced modeling techniques. The objective of the proposed research is to quantitatively assess how 3-D heterogeneity and anisotropy of hydraulic conductivity affect mixing processes via (i) flow focusing and de-focusing, (ii) increase of the plume surface, (iii) twisting and intertwining of streamlines and (iv) compound-specific diffusive/dispersive properties of the solute species undergoing transport. The results of the experimental and modeling investigation will allow us to identify effective large-scale parameters useful for a correct description of conservative and reactive mixing at field scales allowing to explain discrepancies between field observations, bench-scale experiments and current stochastic theory.
Das Projekt "AURORa - Investigation of the Radar Backscatter of Rain Impinging on the Ocean Surface" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Meereskunde (IfM) durchgeführt. Over land, observations of rain rates are more or less operational. To obtain information about precipitation at the coastal zones, weather radars are used. However, over the oceans, especially away from the main shipping routes, no direct precipitation measurements are performed. In these regions, satellite data can provide information about precipitation events. Satellites deploying passive and active microwave sensors can operate independently of cloud cover and time of day. Passive microwave sensors give crude estimates of rain rates over large areas but cannot resolve small-scale rain events of short duration as are often observed in the tropics, for example. Active microwave sensors with high resolutions, such as synthetic aperture radars can provide more reliable information. Though the effect of rain on the atmosphere is a very topical area of research, the radar backscattering mechanisms at the water surface during rain events combined with wind are still not well understood. The purpose of this project is to investigate the radar backscattering from the water surface in the presence of rain and wind in order to interpret satellite radar data produced by active microwave sensors. Furthermore, the results should be embedded into models of the radar backscattering from the water surface to allow for estimating rain rates by using satellite data. Research topics: Rain impinging on a water surfaces generates splash products including crowns, cavities, stalks and secondary drops, which do not propagate, and ring waves and subsurface turbulence. We are investigating this phenomena at the wind-wave tank of the University of Hamburg. The tank is fitted with an artificial rain simulator of 2.3 m2 area mounted 4.5 m over the water surface. Rain drops of 2.1 and 2.9 mm in diameter with rain rates up to 100 mm/h have been produced. Wind with speeds 10 m/s and monomolecular slicks act on the water surface. The influence of the rain on the water surface is measured with a resistance type wire gauge, a two dimensional laser slope gauge and an coherent 9.8 GHz (x band) continuous wave scatterometer operating at VV-, HH- and HV-polarization. The influence of rain below the water surface is measured with colored raindrops which are observed with a video camera to investigate the turbulent motion and the depth of the mixed layer. At the North Sea Port of Buesum in Germany, a scatterometer operating at all polarizations and five frequencies will be mounted during summer of this year. The radar backscatter of the sea surface during rain events will be measured in combination with meteorological observations. With help of these measurements, existing radar backscatter models of the water surface will be improved for the presence of rain events. To validate the improved models, ERS-2 SAR-images will be compared with weather radar data.
Das Projekt "14C content of specific organic compounds in subsoils" wird vom Umweltbundesamt gefördert und von Universität zu Köln, Institut für Geologie und Mineralogie durchgeführt. Organic matter (OM) composition and dynamic in subsoils is thought to be significantly different from those in surface soils. This has been suggested by increasing apparent 14C ages of bulk soil OM with depth suggesting that the amount of fresh, more easily degradable components is declining. Compositional changes have been inferred from declining ä13C values and C/N ratios indicative for stronger OM transformation. Beside these bulk OM data more specific results on OM composition and preservation mechanisms are very limited but modelling studies and results from incubation experiments suggest the presence and mineralization of younger, 'reactive carbon pool in subsoils. Less refractory OM components may be protected against degradation by interaction with soil mineral particles and within aggregates as suggested by the very limited number of more specific OM analysis e.g., identification of organic compound in soil fractions. The objective of this project is to characterize the composition, transformation, stabilization and bioavailability of OM in subsurface horizons on the molecular level: 1) major sources and compositional changes with depth will be identified by analysis of different lipid compound classes in surface and subsoil horizons, 2) the origin and stabilization of 'reactive OM will be revealed by lipid distributions and 14C values of soil fractions and of selected plant-specific lipids, and 3) organic substrates metabolized by microbial communities in subsoils are identified by distributional and 14C analysis of microbial membrane lipids. Besides detailed analyses of three soil profiles at the subsoil observatory site (Grinderwald), information on regional variability will be gained from analyses of soil profiles at sites with different parent material.
Das Projekt "From subsurface structures to functions and texture - linking virtual realities and experiments at the plot and hillslope scales" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Institut für Wasser und Gewässerentwicklung, Bereich Hydrologie durchgeführt. This project will explore the interplay between soil water, tracer and soil heat budgets depending on the prevailing context and develop advanced approaches for their coupled treatment within the subsurface domains of an EFU (the least entity of the CAOS model). Based on an improved understanding of the fingerprints of vertical preferential flow in the water, mass and heat transport in the unsaturated zone we will derive suitable closure relations that account for these fingerprints in the unsaturated subsurface domain of an EFU during rainfall driven conditions. We will furthermore derive descriptions for water, mass and heat budgets in the unsaturated subsurface domain during energy driven conditions and derive the necessary constitutive relations that account for the effect of soil heterogeneity on storage of water, mass and energy based on virtual experiments. Next we will explore coupled water and heat transport in the saturated subsurface domain with special emphasis on groundwater surface water exchange and derive process descriptions of minimum adequate complexity. Furthermore we will contribute to an optimal combination of soil physical and geophysical methods for exploring near subsurface lateral structures at the hillslope scale in joined work task with Project F.
Das Projekt "Integrated water resources modeling and its uncertainty analysis for coastal watersheds under climate and land-use change" wird vom Umweltbundesamt gefördert und von Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften (IBG), IBG-3 Agrosphäre durchgeführt. It has been shown that three-dimensional groundwater dynamics may have strong influence on the mass-and energy balance (MEB) of the landsurface. On the other hand, the landsurface MEB, including processes such as evapotranspiration, plays a key role in groundwater recharge. Therefore, changes in land-use type and patterns may have significant influence on the MEB and groundwater recharge in the future, because evapotranspiration is strongly determined by the vegetation cover. This illustrates the reciprocity in the coupled hydrologic and energy cycles. Without explicit inclusion of groundwater dynamics, MEB calculations are burdened with significant inaccuracies and uncertainties (and vice versa), and may lead to wrong predictions. The goal is to study and quantify the influence of groundwater dynamics on the MEB of the landsurface over large spatial and temporal scales and to derive estimates of groundwater recharge and evapotranspiration influenced by future climate and land-use change. The proposed study will work under the scientific exemplar that the subsurface-landsurface system must be represented in a physically consistent and integrated fashion. This will be achieved by a fusion of theoretical approaches and measured data. An existing integrated, high-performance computing simulation platform for MEB calculations of the subsurface-landsurface system will be improved and applied to the large scale Luanhe watershed in China for validation and prognostic purposes. For the first time, the entire system from the water table across the landsurface will be considered, which will lead to more accurate predictions of the system state. The MEB at the landsurface is governed by complex processes including plant transpiration. Until now, these processes are approximated via ad-hoc empirical approaches that have not been validated adequately using measurements. In this study, a more complete transpiration and root water uptake model will be implemented to account for e.g., variable root density distributions depending on subsurface moisture conditions that are commonly neglected and optimized stomatal resistance parameterizations. These approaches will enter directly into the integrated simulation platform. In a validation exercise, the simulation platform will be applied to the Luanhe watershed. Groundwater recharge - a parameter of major interest in the study region - will be extracted and the influence of climate and land-use change will be investigated. This will include scenario simulations of future climate and landuse changes in the region. As a demonstration, high-resolution, long-term forecasts of the MEB of the Luanhe catchment will be generated. These results will provide the foundation for management and mitigation strategies of potential consequences of climate and land-use change, which is the primary subject of the Chinese research team.
Das Projekt "Linking internal pattern dynamics and integral responses - Identification of dominant controls with a strategic sampling design" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. In hydrology, the relationship between water storage and flow is still fundamental in characterizing and modeling hydrological systems. However, this simplification neglects important aspects of the variability of the hydrological system, such as stable or instable states, tipping points, connectivity, etc. and influences the predictability of hydrological systems, both for extreme events as well as long-term changes. We still lack appropriate data to develop theory linking internal pattern dynamics and integral responses and therefore to identify functionally similar hydrological areas and link this to structural features. We plan to investigate the similarities and differences of the dynamic patterns of state variables and the integral response in replicas of distinct landscape units. A strategic and systematic monitoring network is planned in this project, which contributes the essential dynamic datasets to the research group to characterize EFUs and DFUs and thus significantly improving the usual approach of subdividing the landscape into static entities such as the traditional HRUs. The planned monitoring network is unique and highly innovative in its linkage of surface and subsurface observations and its spatial and temporal resolution and the centerpiece of CAOS.