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 "Soil aeration - the key factor of oak decline in Southwest Germany?" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Geo- und Umweltnaturwissenschaften, Professur für Bodenökologie durchgeführt. Many research efforts to identify the key factors of oak decline in Europe conclude that it is a 'complex disease'. This result can hardly be falsified because of its fuzziness. A significant contribution of pathogene fungi is not without controversy, because the primary pathogenicity is not proven (Johnsson, 2004). Our starting point is the resarch of Gaertig et al. (2002) who found that on a spatial integration level of 28 oak stands in Baden-Wuerttemberg the symptoms of oak health are significantly correlated with soil aeration. Large-scale changes of soil structure in oak stands during the last decades can be attributed to the mechanization of logging (Vossbrink and Horn, 2004) as well as to a decrease of earthworm activity in acidified soils. In the proposed project we want to establish a relationship between roots and aeration-relevant parameters in a three-dimensional space. This laborious procedure is necessary because the soil-air access is highly heterogeneous and by this way forms a three-dimensional pattern. This makes one-dimensional models unefficient. By modelling the soil air access in a three-dimensional space we want to test the aeration hypothesis. Important indicators of rooting are clustering of fine roots, necrosis, or space discrimination. By assessing simultaneously soil-chemical and soil-physical parameters in the same spatial resolution, alternative hypotheses can be tested. As modelling tools point statistics, non parametric regression (GAM), and a three dimensional solution of the instationary gas-diffusion equation will be used.
Das Projekt "Sub project:The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Hydrologie durchgeführt. Strong evidence exists that the oxidation of H2S by ferric (oxyhydr)oxides occurs also in ground water systems and may exert a major role for the sulphur and iron cycle and in particular for the electron and carbon flow in aquifers. To date, no systematic study has been performed that allows to quantitatively assess its significance in such systems. This project aims to fill this gap of knowledge. The extent of the reaction depends on mineral reactivity, which we hypothesize can be expressed in terms of a generalized kinetic model for the full pH range of environmental relvance. This model accounts for the adsorption of H2S at lower pH values and of HS- at circumneutral pH to the neutral ferric (oxyhydr)oxide surface to form the reactive species FeSH. Variations in reactivity may be caused by intrinsic factors such as surface acidity of the iron mineral and solution composition, such as ionic strength and competition with other ions. The overall goals of this project therefore are to demonstrate the validity of this approach in order to quantify the kinetics for abiotic anaerobic H2S oxidation by ferric (oxyhydr)oxides, and to elucidate the role of this process as a precursor reaction for further microbial transformation of sulphur species in the aquifer.
Das Projekt "A8:Transporte und Flüsse durch die Bodengrenzschicht" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum für Ozeanforschung Kiel (GEOMAR) durchgeführt. The major goal of this new subproject is to estimate transport and fluxes of solutes between the bottom boundary layer, the stratified interior ocean and the ocean mixed layer on the continental slope and shelf regions of the Peruvian and Mauritanian Oxygen Minimum Zones (OMZ). The objectives will be achieved by estimating diapycnal and advective fluxes using two different methodological approaches: The first is basedon the measurement of the radium isotope distribution in sediments and in the water column. The second approach will use a combination of oceanographic measuring systems for the determination of turbulences, currents and hydrography. Subproject A8 will contribute to the understanding of the solute budget of the OMZ's and establishes a link between the benthic and pelagic research foci within the SFB 754.
Das Projekt "Analysis and modeling of soil shrinkage and swelling dynamics as a function of predrying intensity and frequency and its influence on soil hydraulic properties" wird vom Umweltbundesamt gefördert und von Universität Kiel, Institut für Ökosystemforschung durchgeführt. Knowledge about changes in soil pore structure during shrinkage and/or swelling processes improves the understanding and prediction of water flow and solute transport. The rearrangement of soil particles and aggregates modifies the original pore size distribution, and especially forms soil cracks. Soil cracks lead to a non-uniform soil structure and improve macropore flux. However, the geometry of soil cracks within the soil matrix upon wetting/drying cycles and its influence on hydraulic properties is not clear. Therefore, in this study, we investigate the changes of the geometry of soil cracks and of two-dimension shrinkage (i.e. vertical and horizontal) under shrinkage/swelling frequency and intensity and evaluate how far they influence hydraulic soil properties.
Das Projekt "Upwind: Development of Improved Wind Turbine Noise Prediction Tools for Low Noise Airfoil Design" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Aerodynamik und Gasdynamik durchgeführt. The noise regulations of various countries urge wind turbine manufacturers to reduce the aerodynamical noise emission of their turbines. To reduce the greenhouse gas emission, wind energy has been put in a very front position. EWEA estimates 12percent of worlds energy may come from wind turbines by the year 2020 (approx. 1,260,000 MW). This means wider deployment of wind turbines, at lower wind speed sites i.e. close to people & transmission lines. To reduce the transmission cost between production site and customer, onshore installations are still a cheaper solution. One of the biggest barriers for developing onshore turbines is the noise which has a negative impact on people's daily life. Thus, the goal of developing onshore wind turbines is to design silent wind turbines and silent wind farms and at the same time have a good aerodynamic efficiency. Noise emitted from an operating wind turbine can be divided into two parts, mechanical noise and flow induced noise. Mechanical noise can sufficiently be reduced by conventional engineering approaches but flow-induced noise is more complex and need more focus. The noise mechanisms associated with flow-induced noise emission have different sources. These are, inflow turbulence noise, tip noise, laminar boundary layer separation noise, blunt trailing-edge noise (BTE) and for turbulent boundary-layer trailing-edge interaction noise (TBL-TE). Acoustic field measurements within the European research project SIROCCO showed that the TBL-TE noise is the most dominant noise mechanism for modern wind turbines. Thus, accurate prediction and reduction of the TBL-TE noise is the main focus of the acoustics airfoil design methods for wind turbine rotor blade. For developing 'silent' airfoils, a routinely design fast, less expensive and accurate prediction methodology is desired. In this respect, simplified theoretical model would be the first candidate, and therefore the main goal is development of an accurate and efficient noise prediction model for the low noise wind turbine blade design.
Das Projekt "The Water, Energy and Food Security Nexus" wird vom Umweltbundesamt gefördert und von Fachhochschule Köln, Institut für Technologie- und Ressourcenmanagement in den Tropen und Subtropen (ITT) durchgeführt. In order to understand the interlinked problems in the Nexus (Latin = connection, linkage, interrelation) of water, energy and food security, close cooperation between scientists and practitioners from different fields is necessary. The present and future challenge of a reliable supply with water, energy and food is an example, where isolated considerations do not lead to viable solutions. Sustainable action and meaningful research in these highly interconnected fields require a holistic and comprehensive perspective and a new approach. In this sense, a collaborative research structure with a holistic view on the Nexus of Water, Energy and Food security was established in 2013 at the Cologne University of Applied Sciences. The project bundles some of the research efforts of 11 professors from different faculties and institutes. The researchers jointly work on initiating new cooperation projects with partners from industry, academia and civil society. Together they aim at exploring new technologies and applying new approaches to solve major issues of efficiency and sustainability in resource use.
Das Projekt "TRansitions to the Urban Water Services of Tomorrow (TRUST)" wird vom Umweltbundesamt gefördert und von IWW Rheinisch-Westfälisches Institut für Wasserforschung gemeinnützige GmbH durchgeführt. The European project initiative TRUST will produce knowledge and guidance to support TRansitions to Urban Water Services of Tomorrow, enabling communities to achieve sustainable, low-carbon water futures without compromising service quality. We deliver this ambition through close collaboration with problem owners in ten participating pilot city regions under changing and challenging conditions in Europe and Africa. Our work provides research driven innovations in governance, modelling concepts, technologies, decision support tools, and novel approaches to integrated water, energy, and infrastructure asset management. An extended understanding of the performance of contemporary urban water services will allow detailed exploration of transition pathways. Urban water cycle analysis will include use of an innovative systems metabolism model, derivation of key performance indicators, risk assessment, as well as broad stakeholder involvement and an analysis of public perceptions and governance modes. A number of emerging technologies in water supply, waste and storm water treatment and disposal, in water demand management and in the exploitation of alternative water sources will be analysed in terms of their cost-effectiveness, performance, safety and sustainability. Cross-cutting issues include innovations in urban asset management and water-energy nexus strengthening. The most promising interventions will be demonstrated and legitimised in the urban water systems of the ten participating pilot city regions. TRUST outcomes will be incorporated into planning guidelines and decision support tools, will be subject to life-cycle assessment, and be shaped by regulatory considerations as well as potential environmental, economic and social impacts. Outputs from the project will catalyse transformation change in both the form and management of urban water services and give utilities increased confidence to specify innovative solutions to a range of pressing challenges.
Das Projekt "SOCIOEC - Socio economic effects of management measures of the future CFP" wird vom Umweltbundesamt gefördert und von Universität zu Kiel, Institut für Volkswirtschaftslehre, Lehrstuhl für Umwelt-, Ressourcen- und Ökologische Ökonomik durchgeführt. SOCIOEC is an interdisciplinary, European wide project bringing together scientists from several fisheries sciences with industry partners and other key stakeholders to work in an integrated manner on solutions for future fisheries management, that can be implemented at a regional level. The central concept is to provide a mechanism for developing measures that are consistent with the overarching sustainability objectives of the EU, and that can provide consensus across all stakeholders. The first step will be to develop a coherent and consistent set of management objectives, which will address ecological; economic and social sustainability targets. The objectives should be consistent with the aims of the CFP, MSFD and other EU directives, but they should also be understandable by the wider stakeholder community and engage their support. This will then lead to the proposal of a number of potential management measures, based on existing or new approaches. The second step will be to analyze the incentives for compliance provided by these measures. In particular, we will examine fisher's responses and perceptions of these measures, based on historical analysis as well as direct consultation and interviews. This project part will also examine how the governance can be changed to facilitate self- and co-management to ensure fisher buy-in to promising management measures. In particular, the project will focus on the interpretation of overarching (i.e. EU) objectives in local and regional contexts. Finally, the project will examine the impacts of the management measures that emerge from this process, particularly in terms of their economic and social impacts. The IA analysis will be integrated by evaluating the proposed measures against the criteria of effectiveness, efficiency and coherence. Special attention will be paid in evaluating the proposed management measures' performance in terms of their ability to achieve the general and specific ecological objectives.
Das Projekt "Watershed sediment yield modelling for data scarce areas; a case study, Awash River Basin, Ethiopia" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasserbau durchgeführt. The main goal of the research was to device an alternative solution for watershed sediment yield modelling for data scarce areas where the existing physically based models can not be applicable. Awash River Basin in Ethiopia was selected as case study area. GIS data on soil, land use, precipitation, temperature, stream flow and suspended sediment yield was collected from the Federal Ministry of Water Resources of Ethiopia (FMWRE) and from the National Metrology Service Agency (NMSA) offices. Soil data obtained from FMWRE and Food and Agriculture Organization (FAO) world soil 1974 database was used for derivation of the soil erodibility factor (ERFAC) estimation equation. The ratio of silt to sand and clay content was considered as the governing factor for soil erodibility in developing the ERFAC equation. The SWAT2005 model was selected for calibration and validation of stream flow and sediment yield. A sensitivity analysis was carried out to prioritize model calibration parameters. From the sensitivity analysis, curve number II (CN2), soilwater available to plants (SOL-AWC) and ground water base flow factor (ALPHA-BF) were selected as major stream flow calibration parameters. Similarly CN2, SURLAG (surface lag), slope and sediment routing factor (SPCON) were taken as the major sediment calibration parameters. Parameters related to the soil properties and river channel characteristics were given special attention during the model calibration. Eleven years (1990-2000) stream flow and sediment data were used for model calibration and six years data (2001-2006) were used for model validation. Calibration has been done at three gauging stations located in the Awash River basin. The statistical indicators, Coefficient of determination (R2), Nash-Sutclife efficiency (NSE), Root mean square error observations standard deviation (RSR were applied to evaluate the calibration and validation results. The values of these indicators were used to ratethe performance of the model. Watershed geomorphologic and topographic factors were extracted from the SWAT2005 watershed configuration, using a GIS tool and empirical equations. The relative importance of the factors was determined using Pearsons correlation coefficient based on the sediment yield output obtained from the SWAT2005 model calibration. The results show that, the sediment yield is highly correlated with stream flow, watershed area and watershed slope. Based on the identified parameters and the SWAT2005 model output, an alternative sediment yield estimation equation was derived and checked for its validity.
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