Das Projekt "Co-estimation of the Earth main magnetic field and the ionospheric variation field" wird vom Umweltbundesamt gefördert und von Universität Potsdam, Institut für Mathematik durchgeführt. The aim of this project is to co-estimate models of the core and ionosphere magnetic fields, with the longer-term view of building a 'comprehensive' model of the Earths magnetic field. In this first step we would like to take advantage of the progresses made in the understanding of the ionosphere by global M-I-T modelling to better separate the core and ionospheric signals in satellite data. The magnetic signal generated in the ionosphere is particularly difficult to handle because satellite data provide only information on a very narrow local time window at a time. To get around this difficulty, we would like to apply a technique derived from assimilation methods and that has been already successfully applied in outer-core flow studies. The technique relies on a theoretical model of the ionosphere such as the Upper Atmosphere Model (UAM), where statistics on the deviations from a simple background model are estimated. The derived statistics provided in a covariance matrix format can then be use directly in the magnetic data inversion process to obtain the expected core and ionospheric models. We plan to apply the technique on the German CHAMP satellite data selected for magnetically quiet times. As an output we should obtain a model of the ionospheric magnetic variation field tailored for the selected data and a core-lithosphere field model where possible leakage from ionospheric signals are avoided or at least reduced. The technique can in theory be easily extended to handle the large-scale field generated in the magnetosphere.
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.
Das Projekt "Carbon, water and nutrient dynamics in vascular plant- vs. Sphagnum-dominated bog ecosystems in southern Patagonia" wird vom Umweltbundesamt gefördert und von Universität Münster, Mathematisch-Naturwissenschaftliche Fakultät, Fachbereich 14 - Geowissenschaften durchgeführt. In bog ecosystems, vegetation controls key processes such as the retention of carbon, water and nutrients. In northern hemispherical bogs, a shift from Sphagnum- to vascular plant-dominated vegetation is often traced back to Climate Change and increased anthropogenic nitrogen deposition and coincides with substantially reduced capacities in carbon, water and nutrient retention. In southern Patagonia, bogs dominated by Sphagnum and vascular plants coexist since millennia under similar environmental settings. Thus, South Patagonian bogs may serve as ideal examples for the long-term effect of vascular plant invasion on carbon, water and nutrient balances of bog ecosystems. The contemporary balances of carbon and water of both a bog dominated by Sphagnum and vascular plants are determined by CO2- H2O and CH4 flux measurements and an estimation of lateral water losses as well as losses via dissolved organic and inorganic carbon compounds. The high time resolution of simultaneous eddy covariance measurements of CO2 and H2O in both bog types and the strong interaction between climatic variables and the physiology of bog plants allow for direct comparisons of carbon and water fluxes during cold, warm, dry, wet, cloudy or sunny periods. By the combination with leaf-scale measurements of gas exchange and fluorescence, plant-physiological controls of photosynthesis and transpiration can be identified. Long-term peat accumulation rates will be determined by carbon density and age-depth profiles including a characterization of peat humification characteristics. A reciprocal transplantation experiment with incorporated shading, liming and labeled N addition treatments is conducted to explore driving factors affecting competition between Sphagnum and vascular plants as well as the interactions between CO2-, CH4-, and water fluxes and decisive plant functional traits affecting key processes for carbon sequestration and nutrient cycling. Decomposition rates and driving below ground processes are analyzed with a litter bag field experiment and an incubation experiment in the laboratory.
Das Projekt "COST Action TU0702 Real-time monitoring, surveillance and control of road networks under adverse weather conditions" wird vom Umweltbundesamt gefördert und von Hochschule Biberach, Institut für Immobilienökonomie, Infrastrukturplanung und Projektmanagement (IIP) durchgeführt. The main objective of the Action is to understand better the impacts of weather on freeways/motorways as well as on urban networks highway operations and to develop, promote and implement strategies and tools to mitigate those impacts. Adverse weather conditions can have a significant impact on traffic operations and quality of traffic flow. The advanced technologies for collecting and archiving weather data can assist the development of intelligent weather-based traffic management strategies, monitoring and control systems. In view of the paramount importance of weather-responsive tools for real-time traffic surveillance, this project will focus on the development of strategies and techniques aimed at improving the road traffic management and safety. The main goal is to mitigate the negative impacts of adverse weather conditions to traffic flows and to predict the traffic flows under adverse weather conditions. The term of 'adverse weather conditions refers to the meteorological conditions that decrease the visibility and worsen the pavement conditions. This project will bring together researchers actively working on road networks related issues. It will concentrate on mutually complementary methodologies for modelling, estimation and control that will improve the safety of traffic networks. Traffic flows are highly dependent on weather conditions and researches on this issue are very limited in the literature. Next, traffic flow prediction by reliable algorithms will be addressed in tight connection with the traffic sensor network. This project will address also many issues related to efficient, reliable and quick exchange of information and data over sensor networks for vehicular traffic. The data are received only at boundaries between some segments and averaged within possibly irregular time intervals. Additionally, there are missing data and sensor failures that need to be taken into account. Further, with the developed models and estimators, advanced control strategies will be developed dealing with appropriate fusion of the multiple sensor data.
Das Projekt "Root distribution and dynamics and their contribution to subsoil C-fluxes" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abteilung Pflanzenökologie und Ökosystemforschung durchgeführt. It has been suggested that dying and decaying fine roots and root exudation represent important, if not the most important, sources of soil organic carbon (SOC) in forest soils. This may be especially true for deep-reaching roots in the subsoil, but precise data to prove this assumption are lacking. This subproject (1) examines the distribution and abundance of fine roots (greater than 2 mm diameter) and coarse roots (greater than 2 mm) in the subsoil to 240 cm depth of the three subsoil observatories in a mature European beech (Fagus sylvatica) stand, (2) quantifies the turnover of beech fine roots by direct observation (mini-rhizotron approach), (3) measures the decomposition of dead fine root mass in different soil depths, and (4) quantifies root exudation and the N-uptake potential with novel techniques under in situ conditions with the aim (i) to quantify the C flux to the SOC pool upon root death in the subsoil, (ii) to obtain a quantitative estimate of root exudation in the subsoil, and (iii) to assess the uptake activity of fine roots in the subsoil as compared to roots in the topsoil. Key methods applied are (a) the microscopic distinction between live and dead fine root mass, (b) the estimation of fine and coarse root age by the 14C bomb approach and annual ring counting in roots, (c) the direct observation of the formation and disappearance of fine roots in rhizotron tubes by sequential root imaging (CI-600 system, CID) and the calculation of root turnover, (d) the measurement of root litter decomposition using litter bags under field and controlled laboratory conditions, (e) the estimation of root N-uptake capacity by exposing intact fine roots to 15NH4+ and 15NO3- solutions, and (f) the measurement of root exudation by exposing intact fine root branches to trap solutions in cuvettes in the field and analysing for carbohydrates and amino acids by HPLC and Py-FIMS (cooperation with Prof. A. Fischer, University of Trier). The obtained data will be analysed for differences in root abundance and activity between subsoil (100-200 cm) and topsoil (0-20 cm) and will be related to soil chemical and soil biological data collected by the partner projects that may control root turnover and exudation in the subsoil. In a supplementary study, fine root biomass distribution and root turnover will also be studied at the four additional beech sites for examining root-borne C fluxes in the subsoil of beech forests under contrasting soil conditions of different geological substrates (Triassic limestone and sandstone, Quaternary sand and loess deposits).
Das Projekt "Multiple-site seismic hazard assessment" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Geophysikalisches Institut durchgeführt. The classical point wise Cornell-McGuire probabilistic seismic hazard assessment (PSHA), which is widely used for seismic hazard mapping and development of design codes, does not allow direct estimation of multiple-location hazard for distributed structures and facilities: what is the (annual) probability that specific level of ground motion will be exceeded simultaneously in several sites? It is possible to extent the classical methodology to the multiple sites problem considering also ground-motion correlation. We study multiple-location PSHA, as compared with the classical point wise PSHA, using Monte Carlo simulation. Specific items are:(1) Development of the algorithms for multiple-location PSHA;(2) Analysis of the role of the geometry of multiple sites, correlation of ground motion, and evel of seimicity for multiple-location PSHA;(3) Study of correspondence and differences between multiple-location PSHA and classical point wise PSHA and analysis of possibility of utilization of classical PSHA procedures for simplified multiple-location hazard assessment.The project is innovative because only few attempts have been made so far regarding our research questions.
Das Projekt "Development of an integrated forest carbon monitoring system with field sampling and remote sensing for tropical forests in Indonesia" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Burckhardt-Institut, Abteilung Waldinventur und Fernerkundung durchgeführt. Forests play a relevant role in mitigation of climate change. A major issue, however, is the scientifically well founded, transparent and verifyable monitoring of achievements in forest carbon sequestration through reduction of deforestation and forest degradation, and through fostering sustainable forest management. Monitoring is particularly difficult in diverse and inaccessible humid tropical forest areas. The proposed research will contribute to the improvement of forest carbon monitoring under the challenging conditions of humid tropical forests. Sample based field observations and model based biomass predictions will be linked to area-wide satellite remote sensing imagery (RapidEye) and to strip samples of LiDAR imagery. Techniques of linking these data sources will be further developed and analysed with respect to (1) precision of carbon estimation and (2) accuracy of carbon regionalization. The proposed project implies research on methodological improvements of both sample based forest inventories (resampling techniques for biomass, imputation of non-response) and remote sensing application to forest monitoring (regionalization, sample based application of LiDAR data). At the core of this research is the analysis of the error variance components that each data source brings into the system. Such error analysis will allow identifying optimal resource allocation for the efficient improvement of forest carbon monitoring systems.
Das Projekt "Drivers and mechanisms of 13C discrimination in Cleistogenes squarrosa (C4) - reducing uncertainties on bundle sheath leakiness" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Lehrstuhl für Grünlandlehre durchgeführt. The energetic efficiency of C4 photosynthesis is strongly affected by bundle sheath leakiness, which is commonly assessed with the 'linear version' of the Farquhar model of 13C discrimination, and leaf gas exchange and 13C composition data. But, the linear Farquhar model is a simplification of the full mechanistic theory of ? in C4 plants, potentially generating errors in the estimation of leakiness. In particular, post-photosynthetic C isotope fractionation could cause large errors, but has not been studied in any detail. The present project aims to improve the understanding of the ecological and developmental/physiological factors controlling discrimination and leakiness of the perennial grass Cleistogenes squarrosa. C. squarrosa is the most important member of the C4 community which has spread significantly in the Mongolia grasslands in the last decades. It has an unusually high and variable discrimination, which suggests very high (and potentially highly variable) leakiness. Specifically, we will conduct the first systematic study of respiratory 13C fractionation in light and dark at leaf- and stand-scale in this C4 species, and assess its effect on discrimination and estimates of leakiness. These experiments are conducted in specialized 13CO2/12CO2 gas exchange mesocosms using ecologically relevant scenarios, testing specific hypotheses on effects of environmental drivers and plant and leaf developmental stage on discrimination and leakiness.
Das Projekt "Assessment of Effects of EU Aflatoxin Standards along Cereals Value Chain in Russia: German Methodological Proficiency Complemented by Russian Local Knowledge" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Landwirtschaftliche Betriebslehre durchgeführt. Globalization raised the importance of food safety and quality concerns. Developed countries implement precautionary food regulation policies to protect their affluent consumers from unsafe food imported from developing and transition countries. However, the alarming number of trade disputes at WTO evidences cases of abuse of such policies. While claims on protectionist nature of food regulations are valid in principle, yet there is little empirical evidence about their economic effects. The questions of 1) quantification of trade impact of food standards and 2) investigation of national food regulation systems are absolutely essential for the new trade agenda. These problems for developing countries are on the focus of trade policy debate, whereas for transition countries are not considered seriously. Such a research for these recently liberalized markets gains a special significance. - The proposed research will employ Gravity Model for quantitative estimation of impact of EU aflatoxin standards on transition countries- exports.- Russian food regulations for cereal value chain, their enforcement and monitoring mechanisms will be investigated through value chain and cost-benefit analysis.- Compliance of Russian norms with EU standards will be estimated applying comparative advantage analysis.The study area is Stavropol region of the Russian Federation. Local experts will contribute to the construction of the research data set and analysis. The results of the research will assist 1) international policy makers in designing new global trade agenda and 2) Russian producers, exporters and decision makers in improving cereal value chain.
Das Projekt "Effects of water content, input of roots and dissolved organic matter and spatial inaccessibility on C turnover & determination of the spatial variability of subsoil properties" wird vom Umweltbundesamt gefördert und von Universität Kassel, Lehr- und Forschungsgebiet Umwelt- und Lebensmittelwissenschaften, Fachgebiet Umweltchemie durchgeführt. It is well established that reduced supply of fresh organic matter, interactions of organic matter with mineral phases and spatial inaccessibility affect C stocks in subsoils. However, quantitative information required for a better understanding of the contribution of each of the different processes to C sequestration in subsoils and for improvements of subsoil C models is scarce. The same is true for the main controlling factors of the decomposition rates of soil organic matter in subsoils. Moreover, information on spatial variabilities of different properties in the subsoil is rare. The few studies available which couple near and middle infrared spectroscopy (NIRS/MIRS) with geostatistical approaches indicate a potential for the creation of spatial maps which may show hot spots with increased biological activities in the soil profile and their effects on the distribution of C contents. Objectives are (i) to determine the mean residence time of subsoil C in different fractions by applying fractionation procedures in combination with 14C measurements; (ii) to study the effects of water content, input of 13C-labelled roots and dissolved organic matter and spatial inaccessibility on C turnover in an automatic microcosm system; (iii) to determine general soil properties and soil biological and chemical characteristics using NIRS and MIRS, and (iv) to extrapolate the measured and estimated soil properties to the vertical profiles by using different spatial interpolation techniques. For the NIRS/MIRS applications, sample pretreatment (air-dried vs. freeze-dried samples) and calibration procedures (a modified partial least square (MPLS) approach vs. a genetic algorithm coupled with MPLS or PLS) will be optimized. We hypothesize that the combined application of chemical fractionation in combination with 14C measurements and the results of the incubation experiments will give the pool sizes of passive, intermediate, labile and very labile C and N and the mean residence times of labile and very labile C and N. These results will make it possible to initialize the new quantitative model to be developed by subproject PC. Additionally, we hypothesize that the sample pretreatment 'freeze-drying' will be more useful for the estimation of soil biological characteristics than air-drying. The GA-MPLS and GA-PLS approaches are expected to give better estimates of the soil characteristics than the MPLS and PLS approaches. The spatial maps for the different subsoil characteristics in combination with the spatial maps of temperature and water contents will presumably enable us to explain the spatial heterogeneity of C contents.
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