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Found 63 results.

A meta-analysis of global insecticide concentrations in agricultural surface waters

Although global pesticide use increases steadily, our field-data based knowledge regarding exposure of non-target ecosystems is very restricted. Consequently, this meta-analysis will for the first time evaluate the worldwide available peer-reviewed information on agricultural insecticide concentrations in surface water or sediment and test the following two hypotheses: I) Insecticide concentrations in the field largely exceed regulatory threshold levels and II) Additional factors important for threshold level exceedances can be quantified using retrospective meta-analysis. A feasibility study using a restricted dataset (n = 377) suggested the significance of the expected results, i.e. an threshold level exceedance rate of more than 50Prozent of the detected concentrations. Subsequent to a comprehensive database search in the peer-reviewed literature of the past 60 years, analysis of covariance with the relevant threshold level exceedance as the continuous dependent variable (about 10,000 cases) will be performed and the impact of significant predictor variables will be quantified. Parameters not yet considered in pesticide exposure assessment will be included as independent variables, such as compound class, environmental regulatory quality, and sampling design. The simultaneous presence of several insecticide compounds as a well as their metabolites will also be considered in the evaluation. The present approach may provide an innovative and integrated view on the potential environmental side effects of global high-intensity agriculture and in particular of pesticides use.

Linking internal pattern dynamics and integral responses - Identification of dominant controls with a strategic sampling design

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.

The parent material as major factor for the properties of the biogeochemical interface: Integrative analysis

The formation of biogeochemical interfaces in soils is controlled, among other factors, by the type of particle surfaces present and the assemblage of organic matter and mineral particles. Therefore, the formation and maturation of interfaces is studied with artificial soils which are produced in long-term biogeochemical laboratory incubation experiments (3, 6, 12, 18 months. Clay minerals, iron oxides and charcoal are used as major model components controlling the formation of interfaces because they exhibit high surface area and microporosity. Soil interface characteristics have been analyzed by several groups involved in the priority program for formation of organo-mineral interfaces, sorptive and thermal interface properties, microbial community structure and function. Already after 6 months of incubation, the artificial soils exhibited different properties in relation to their composition. A unique dataset evolves on the development and the dynamics of interfaces in soil in the different projects contributing to this experiment. An integrated analysis based on a conceptual model and multivariate statistics will help to understand overall processes leading to the biogeochemical properties of interfaces in soil, that are the basis for their functions in ecosystems. Therefore, we propose to establish an integrative project for the evaluation of data obtained and for publication of synergistic work, which will bring the results to a higher level of understanding.

Geosuche

Die Geosuche ist ein Webservice, welcher über die EGovernment-Basiskomponente Geodaten (GeoBAK) bereitgestellt wird. Die Geosuche ermöglicht eine multikriterielle Recherche nach ausgewählten Geobasisdaten und Geofachdaten, Geoinformationen (Metadaten) sowie Portalinhalten (Webseiten, Dokumente). Sie ist zentraler Bestandteil des Geoportals Sachsenatlas und als Freie Suche bzw. Volltextsuche ausgelegt. Die Umsetzung der Suche im Geoportal als singuläres Suchfeld (Omnibox, Einfeldsuche) analog zu bekannten Internetsuchmaschinen, ermöglicht einen schnellen Einstieg der Nutzer. Die Geosuche ermöglicht im Gegensatz zu standardisierten OGC-Geodatendiensten wie z.B. OGC-WFS-Gazetteer eine performanceoptimierte Recherche, welche nicht nur auf Geodaten beschränkt ist. Die Geosuche ermöglicht aufgrund der Filter- und Sortiermöglichkeiten die Umsetzung von über die Einfeldsuche hinausgehenden Recherchemöglichkeiten. Im Geoportal ist dies über die erweiterte Suche mit z.B. räumlicher und zeitlicher Auswahlmöglichkeit umgesetzt. Weiterhin sind einzelne Objekte untereinander verknüpft. Damit ist beispielsweise die Recherche nach allen Hausnummern einer Straße möglich (Drilldown). Die Umsetzung von Formularen mit Auswahllisten für eine Recherche, die die Geosuche aufrufen, ist möglich.

HGF-Allianz: Remote Sensing and Earth System Dynamics (HGF-REMOTE)

The HGF Alliance 'Remote Sensing and Earth System Dynamics' aims at the development and evaluation of novel bio/geo-physical information products derived from data acquired by a new generation of remote sensing satellites; and their integration in Earth system models for improving understanding and modelling ability of global environmental processes and ecosystem change. The Earth system comprises a multitude of processes that are intimately meshed through complex interactions. In times of accelerated global change, the understanding and quantification of these processes is of primary importance. Spaceborne remote sensing sensors are predestined to produce bio-geo-information products on a global scale. The upcoming generation of spaceborne remote sensing configurations will be able to provide global data sets and products with unprecedented spatial and temporal resolution in the context of a consistent and systematic observation strategy. The integration of these data sets in existing environmental and climate science components will allow a new global view of the Earth system and its dynamics, initiating a performance leap in ecosystem and climate change modelling.

Rock boulders as indicators of soil erosion (RAISE)

Landscape and soil changes are strongly coupled to chemical and physical (erosion) weathering and soil production. The erosion rate is preserved in the signal of cosmogenic nuclides (e.g., 10Be) in stream sediments or even directly in a soil profile. The genesis of clastic sediments and soils has been investigated to quantify processes occurring within source areas and catchments, including chemical and physical weathering, and textural and compositional modification of detritus during transition from bedrock to grus and thereafter to soil or a fluvial environment. Well-defined (or -controlled) settings are however needed to calculate mass balances for a given (tectonically active) catchment. Measurements of mid- to long-term erosion rates have recently become more widely available through cosmogenic nuclide techniques. Still, new approaches can be developed to improve our understanding of weathering processes and their rates. Ideal settings and a considerable dataset about mineral weathering are given for the Sila massif in southern Italy (and consequently in a Mediterranean environment). It represents a tectonically active area. The upland plateaus consist of old planation surfaces, bordered by steep slopes, and are characterised by granitic spheroidal boulders which form wide boulder fields. The combination of the major tectonic and relief features with typical upland Mediterranean climate conditions promoted the triggering of severe erosion, that led to the exhumation of the boulders. Data about soil erosion amounts and rates related to the soil formation period would complete the puzzle of the driving forces and enable a more detailed interpretation of landscape and soil evolution. These boulders seemed to 'grow' out of the surface with time. Consequently, by measuring the 10Be content at different levels along a rock boulder (from the soil surface to the top of boulders), the age(s) of exposure could be derived and subsequent total denudation rates will be obtained. This would be an elegant way to calculate erosion rates for different time-steps that cover almost the entire period of soil evolution. Such an approach would give insight into a) the overall denudation and erosion rates over the whole (potential) soil formation period and b) erosion and denudation rates during time segments and would allow for the distinction of different erosion phases during the Pleistocene and Holocene c) volumes of loose material that were removed from the uplands and entered the drainage river system in this time span. (...)

Schwerpunktprogramm (SPP) 1167: Quantitative Niederschlagsvorhersage, The verification of precipitation forecasts from numerical models on short time-scales over Germany with pattern-oriented error measures

The verification of precipitation forecasts from numerical models is essential for the future improvement of quantitative precipitation forecasts (QPF). There are various options when defining a QPF verification strategy, concerning for instance the temporal resolution, the choice of the evaluation data set, the verification domains, the weather-type stratification and the applied error measures. In this project new techniques will be developed to verify QPFs from the weather prediction models LM, GME and ECMWF over Germany on very short time scales (typically 1 hour). A currently developed technique is used to derive an evaluation data set of hourly precipitation analyses from rain-gouge measurements and radar composites. The verifications will be done for the catchment areas of the major river systems and the QPFs will be categorized into different synoptic weather patterns. Finally, new error measures will be implemented that consider the spatial patterns of precipitation, in contrast to more traditional measures that evaluate the similarity of two fields on a point-by-point basis. Such an pattern-oriented approach provides novel and meaningful information about the qualities and deficiencies of a particular QPF. The results will be directly useful for the interpretation of model output in operational weather forecasting and for their quantitative use in impact applications such as runoff forecasting.

Assessment of Effects of EU Aflatoxin Standards along Cereals Value Chain in Russia: German Methodological Proficiency Complemented by Russian Local Knowledge

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.

Support to Science Element Water Cycle Multimission Observation Strategy

The primary objectives of the WACMOS project are to identify, develop, and validateimproved multi-mission based methods to obtain a robust data set of prototypeproducts at global/regional (over in particular land, but not excluding ocean and otherwater bodies) and basin scales, including evapotranspiration, soil moisture, clouds andwater vapour. The project will also facilitate the integration of the above products intoboth models and data assimilation processes at different scales, including productcross-comparison and error characterization (e.g., run-off, water balance, flood risk,drought, climate) and will consolidate the user base (scientific and institutional) andestablish a potential scientific roadmap to advance the establishment of long-termrobust multi-source data records of the required variables.

Monitoring of Water Content Distributions inside a Lysimeter with GPR-Tomography

A lysimeter is a vessel containing soil placed with its top edge to the ground surface. Lysimeter are used to study phases of the hydrological cycle in terms of water content and dynamics, e.g. infiltration, evapotranspiration or runoff. Lysimeter provide a good alternative to carry out and test various methods or theoretical theories under relative undisturbed circumstances. In cooperation with the Institute of Chemistry and Dynamics of the Geosphere, IV Agrosphere (ICG-IV) of the Forschungszentrum Jülich GmbH, the solute transport inside a lysimeter ought to be investigated.To avoid the inevitable problem of the boundary conditions for electromagnetic geophysical methods of a normal lysimeter with its metal wall, an alternative had to be found. Therefore PVC-cylinders were chosen with 1.5 m height and 1.2 m diameter. The dielectric permittivity of soils depends strongly on the water content. Therefore, GPR was used as it can provide non-invasive high-resolution information regarding the distribution of the dielectric permittivity of a heterogeneous medium. Because the used lysimeter has PVC walls tomographic measurements can be performed. Considering the relatively small dimensions of the lysimeter (1.2m diameter, 1.5m height) and the armament with sensors for other methods, a pair of shielded antennas was chosen with centre frequencies of approx. 750 MHz. In April and September 2002 first measurements were carried out on a filled but unequipped lysimeter to check signal quality, feasibility as well as the needed time to gather a dataset under ideal conditions. Furthermore pot irrigation tests were made in 2002 and 2004 to estimate the actual resolution with the available equipment. To derive the volumetric water content, the calculated dielectric permittivity values have to be transformed. Based on the soil inside the lysimeter (approx. 80% sand, 15% silt and 5% clay with approx. 40% porosity) appropriate mixing formulas for bulk dielectric permittivity have to be chosen and compared to the results gathered from alternative methods.

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