Das Projekt "The role of sympagic meiofauna for the flow of organic matter and energy in the Antarctic and Arctic sea-ice foodwebs" wird vom Umweltbundesamt gefördert und von Universität Kiel, Institut für Polarökologie durchgeführt. The brine channels in sea ice (Fig. 1) of both polar regions are the habitat of sympagic (ice-associated) bacteria, algae, protozoans and small metazoans greater than 20 mym (meiofauna, Fig. 2), including copepods, plathyelminthes, rotifers, nematodes, cnidarians, nudibranchs and ctenophores. Primary production of sympagic algae forms the basis of the sea-ice food web, which is coupled to the pelagic ecosystem and higher trophic levels. The overall objective of this project is to reveal the qualitative and quantitative role of sympagic meiofauna for the flow of organic matter and energy in the Antarctic and Arctic sea-ice foodwebs. The major focus is on sympagic meiofauna because this group could, due to in part very high abundances, play an important role within the sea-ice ecosystem. Moreover, since sympagic metazoans are a food source for higher trophic levels (e.g. larger zooplankton, fish), they probably occupy a key position in coupling processes between the sea ice and pelagic ecosystems. Sympagic meiofauna can thus be supposed to significantly contribute to the flow of organic matter and energy in polar marine food webs. In spite of this, little information on the feeding ecology of this group is available as yet.
Das Projekt "A6: Response of element cycles in a tropical mountain rain forest to environmental and land-use change" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Institut für Geographie und Geoökologie durchgeführt. The north Andean forest is affected by climate-driven acid and base depositions and will experience increasing N input in the future. Based on our knowledge of element cycling in the Reserva Biologica San Francisco, we aim at developing scenarios of possible responses of the study forest to expected environmental change. We will evaluate the available data series and complete the parameterization of a catchment-based hydrologic model (CATFLOW). We will assume the joint change scenarios of the Research Unit. The developed scenarios will be validated by continuing the Long-term Ecosystem Study and the Nutrient Management Experiment (NUMEX). The Long-term Ecosystem Study was established in 1998. For greater than 11 years, a unique data set of weekly records of all major water and element fluxes has been collected. In the interdisciplinary NUMEX experiment, established in 2007, we continuously add N, P, N+P, and Ca twice per year to native forest in a block design at ca. 2000 m a.s.l. to explore the forest response to low-level nutrient input. For the next phase, a joint 15N pulse chasing experiment will be conducted to further explore the fate of added N. We contribute by setting up a complete flux budget of the applied isotope label.
Das Projekt "B 2.3: Transport of agrochemicals in a watershed in Northern Thailand - Phase 3" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre, Fachgebiet Biogeophysik durchgeführt. Land use changes of the last decades in the mountainous regions of Northern Thailand have been accompanied by an increased input of agrochemicals, which might be transferred to rivers by surface and/or subsurface flow. Where the river water is used for household consumption, irrigation and other purposes, agrochemical losses pose a serious risk to the environment and food safety. In the first and the second phase, subproject B2 collected data on and gained knowledge of the vertical and lateral transport processes that govern the environmental fate of selected agrochemicals at the plot and the hillslope scale (Ciglasch et al., 2005; Kahl et al., 2006). In the third phase, B2.3 will turn from the hillslope to the watershed scale. For simulation of water flow and pesticide transport the SWAT model (Neitsch et al., 2002b) will be adapted and used. The study area will be the Mae Sa watershed (138 km2), which includes the Mae Sa Noi subcatchment where B2 carried out detailed investigations during the last two phases. The specific focus of the subproject will be the parameterization and calibration of the SWAT model and its integration into the model network of the SFB. The SFB database has been established and can be used for model parameterization. In addition, high-quality geo-data are available from the Geoinformatic and Space Technology Development Agency (GISTDA) in Chiang Mai. For model calibration, discharge measurements are available for the Mae Sa Noi subcatchment (12 km2) and for the neighboring Mae Nai subcatchment (18 km2). To collect data on the Mae Sa watershed discharge, at the very beginning of the third phase gauging stations will be established in a midstream position and at the outlet of the watershed. Pesticide fluxes will be measured at each gauging station as well as in the Mae Sa Noi subcatchment, where B2.2 has operated two flumes equipped with automatic discharge-proportional water samplers since 2004. Rainfall distribution and intensity will be monitored with a net of automatic rain gauges. Hydrograph separation will be performed using soil and river temperatures (Kobayashi et al., 1999). Within the watershed temperature loggers will be installed at different soil depths to measure the temperature of the different discharge components. Already at the beginning of the second year of the third phase we will start to couple the SWAT model with land use and farm household models of the SFB and to use the model to assess the effect of land use and land management changes on the loss of pesticides to surface waters.
Das Projekt "Sub-project 2" wird vom Umweltbundesamt gefördert und von Herzberger Wasser- und Abwasserzweckverband KdöR durchgeführt. Ziel ist die Entwicklung der entscheidungsunterstützenden Toolbox DEMAPLAN - DEmand-oriented MANagment und PLANning -, die Wasserversorgern und Planungs- und Ingenieurbüros zwei Software-Tools für eine effiziente Planung und Bewirtschaftung von Wasserinfrastruktursystemen bereitstellen soll. Die erste Software DEMAPLANstrat ist ein Prognosemodell für effiziente Planungsentscheidungen. Die zweite Software DEMAPLANopera ist ein Analyse- und Auswertungsinstrument, um ein Verbrauchsmanagement für eine effiziente Bewirtschaftung der Netze und Anlagen aufzubauen. Im ersten Schritt wird ein Leistungskatalog, eine Systemarchitektur und ein webfähiges Anwendungskonzept für die Toolbox DEMAPLAN entwickelt. Im Anschluss erfolgt die konzeptionelle Entwicklung der Tools. Für DEMAPLANstrat werden basierend auf Haushaltsumfragedaten und externen Daten ökonometrische Modelle zur Haushaltswassernachfrage für Siedlungsstrukturtypen entwickelt. Für DEMAPLANopera werden auf der Haushaltsebene hochauflösende Wassergebrauchsanalysen nach dem innovativen Konzept der Flow Trace Analysis durchgeführt, eine Analyse- und Auswertungssystematik, Wassergebrauchsprofile für einzelne Wassernutzungstechnologien in Haushalten und ein End-use Modell entwickelt. Im dritten Schritt erfolgt die Überführung der Entwicklungskonzepte und der Forschungsarbeiten in eine EDV-gestützte Anwendersoftware. Der gesamte Prozess der Softwareentwicklung wird von einem Expertenkreis aus der Wasserwirtschaft begleitet.
Das Projekt "Land Cover Change Assessment in Catchments of the Lower Mekong Basin" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Burckhardt-Institut, Abteilung Waldinventur und Fernerkundung durchgeführt. Since 1950, the riparian countries of the Mekong River have undergone a dynamic change in land-use. Extensive areas of forest have been logged and cleared for agriculture. Hamilton (1987) emphasizes the role of scale in measuring the impacts of land-use practices. They can be classified into three categories based on the affected area: local level, medium level and macro level. Impacts occur at the local scale in the area where land-use takes place, caused e.g. by soil erosion, new fallow zones or areas showing declines in soil fertility and productivity. Impacts at the medium or macro scale are e.g. sedimentation and siltation of riverbeds, reservoirs and irrigation systems, frequency of low flows and floods, deposition of chemical residues in rivers and lakes. These last-mentioned impacts are more difficult and complex to manage. There are only few empirical studies on the relationship between the removal of forest and land-use changes regarding water yield (low flows, floods), soil erosion, sedimentation and nutrient load of streams within the geographical context of the Lower Mekong Basin. Quantitative information is needed to support decisions in watershed management which includes management of all natural resources within a watershed for the protection and production of water resources while maintaining environmental stability. Objectives: In the framework of two master theses a time series of land cover changes from the 1950s to 2000 will be processed and analysed for the Nam Ton Pilot catchment in Laos PDR using remote sensing and GIS. The following materials are available at MRCS: Landsat TM and ETM+ images, SPOT images, aerial photos: 1:20,000 and 1:50,000 scale
Das Projekt "Sub project: Mass transfer, aging and reactions at NAPL interfaces in porous media" wird vom Umweltbundesamt gefördert und von Universität Tübingen, Zentrum für Angewandte Geowissenschaften - Umweltmineralogie und Umweltchemie durchgeführt. Release of non-aqueous phase liquids (NAPLs) into natural porous media is a widespread environmental problem. Transfer of pollutants across the NAPL-water phase boundary determines both the extent of groundwater contamination as well as the persistence of residual NAPL phases in porous media. Previous research has shown that NAPL-water interfaces are subject to 'aging' phenomena in aqueous environments, e.g., development of skin-like viscous films. However, surprisingly litte is known about the factors and mechanisms that control such film formation of NAPLs in aqueous porous media and about the effects of such films on mass transfer of organic contaminants from the NAPL to the aqueus phase. In the proposed project we will address these knowledge gaps in order to (i) achieve a process based understanding of reactions and environmental conditions leading to the formation of viscous phase boundaries of NAPLs in porous media (aging) and to (ii) develop and vali-date a physical model of such boundary layers to quantify time-dependent interfacial phenomena in multi-component NAPL-water systems (mass transfer). To this end we will carry out batch and flow-through experiments with model and real NAPLs in water and aqueous porous media and make intense use of chemical probe techniques. We will utilize chemical and rheological analysis, microscopic process modeling and, in cooperation with partners within the research group, we will apply new designs of spectroscopic and electrochemical tools for spatially highly resolved investigations of the interface as well as contribute to reactive transport modeling at NAPL-contaminated porous media.
Das Projekt "Upscale Error Growth - A2: Structure formation on cloud scale and impact on larger scales" wird vom Umweltbundesamt gefördert und von Johannes Gutenberg-Universität Mainz, Institut für Physik der Atmosphäre durchgeführt. Cloud particles are determined by microscopic processes, such as nucleation/condensation, growth, aggregation and sedimentation. These processes can feedback on dynamics or organize themselves and form macroscopic cloud structures on the order of tens of kilometers. At particles scales (order of micrometers) only little energy is transferred in the system. However through forming structures on cloud scales, diabatic heat sources are confined and concentrated on this scale and can interact with atmospheric flows. In this project the formation of cloud structures and structures in clouds will be investigated. We will identify and determine possible structures in clouds containing ice crystals, i.e., mixed-phase clouds and pure ice clouds. In addition, we will identify the governing processes leading to structure formation and investigate the impact of cloud structures on processes on larger scales than cloud scale. Our approach is two-fold, using high-resolution modeling of clouds and mathematical analysis of cloud physics equations. For consistency, we start with a common analytical cloud model, which will be used in both parts of the project. In the modeling part of the project we will carry out high-resolution numerical simulation of clouds, represented by the cloud model coupled to equations of atmospheric motion (sound-proof models of compressible viscous flows). We will concentrate on convective situations, starting with moist Rayleigh-Benard convection, extended to multiphase systems, but proceed to more realistic convective scenarios. The output of the simulations will be evaluated in terms of temporal and/or spatial structures of clouds. Complementary, we will investigate the underlying equation of cloud physics combined with atmospheric dynamics using mathematical analysis. We will use different methods in order to identify possible structure formation. For direct analysis we will use techniques from dynamical system theory in order to analyze the equations in terms of equilibrium states, limit cycles, Lyapunov exponents, bifurcations due to parameters and attractors, respectively. On the other hand, we will use reduction techniques (e.g., as used for Landau-Ginzburg equations or reduced order methods) in order to simplify the underlying equations towards the governing processes determining structure formation. In a synthesis of these methods (structures in numerical modeling vs. mathematical analysis) we will finally derive some minimal models describing structure formation on cloud scale. These models will allow us to determine the impact of cloud scale structures on larger scales. Finally, we will carry out first numerical investigations on the impact of structured heat sources on atmospheric flows. Here, minimal models as derived during the project will be used for describing the structured heat sources, embedded into an atmospheric flow for certain idealized flow conditions. (abridged text).
Das Projekt "Phosphorus transport along soil pathways in forested catchments" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Institut für Bodenkunde und Standortslehre durchgeführt. Phosphorus (P) is an essential nutrient for living organisms. Whereas agriculture avoids P-limitation of primary production through continuous application of P fertilizers, forest ecosystems have developed highly efficient strategies to adapt to low P supply. A main hypothesis of the SPP 1685 is that P depletion of soils drives forest ecosystems from P acquiring system (efficient mobilization of P from the mineral phase) to P recycling systems (highly efficient cycling of P). Regarding P fluxes in soils and from soil to streamwater, this leads to the assumption that recycling systems may have developed strategies to minimize P losses. Further, not only the quantity but also the chemistry (P forms) of transported or accumulated P will differ between the ecosystems. In our project, we will therefore experimentally test the relevance of the two contrasting hypothetical nutritional strategies for P transport processes through the soil and into streamwater. As transport processes will occur especially during heavy rainfall events, when preferential flow pathways (PFPs) are connected, we will focus on identifying those subsurface transport paths. The chemical P fractionation in PFPs will be analyzed to draw conclusions on P accumulation and transport mechanism in soils differing in their availability of mineral bound P (SPP core sites). The second approach is an intensive streamwater monitoring to detect P losses from soil to water. The understanding of P transport processes and P fluxes at small catchment scale is fundamental for estimating the P exports of forest soils into streams. With a hydrological model we will simulate soil water fluxes and estimate P export fluxes for the different ecosystems based on these simulations.
Das Projekt "Sub project: Evolution of highly explosive Nemrut and Süphan volcanoes (NE Anatolia) and Lake Van basin during the past 500.000 years" wird vom Umweltbundesamt gefördert und von Universität Kiel, GEOMAR Forschungszentrum für marine Geowissenschaften durchgeführt. The overall objective is a temporal, geodynamic and environmental reconstruction of a tectonically and volcanically highly active, volcano-bordered, closed lake basin. Coupling of the systems active volcanoes Nemrut and Süphan - alkaline Lake Van (Anatolia) over the past c. 500 ka will be studied by analyzing deposits of large explosive eruptions on land and via available short cores in preparation for a lake drilling project (2010). Tephra of widespread major explosive volcanic events from both volcanoes (fallout and flow deposits) will be analyzed in the field and laboratory by structural, textural, compositional and physical age determinations (XRF, EMP, laser-ICP-MS of glass and phenocrysts and 40Ar/39Ar single crystal dating). These data will allow determination of the magnitude of eruptions, their distribution in time and space, regional correlation and correlation with, and between, drill sites and mass flux into the lake through time. Major goals include short and long-term climate impacts as reflected in paleosols separating major tephra units and paleowind directions. Temporal and dynamic reconstruction of volcanic mass transfer (Plinian fallout, pyroclastic flows, flank collapses and tsunamis resulting from sudden mass impact onto the lake) will help to assess hazard and risk for the populated areas bordering Lake Van, an area of rapid development in Turkey.
Das Projekt "Two blade propeller turbine suspended under a barge using kinetic energy of river flows" wird vom Umweltbundesamt gefördert und von Bodan-Werft Metallbau durchgeführt. Objective: To demonstrate how a two bladed propellor turbine suspended under a barge can exploit the kinetic energy of a river to produce electricity. General Information: The barge will be moored in the river and the kinetic energy of the river used to drive the propellor turbine, thus eliminating the need for expensive civil works. It is expected that the main application would be to supply local communities not connected to the national grid system, particularly in developing countries. A further advantage of the scheme is that, unlike conventional hydro systems, it can be very easily replicated. Initially a suction tube to concentrate water flow was envisaged, but this has now been omitted as it became apparent that it was only of advantage in very deep rivers. Suitable control mechanisms are being investigated to match the requirement for constant generator speed to variable river flow rates. Head 0 metres River velocity 2-3 m/second Turbine propellor (1. 44 metres diameter) Turbine power 40 kW Generator synchronous End-use isolated system Achievements: The apparatus proved very successful concerning manufacture, transport, sea-going quality (local velocity of current up to 4 m/s were tested). stability with propeller swung up. Propeller support with lifting device and foundations for gears and generator. The two-bladed propeller could cope well with stripping off driftage. The chain (L approx. 2,8 m) is extremely suitable for the transmission of the high torque and can be adapted to suit power output. Fluctuations during the turning moment probably caused by vibrations of the chain can be reduced by baffle rods. Presumably turbulences around the 'suction pipe' contribute to the fluctuations. These turbulences could possibly be avoided or at least reduced by the profiling of the 'suction pipe' on the descending current side. By means of the demonstration model it can be proved that, in principle, the system functions. In case of a series production the control system must be improved appropriately. The turning moments left of the optimum of the moment curves, plotted against the rotations per minute, could not be determined, as the propeller dragged in the optimum area and either came to a stand-still or operated right of the optimum. Operation costs were estimated at approx. 7,5 per cent of the investment expenses, whereby it was assumed that paint work would have to be done every 3-4 years. The operation expenses could be brought down under good water conditions. The efficiency of the propeller could be maintained by regular cleaning. (Slight roughness caused by marine fouling causes a loss of up to 20 per cent). Whereas the entire floating body and the main parts of the machinery and the transmission have been developed for quantity production, the control system must still be further developed in this respect. The presumable service life is estimated to be approx. 15 years. The power output depends very strongly upon the flow...
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