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 "B 1.2: Efficient water use in limestone areas - Phase 2" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre durchgeführt. The elevated areas of Northern Thailand highlands are inhabited by ethnic minorities. On the other hand, the Thai majority prefers the valley bottoms. Population growth of all groups, reforestation and commercialisation of agriculture lead to an increasing pressure on land and water resources. Therefore, intensified land and water use systems are desired which are resource conserving at the same time. Here, special problem areas are the karstic limestone catchments due to the limited of surface waters.Own pre-investigations together with subproject A1 have shown, that land use systems there are subsistence oriented and local farmers do not use irrigation. But they would like to develop such technology, especially in order to increase staple crop production (highland rice, maize). But lack of irrigation possibilities is also responsible for the lack of diversification of land use systems with respect to orchards. One possibility to increase staple crop yields is to prolong the vegetation period by use of water harvesting technologies. Aim of this project is to develop such low cost water harvesting technologies (together with subproject B3.1) based on a participatory approach and to model the effect of these on the water balance at the catchments scale. This will be done on the basis of the previous variability studies and should lead to model tools, which allow to evaluate ex ante SFB innovation effects on the water balance. The project area is the Bor Krai catchments. Here, weirs will be installed to quantify surface water availability. An investigation plot will be situated near the village of Bor Krai which serves for water balance measurements (TDR/densitometry) and at the same time as demonstration plot for the local community. Here water harvesting by means of filling the soils field capacity at the end of the rainy season by gravity irrigation in order to prolong the vegetation period will be researched. Through cropping of participatory evaluated varieties the crop yield should be increased. The water consumption of traditionally managed and dominant crops (including orchards) will be measured at three further sites in the catchment (TDR, tensiometer). The water balance of the soil cover in the karst catchment will be based on the coupling of a SOTER map with a water transport model. The data base will be completed by soil type mapping, spatially randomised collection of soil physical properties (texture, bulk density, infiltration, water retention curve) and determination of the ku-function at two representative sites. As project results the available water amount for irrigation purposes will be quantified. The effective use of this water reserve will lead to increased productivity of the dominant crops and limitations to orchard productivity will be reduced. (abridged text)
Das Projekt "D 7: Research for improved fish nutrition and fish health in upland aquaculture systems in Yen Chau, Son La Province, Northern Vietnam" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Tierproduktion in den Tropen und Subtropen (480), Fachgebiet Aquakultur-Systeme und Tierernährung in den Tropen und Subtropen (490i) durchgeführt. Background: Aquaculture significantly contributes to protein supply and cash income of Black Thai farmers in Yen Chau, Son La province, Northern Vietnam. Fish is produced for cash income (2/3rd) and subsistence (1/3rd) while self recruiting species (small fish, crustaceans and molluscs) provide additional protein for home consumption. The current aquaculture system is a polyculture of the macroherbivorous grass carp as main species together with 3-5 other non-herbivorous fish species like Common Carp, Silver Carp, Bighead Carp, Mud Carp, Silver Barb and Nile Tilapia. With a rearing period of 21 months, the productivity of the aquaculture system amounts to 1.54 +- 0.33 t ha-1 a-1 and can be characterized as low. Nearly each household has at least one pond, which serves multiple purposes and is operated as a flow-through-system. The steady water flow is advantageous for the culture of grass carp, but causes a continuous loss of nutrients and high turbidity and thereby limits the development of phytoplankton and zooplankton which are natural food for non-herbivorous species. The farmers are using mainly green leaves (banana, bamboo, cassava, maize and grass) and crop residues (rice bran, rice husk, cassava root peel, distillery residue) as feed input, which is available to Grass Carp while non-herbivorous fish species are not fed specifically. Manure is used as fertilizer. The uneaten parts of fed plants are sometimes accumulating in the pond over several years, resulting in heavy loads of organic matter causing oxygen depletion. Anaerobic sediment and water layers limit the development of zoobenthos and may provide a habitat for anaerobe disease agents. Since 2003 an unknown disease condition has been threatening Grass Carp production and is having a major economic impact on the earnings from fish farming in Yen Chau region. Other fish in the same ponds are not affected. Especially in March-April and in September-October the disease is causing high morbidity and mortalities of Grass Carp in affected ponds and is thereby decreasing the dietary protein supply and income generation of Black Thai farmers. Little is known about the definition or aetiology of the disease condition.
Das Projekt "Climate indicators on the local scale for past, present and future and platform data management" wird vom Umweltbundesamt gefördert und von Philipps-Universität Marburg, Fachgebiet Klimageographie und Umweltmodellierung durchgeführt. Predicting future climate change is in itself already difficult, especially in such complex ecosystems as the Andean mountain rain and dry forest as well as the Paramo. The common tools to simulate global climate change are global circulation models (GCM). Because of their coarse resolution they are not able to capture atmospheric processes affecting the local climate. For this reason a dynamical downscaling approach will be used to develop a highly resolved spatial and temporal Climatic Indicator System (hrCIS) to derive ecologically relevant climate change indicators affecting the ecosystems of South Ecuador. A local-limited area model (LAM) will be used to (i) generate a highly resolved gridded climatology for present day (hrCISpr) based on reanalysis data and (ii) to generate a highly resolved gridded climatology for projected future (hrCISpf) based on the new Representative Concentration Pathways (RCP) scenario data. The output of the LAM for present day will be validated with in-situ measurement data and satellite-derived products to ensure the accuracy of the model for the simulations of the projected future. On the basis of statistical analysis of both climatologies changes in climate indicators such as air temperature and precipitation regime will be described. The proper storage, curation and accessibility of environmental data is of crucial importance for global change research particularly for monitoring purposes. This proposal will offer an adequate data management system for the Platform for Biodiversity and Ecosystem Monitoring and Research. This will be archived by extending the web-based information management system FOR816DW (a data warehouse for collaborative ecological research units) with features like automatic upload interfaces, a workbench for integrative analysis and an user defined alert system, which will facilitate environmental monitoring for scientist as well as stakeholders. Beside the development of these innovations a main objective is the transfer of knowledge and information (know how, source code, and collection data) to our partners in Ecuador. For this, and to bring together the existing data sources, we cooperate with university and non-university parties in the joint establishment of a Data access platform for environmental data of the region. This will include considerations on long-term accessibility, which is envisaged by a data transfer to the planned German national data infrastructure GFBio.
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 "The fate of phosphorus in forest and treeline ecosystems in Ecuador" wird vom Umweltbundesamt gefördert und von Universität Tübingen, Fachbereich Geowissenschaften, Forschungsbereich Geographie durchgeführt. Even remote areas such as tropical montane forests suffer from continuously high atmospheric nitrogen (N) and phosphorus (P) deposition. In studies on ecosystem responses to atmospheric nutrient deposition, P cycling has played an underrated role compared to N, although P is thought to limit organism growth in main parts of the Tropics. Furthermore, the responses of tropical montane forests to atmospheric nutrient deposition might depend on the predicted climate change i.e., shifts in temperature and precipitation. Altitudinal gradients represent an ideal means to study environmental changes in tropical montane forests in southern Ecuador, because climate scenarios and unpublished trends in longer-term climate data predict increasing temperatures and decreased moisture which parallels the altitudinal gradient from 4000 m to 1000 m asl.Previous experiments, including the NUMEX experiment in Ecuador, showed that the main proportion of P added to forests to simulate atmospheric deposition was retained in soil. While total P pools in soil respond slowly to low P addition rates, the biological and geochemical processes underlying retention in the organic layer or in soil are expected to react faster. Our overarching objective is to assess the fate of fertilized P in the organic layer and in mineral soil and to elucidate the processes involved in P cycling in soil (immobilization and release rates by microorganisms, sorption/desorption, precipitation/dissolution) along the NUMEX-X altitudinal gradient (1000, 2000, 3000, 4000m; the latter including a Polylepis and a Páramo ecosystem). We will assess P fractions in soil and use a combination of 33P tracer studies and incubation experiments to disentangle biological and geochemical processes controlling P retention. The mechanistic understanding gathered by this proposal is crucial for predictions of ecosystems responses to the continuously high atmospheric N (and P) deposition, because single mechanisms might respond differently (and oppositionally) in the long run. Because the processes involved in P cycling are expected to respond faster to environmental changes than e.g., P pools in soil, these different responses are an essential basis to evaluate effects of environmental change and finally, to develop early-warning ecosystem indicators for environmental change.
Das Projekt "Coupling of the LM and ECHAMS/MESSy for consistently investigating chemistry and transport from the global to the regional scale" wird vom Umweltbundesamt gefördert und von Universität Bonn, Institut für Geowissenschaften durchgeführt. Numerical modelling of chemical processes in the atmosphere is essential to increase our understanding of atmospheric composition and its changes induced by human activity. In recent years, global-scale atmospheric models that calculate the concentration and processing of trace constituents in the atmosphere have been developed. However, for key problems like local air quality, (long-range) transport from local sources and the detailed interpretation of chemical measurements the development of high-resolution models is essential. Proper initial and boundary conditions also for chemical variables must be consistently provided in order to run high-resolution limited-area chemistry models. For the first time, we propose to develop and employ such a model that is driven by consistent meteorological and chemical fields. This will be achieved through coupling of the global ECHAM5/MESSy system with the Local Model (LM). First applications of the newly developed model LM/MESSy will serve to investigate its capabilities for (i) a detailed analysis of field measurements, (ii) the direct simulation of mesoscale chemical perturbations like dust and biomass burning plumes, and (iii) an assessment and eventually forecast of local air quality. On the medium-term, the novel tool, developed jointly within research organisations, will be made available for chemical weather forecasting.
Das Projekt "SP 2.2 QTL analysis and optimization of breeding schemes for improved nitrogen-use efficiency of maize and wheat for sustainable cropping systems in the North China Plain" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Pflanzenzüchtung, Saatgutforschung und Populationsgenetik (350), Fachgebiet Angewandte Genetik und Pflanzenzüchtung (350a) durchgeführt. In China, agriculture needs to be intensified by increasing the productivity per unit land. However, the possibility to improve yield by further increasing the amounts of input is very limited due to already very high input amounts of fertilizers and irrigation water in the present cropping system. Hence, the development and characterization of improved varieties, especially with regard to traits of utmost importance for sustainable resource use, such as nitrogen- (NUE) and water-use efficiency (WUE), is crucial for a sustainable agriculture in the North China Plain. The decision about the requirement of one common or two separate breeding programs for developing varieties adapted to low and high N fertilization strongly depends on an appropriate estimation of the correlation between yield at different fertilization levels. Therefore, maize and wheat varieties are evaluated in multiple locations in the North China Plain. Adopting novel breeding approaches based on doubled haploids (DH) can speed up the process of developing new varieties substantially and rapidly provides suitable cultivars for new cropping systems. Therefore, optimum breeding strategies for maize breeding are modeled and simulated to optimize alternative breeding schemes with respect to the optimum allocation of test resources using different optimization criteria. Modeling of production systems and material flows is a powerful tool to increase sustainable resource use by identifying cropping systems, which combine reduced inputs with high yields. However, an appropriate model requires knowledge about the genetics of crop growth and yield and its interaction with environmental factors. Therefore, maize and wheat populations developed by the Chinese partners in the first project phase are phenotyped in multi-location field trials and genotyped with molecular markers to map quantitative trait loci (QTL) for NUE.
Das Projekt "IWaTec - Integrated Water Technologies" wird vom Umweltbundesamt gefördert und von Universität Duisburg-Essen, Zentrum für Wasser- und Umweltforschung durchgeführt. Egypt passed a revolution and changed its political system, but many problems are still lacking a solution. Especially in the field of water the North African country has to face many challenges. Most urgent are strategies to manage the limited water resources. About 80% of the available water resources are consumed for agriculture and the rest are for domestic and industrial activities. The management of these resources is inefficient and a huge amount of fresh water is discarded. The shortage of water supply will definitely influence the economic and cultural development of Egypt. In 2010, Egypt was ranked number 8 out of 165 nations reviewed in the so-called Water Security Risk Index published by Maplecroft. The ranking of each country in the index depends mainly on four key factors, i.e. access to improved drinking water and sanitation, the availability of renewable water and the reliance on external supplies, the relationship between available water and supply demands, and the water dependency of each countrys economy. Based on this study, the situation of water in Egypt was identified as extremely risky. A number of programs and developed strategies aiming to efficiently manage the usage of water resources have been carried out in the last few years by the Egyptian Government. But all these activities, however, require the availability of trained and well-educated individuals in water technology fields. Unfortunately, the number of water science graduates are decreasing and also there are few teaching and training courses for water science offered in Egypt. However, there is still a demand for several well-structured and international programs to fill the gap and provide the Egyptian fresh graduates with the adequate and up-to-date theoretical and practical knowledge available for water technology. IWaTec is designed to fill parts of this gap.
Das Projekt "Assessment of the overall environmental exposure by silver ions originating from biocidal products" wird vom Umweltbundesamt gefördert und von Fraunhofer-Institut für Chemische Technologie durchgeführt. Due to its antibacterial activity, silver is of increasing importance for many products of everyday use,and for medicinal products. Silver is applied as a solution, as a suspension, and in nanoparticularform. Because of its increasing use and manifold applications, the environmental risk of silver has tobe investigated and assessed considering the potential pathways of entry, environmental concentrationsand ecotoxicological effects. We conducted a literature study to collect the data required for arisk assessment for silver compounds and silver nanoparticles. A preliminary risk assessment wasperformed based on this data.It is demonstrated that an environmental risk for the aquatic compartment and for sewage treatmentplants can be considered as small, but cannot be totally excluded. Prerequisite for the statement isthat the assumptions with respect to the concentration of silver ions in the environment can be validatedby chemical analyses.For soil and sediment, there is an indication for risk. Gaps in knowledge have been identified. Especiallyknowledge about the concentration of silver ions in the environment, the influence of changingenvironmental conditions (e.g. degradation of organic matter, modification of pH) on silver and silvernanoparticles and is limited.
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