Dynamisiertes Emissionskataster für den Freistaat Sachsen

A computer aided tool was created for the calculation of emission values in Saxony. It is based on the Geographic Information System ArcInfo and enables the emission values for past, present and future periods to be assessed. At present, the anthropogenic air pollutants SO₂, NO_x, CO, NH₃, NMVOC, TSP, CO₂, CH₄ and N₂O can be calculated by means of emission factors and statistical values. The tool is open to future expansions. The moduls represent the following emission groups: Power stations, large agricultural farms and large industrial plants as point sources, as well as transport, households, small consumer and the total emission of agriculture as area sources. The local resolution of emission values, the relationship of emission values to geographic or political territories, the inclusion of a high resolved digital street network, and the use of actual data concerning land use, density of population and density of build up areas are realized by GIS ArcInfo. The dynamic emission inventory can be used, alone or in conjunction with an atmospheric dispersion model, to assess trends in air quality.     

Modeling biogeochemical processes of phosphorus for global food supply

Harvests of crops, their trade and consumption, soil erosion, fertilization and recycling of organic waste generate fluxes of phosphorus in and out of the soil that continuously change the worldwide spatial distribution of total phosphorus in arable soils. Furthermore, due to variability in the properties of the virgin soils and the different histories of agricultural practices, on a planetary scale, the distribution of total soil phosphorus is very heterogeneous. There are two key relationships that determine how this distribution and its change over time affect crop yields. One is the relationship between total soil phosphorus and bioavailable soil phosphorus and the second is the relationship between bioavailable soil phosphorus and yields. Both of these depend on environmental variables such as soil properties and climate. We propose a model in which these relationships are described probabilistically and integrated with the dynamic feedbacks of P cycling in the human ecosystem. The model we propose is a first step towards evaluating the large-scale effects of different nutrient management scenarios. One application of particular interest is to evaluate the vulnerability of different regions to an increased scarcity in P mineral fertilizers. Another is to evaluate different regions’ deficiency in total soil phosphorus compared with the level at which they could sustain their maximum potential yield without external mineral inputs of phosphorus but solely by recycling organic matter to close the nutrient cycle.     

Analytical solution for estimating storage efficiency of geologic sequestration of CO2

During injection of carbon dioxide (CO₂) into deep saline aquifers, the available pore volume of the aquifer may be used inefficiently, thereby decreasing the effective capacity of the repository for CO₂ storage. Storage efficiency is the fraction of the available pore space that is utilized for CO₂ storage, or, in other words, it is the ratio between the volume of stored CO₂ and the maximum available pore volume. In this note, we derive and present simple analytical expressions for estimating CO₂ storage efficiency under the scenario of a constant-rate injection of CO₂ into a confined, homogeneous, isotropic, saline aquifer. The expressions for storage efficiency are derived from models developed previously by other researchers describing the shape of the CO₂-brine interface. The storage efficiency of CO₂ is found to depend on three dimensionless groups, namely: (1) the residual saturation of brine after displacement by CO₂; (2) the ratio of CO₂ mobility to brine mobility; (3) a dimensionless group (which we call a “gravity factor”) that quantifies the importance of CO₂ buoyancy relative to CO₂ injection rate. In the particular case of negligible residual brine saturation and negligible buoyancy effects, the storage efficiency is approximately equal to the ratio of the CO₂ viscosity to the brine viscosity. Storage efficiency decreases as the gravity factor increases, because the buoyancy of the CO₂ causes it to occupy a thin layer at the top of the confined formation, while leaving the lower part of the aquifer under-utilized. Estimates of storage efficiency from our simple analytical expressions are in reasonable agreement with values calculated from simulations performed with more complicated multi-phase-flow simulation software. Therefore, we suggest that the analytical expressions presented herein could be used as a simple and rapid tool to screen the technical or economic feasibility of a proposed CO₂ injection scenario.     

Alkyl nitrate photochemistry during the tropospheric organic chemistry experiment

Alkyl nitrates (C₁–C₅) were measured at two sites (near urban and rural) in southeast England during the Tropospheric Organic Chemistry Experiment (TORCH). Methyl nitrate was the dominant species during both campaigns accounting for on average about one third of the total measured alkyl nitrates. High mixing ratios (>50 pptv) and variability of methyl nitrate were observed at the near urban site (TORCH1) that were not seen at the rural site (TORCH2) and which could not be explained by local photochemical production or direct emissions. The diurnal variation of methyl nitrate during TORCH1 showed a morning maximum that would be consistent with nighttime chemistry followed by transport to the surface by boundary layer dynamics. Similarly, elevated morning mixing ratios were also observed during TORCH2 although the magnitudes were much smaller. As a result, methyl nitrate could represent a tracer for nighttime chemistry seen at the ground the following day. At both campaigns, the dominant source of short chain alkyl nitrates and carbonyl precursor radicals (≤C₄) were from decomposition of larger compounds. The magnitude of the source increased with decreasing carbon number consistent with increasing total precursor abundance. Non-photochemical emissions of acetaldehyde and acetone could not be accounted for by automobile exhaust emissions alone and indicated that other direct sources are likely important in this environment.     

Toxaphene chemistry: separation and characterisation of selected enantiomers of the Polychloropinene mixtures

The primary goal for the study presented here was the preparation and characterisation of enantiomeric pure chlorobornane standards (Toxaphene). In this context, we partially modeled the procedure for Polychloropinene production in the former USSR. The initial reaction was ionic addition of hydrogen chloride to (1S)-alpha-pinene resulting predominantly in (1S)-2-endo-chlorobornane. Further photochlorination gave mixtures of chlorinated terpenes with different average content of Cl per molecule. The resulting mixtures were separated on a silica-gel column and a number of known hepta to decachlorobornanes were identified in fractions with the help of NMR and GC (using electron capture and mass spectrometric detection)--but in very unusual ratios as compared to the technical Toxaphene mixture formerly produced by Hercules (USA). Also several previously unknown congeners were isolated or detected. Three of the isolated congeners were obtained in crystalline state and X-ray crystallography showed their enantiomeric purity.     

Atmospheric transport of persistent organic pollutants (POPs) to Bjørnøya (Bear island)

A first medium term monitoring of atmospheric transport and distribution for persistent organic pollutants (POPs) in Bj?rn?ya (Bear island) air samples has been performed in the period between week 51/1999 and week 28/2003. A total of 50 single compounds consisting of polychlorinated biphenyls (33 congeners), hexachlorobenzene (HCB), hexachlorocyclohexane isomers (alpha-, beta-, gamma-HCH), alpha-endosulfan, cyclodiene pesticides (chlordanes, nonachlor-isomers, oxy-chlordane, heptachlor and chlordane) as well as dichlorodiphenyltrichloroethane (DDT) derivatives were analysed and quantified. Atmospheric transport of POPs was identified as an important contamination source for the island. PCBs, HCB and HCH isomers were the predominant POP groups, contributing with 70-90% to the overall POP burden quantified in the Bj?rn?ya air samples. The highest concentration levels for a single compound were found for HCB (25-35 pg m(-3)). However, the sum of 33 PCB congeners was found to be in the same concentration range (annual means between 15 and 30 pg m(-3)). Cyclodiene pesticides, DDT derivatives and alpha-endosulfan were identified as minor contaminants. Several atmospheric long-range transport episodes were identified and characterised. Indications for industrial emissions as well as agricultural sources were found for the respective atmospheric transport episodes. A first simple statistical correlation assessment showed that for long-range transport of pollution, the local meteorological situation is not as important as the air mass properties integrated over the time period of the transport event. The local weather situation, on the other hand, is important when investigating deposition rates and up-take/accumulation properties in the local ecosystem. Based upon chemical data interpretation, valuable information about the influence of primary and secondary sources on the air mass contamination with chlorinated insecticides (e.g., HCHs) was found and discussed. The interdisciplinary interpretation of contaminant data using statistical methods, chemical analysis, meteorological modelling and classical meteorological information for a comprehensive evaluation of atmospheric long range transport into the European Arctic (Bj?rn?ya) has proven to be a highly versatile tool not only for atmospheric scientists but also with strong potential for regulatory purposes.     

Assessing multiple novel tracers to improve the understanding of the contribution of agricultural farm waste to diffuse water pollution

A study was undertaken on drained and undrained 1 ha grassland lysimeters to assess the effectiveness of multiple novel tracing techniques in understanding how agricultural slurry waste moves from land to water. Artificial fluorescent particles designed to mimic the size and density of organic slurry particles were found to move off the grassland via inter-flow (surface + lateral through-flow) and drain-flow. Where both pathways were present the drains carried the greater number of particles. The results of the natural fluorescence and δ13C of water samples were inconclusive. Natural fluorescence was higher from slurry-amended lysimeters than from zero-slurry lysimeters, however, a fluorescence decay experiment suggested that no slurry signal should be present given the time between slurry application and the onset of drainage. The δ13C values of >0.7 microm and <0.7 microm material in drainage were varied and unrelated to discharge. The mean value of >0.7 microm δ13C in water from the drain-flow pathways was higher from the lysimeter which had received naturally enriched maize slurry compared to the lysimeter which received grass slurry indicating a contribution of slurry-derived material. Values of <0.7 microm δ13C from the same pathway, however, produced counter intuitive trends and may indicate that different fractions of the slurry have different δ13C values.     

Mapping Patterns of Human Use and Potential Resource Conflicts on Public Lands

Focusing on a 2.2 million hectare area surrounding the Lolo National Forest in western Montana, USA, we illustrate a GIS method for predicting patterns of human use on public lands and highlighting potential for impacts on fish and wildlife species. Data inputs include human population count (derived from the 1990 Census), roads and trails, and the predicted distributions of bull trout (Salvelinus confluentus) and 41 terrestrial vertebrates of special concern. Because results highlight areas where conflicts between humans and resources may occur, they are of potential use to land managers. This approach can be applied wherever data are available, and inputs can be varied according to the topics of interest.