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961.
The Norwegian Government has initiated a plan to reduce agricultural pollution. One of the projects in this plan is aimed at investigating the effects of different measures in order to evaluate their effects and costs.A set of experiments has been designed to estimate the effects of measures to reduce or control the use of fertilizers and erosion. The project started in 1985. It comprises continuous measurements in two water courses in each of four counties: one test drainage area where the relevant measures were implemented at the end of 1986, and one reference area where no specific measures are carried out. A series of chemical parameters are measured together with runoff and other hydrological and meteorogical data.The paper provides a preliminary analysis of the data collected in one of the counties during the period June 1985 to April 1988. It contains examples of analysis of covariance to show possible effects of the measures carried out in the test area.Natural variations in precipitation and pollution are large, making it difficult to see the effects of the measures without using statistical techniques to take the multivariability of the problem into account. Some effects can be shown with analysis of covariance. However, the relatively short measurement period makes it neccessary to be careful when interpreting the results.  相似文献   
962.
The definitions of the notions bio-indicator and water quality are critically reviewed; it is shown that both have been used ambiguously.The quality of the Wadden Sea is discussed using a number of indicators for pollution effects; the Wadden Sea is now an unsuitable environment for a number of marine mammals, and, to a lesser extent, for some bird species. It cannot be shown whether or not this pollution has any effect on r-selective species.Paper presented at a Symposium held on 14 and 15 October 1982, in Utrecht, The Netherlands.  相似文献   
963.
964.
Bruun HH  Fritzbøger B 《Ambio》2002,31(5):425-431
The recent decline in species richness in (semi)-natural habitats in northern Europe has largely been attributable to habitat destruction, and to subsequent limitation in seed dispersal among fragments. However, some habitat types were probably split up already in the historical landscape, but the segregated parts were probably not isolated to the present degree. This paper seeks evidence for livestock as vectors for propagules at 3 spatial scales in the past cultural landscape. Three main scales at which livestock acted as seed dispersers are important: free movement in the landscape (1-10 km), driving animals to mast feeding or to manors (10-50 km), and the export of living animals (hundreds of km). The emerging picture is for most plant species a dramatically decreased chance of dispersal in the modern landscape. The consequence is probably decreasing species richness in (semi)-natural plant communities, such as pasture, meadow, and heathland.  相似文献   
965.
966.
967.
When seeking to resolve complex land-management issues, geographical assessment of resources that are in short supply or in dispute can aid the communication of knowledge and the understanding among and between different stakeholders. In this paper, we illustrate how remote sensing and GIS can be used to gather and compile information regarding land-use activities and patterns among reindeer herders and other land users (forestry, mining, tourism, etc) in northern Sweden. The project represents a novel user-oriented effort largely based on the work carried out by the principal end user, i.e. the reindeer herders themselves. The basis for development of land-use plans for reindeer husbandry, was the following: to collect and digitally systemize traditional ecological and landscape knowledge of reindeer habitat use; to integrate this information with results from field inventories and satellite-based vegetation classifications; to map activities of other land users. The resulting land-use plans provide information that can facilitate consultation between the reindeer herders and other stakeholders and can facilitate operational work in reindeer management. This project can serve as a model for participatory involvement and planning, bringing indigenous knowledge and advanced remote-sensing techniques together in an interactive process.  相似文献   
968.
The ongoing program Clean Air for Europe (CAFE) is an initiative from the EU Commission to establish a coordinated effort to reach better air quality in the EU. The focus is on particulate matter as it has been shown to have large impact on human health. CAFE requested that WHO make a review of the latest findings on air pollutants and health to facilitate assessments of the different air pollutants and their health effects. The WHO review project on health aspects of air pollution in Europe confirmed that exposure to particulate matter (PM), despite the lower levels we face today, still poses a significant risk to human health. Using the recommended uniform risk coefficients for health impact assessment of PM, regardless of sources, premature mortality related to long-range transported anthropogenic particles has been estimated to be about 3500 deaths per year for the Swedish population, corresponding to a reduction in life expectancy of up to about seven months. The influence of local sources is more difficult to estimate due to large uncertainties when linking available risk coefficients to exposure data, but the estimates indicate about 1800 deaths brought forward each year with a life expectancy reduction of about 2-3 months. However, some sectors of the population are exposed to quite high locally induced concentrations and are likely to suffer excessive reductions in life expectancy. Since the literature increasingly supports assumptions that combustion related particles are associated with higher relative risks, further studies may shift the focus for abatement strategies. CAFE sets out to establish a general cost effective abatement strategy for atmospheric particles. Our results, based on studies of background exposure, show that long-range transported sulfate rich particles dominate the health effects of PM in Sweden. The same results would be found for the whole of Scandinavia and many countries influenced by transboundary air pollution. However, several health studies, including epidemiological studies with a finer spatial resolution, indicate that engine exhaust particles are more damaging to health than other particles. These contradictory findings must be understood and source specific risk estimates have to be established by expert bodies, otherwise it will not be possible to find the most cost effective abatement strategy for Europe. We are not happy with today's situation where every strategy to reduce PM concentrations is estimated to have the same impact per unit change in the mass concentration. Obviously there is a striking need to introduce more specific exposure variables and a higher geographical resolution in epidemiology as well as in health impact assessments.  相似文献   
969.
The fate of 13C-labelled phenanthrene and fluoranthene in different soil systems during biodegradation was studied. The soil humic acid fraction was isolated followed by structural characterisation using 13C-cross polarisation magic angle spinning nuclear magnetic resonance spectroscopy (13C-CPMAS-NMR). It could be demonstrated that especially the ratio between the concentrations of polycyclic aromatic hydrocarbons (PAHs) and soil humus matrix limits the usefulness of this analytical tool. Based on these results a ratio of 13C-activity(PAH)/13C-activity(soil) approximately 1.5/1.0 in the test material was suggested. The chemical transformation of a PAH and its bound residue formation in a soil system detected by changes of chemical shifts in the 13C-NMR spectrum was proven for the first time. Structural information obtained by NMR spectra were verified by alkaline hydrolysis of PAH/humus-associations and following identification of cleavage products. Ester-bound phenanthrene metabolites such as 1-hydroxy-2-naphthoic acid, ortho-phthalic acid and 3,4-dihydroxybenzoic acid were detected. Additional structural assignments indicated the presence of ether-bound phenanthrene derivatives as well. Using isotopic labelling techniques a quantitative evaluation of bound residue distribution was undertaken. Fifty to seventy percent of phenanthrene metabolites which could be related to the added 13C(1)-phenanthrene were ester bound via their carboxyl groups.  相似文献   
970.
ABSTRACT: Few hydrological models are applicable to pine flat-woods which are a mosaic of pine plantations and cypress swamps. Unique features of this system include ephemeral sheet flow, shallow dynamic ground water table, high rainfall and evapotranspiration, and high infiltration rates. A FLATWOODS model has been developed specifically for the cypress wetland-pine upland landscape by integrating a 2-D ground water model, a Variable-Source-Area (VAS)-based surface flow model, an evapotranspiration (ET) model, and an unsaturated water flow model. The FLATWOODS model utilizes a distributed approach by dividing the entire simulation domain into regular cells. It has the capability to continuously simulate the daily values of ground water table depth, ET, and soil moisture content distributions in a watershed. The model has been calibrated and validated with a 15-year runoff and a four-year ground water table data set from two different pine flat woods research watersheds in northern Florida. This model may be used for predicting hydrologic impacts of different forest management practices in the coastal regions.  相似文献   
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