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Georadiochemical evidence to weathering of mining residues of the Mansfeld mining district,Germany 总被引：1，自引：0，他引：1
Mining heaps are used as archives for the investigation of weathering processes. Aim of this work was to investigate the different
weathering behavior of heap materials derived from Kupferschiefer mining with respect to environmental hazard. For this purpose,
Kupferschiefer and slag material of two heaps of different age were examined regarding to the radionuclide distribution and
geochemical composition. By measuring of the local dose rate, performing digital autoradiography and gamma spectrometry the
radiological load of the heaps and the heap materials was determined. The geochemical characterization of the samples was
performed by XRF, ICP–OES and ICP–MS. The results show a clear higher radionuclide load of the younger slag heap. A depletion
of chalcophile and lithophile elements in the older slag was determined. Apart from a homogeneous radionuclide distribution,
considerable radionuclide enrichments in fossil fragments could be proven. The results reveal a different weathering behavior
of slag material in comparison to the Kupferschiefer depending on the chemical binding of the elements on organic and inorganic
species. Natural organic matter as well as apatite in Kupferschiefer act as retention barrier for some metals. 相似文献
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Environmental impact of uncontrolled waste disposal in mining and industrial areas in Central Germany 总被引：7，自引：0，他引：7
P. Schreck 《Environmental Geology》1998,35(1):66-72
The present-day landscape in Central Germany, in particular the region of Leipzig, Halle and Bitterfeld, is characterized
by the scars of former industrial activities. Vast districts have been devastated by lignite strip mining. Industrial and
domestic waste, residues from ore smelting, and highly toxic waste products from petrochemical plants and pesticide production
were deposited in abandoned pits near population centers. The chief effects of waste on the environment are the contamination
of groundwater by dissolved pollutants, the acidification of soil and water by the oxidation of pyrite-containing mining waste,
and the salinization of shallow aquifers by rising brines from adjacent confined groundwater affected by mining. The consequences
for the region are serious: mining lakes used for recreational purposes are contaminated by leachates from adjacent waste
dumps. Pyrite-containing refuse from lignite mining under oxidation gives rise to the acidification of surface and groundwater,
a basic condition for pollutant mobilization. In former metal mining districts, metalliferous and radioactive residues from
smelting jeopardize public health. These effects are described in detail using three case studies.
Received: 30 July 1996 · Accepted: 24 February 1997 相似文献
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Using Reverse Viewshed Analysis to Assess the Location Correctness of Visually Generated VGI 总被引：2，自引：1，他引：1
With the increased availability of user generated data, assessing the quality and credibility of such data becomes important. In this article, we propose to assess the location correctness of visually generated Volunteered Geographic Information (VGI) as a quality reference measure. The location correctness is determined by checking the visibility of the point of interest from the position of the visually generated VGI (observer point); as an example we utilize Flickr photographs. Therefore we first collect all Flickr photographs that conform to a certain point of interest through their textual labelling. Then we conduct a reverse viewshed analysis for the point of interest to determine if it lies within the area of visibility of the observer points. If the point of interest lies outside the visibility of a given observer point, the respective geotagged image is considered to be incorrectly geotagged. In this way, we analyze sample datasets of photographs and make observations regarding the dependency of certain user/photo metadata and (in)correct geotags and labels. In future the dependency relationship between the location correctness and user/photo metadata can be used to automatically infer user credibility. In other words, attributes such as profile completeness, together with location correctness, can serve as a weighted score to assess credibility. 相似文献
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