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191.
192.
Groundwater nitrate pollution in the recharge zone of a regional Quaternary flow system (Wielkopolska region, Poland) 总被引:2,自引:0,他引:2
Krzysztof Dragon 《Environmental Earth Sciences》2013,68(7):2099-2109
The present study examines the behaviour of nitrate in the recharge zone of a regional Quaternary flow system. The presence of contaminated groundwater with high nitrate content in the shallow part of the flow system was documented. Tritium analyses confirmed that these contaminants can migrate downward. A high downward gradient exists in the study area, extending into the regions of groundwater extraction. In the unconfined part of the flow system, which is the most vulnerable to pollution, a high concentration of nitrate was found to occur at great depth. However, denitrification processes limit nitrate migration. As a result, in the deeper parts of the flow system in regions under confined conditions, an absence of nitrate was observed, and a higher sulphate concentration and total hardness were evident. The denitrification was also confirmed by the existence of a high gaseous N2 concentration. It was documented that denitrification occurs in both the confined and unconfined parts of the flow system, but the potential for denitrification is higher in the confined parts (leading to the disappearance of nitrate in deep aquifers). Autotrophic denitrification supported by sulphide compounds was indicated as the dominant denitrification process. 相似文献
193.
Krzysztof Raczyński 《Water Resources》2020,47(1):29-40
Water Resources - The objective of this paper is the assessment of the effect of a multifunctional mid-size retention reservoir on the occurrence of floods and low flows. The study object was... 相似文献
194.
Ladislav Bnesz Josef Hromada Janusz Kozlowski Krzysztof Sobczyk Maciej Pawlikowski 《Geoarchaeology》1995,10(4):237-255
The site of Moravany-Žakovska in western Slovakia is situated in a loessic terrain and is dated to the end of the Late Glacial Maximum. This article shows the importance of analyzing the 0.01-0.1 mm fraction to interpret the sedimentological environment and a number of measured anthropogenic indices, such as burnt quartz grains, charcoal, radiolarite chips, microflakes, and microfragments of bone. Analysis of the profile of the site through time reveals the relationship between occupational levels and phases of slope wash that occurred during wetter climatic episodes; these are separated by phases of aeolian sedimentation. At the same time, analysis of anthropogenic indices in this size fraction permitted the identification of occupational levels, including those not recorded by macrofinds. Analysis of anthropogenic indices in horizontal exposures enabled the identification of latent settlement structures such as hearths, areas of radiolarite processing, zones where mineral dyes were prepared, and other structures not recorded by macrofinds. 相似文献