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Hong Seok-Hwi Yoo Dong-Geun Lee Gwang-Soo Kim Jin Cheul Yi Sangheon Kim Gil-Young Bahk Jang-Jun Yu Shin 《Marine Geophysical Researches》2022,43(4):1-18
Marine Geophysical Research - This study entails the characterization of the depositional environment of the Hupo Basin shelf. By means of sedimentary structure analysis, grain size, textures,... 相似文献
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Seok-Hwi Kim Kangjoo Kim Minhyung Lee Hwa-Jin Jeong Won-Jang Kim Jong-Gyu Park Jae-sam Yang 《Estuaries and Coasts》2009,32(6):1165-1175
Sediment and water quality were investigated in an artificial coastal lake (Saemangeum Lake, Korea) that was formed by constructing
a 33-km long sea-dyke offshore from the mouths of two adjacent rivers, which discharge into the Yellow Sea. Sediment showed
drastic increases in fine fraction (silt and clay) after the dyke construction. TN, TP, and OC contents in the sediment showed
the similar spatial variation to that of fine fraction. A mixing model indicated benthic fluxes of nutrients such as PO4, NH4, and SiO2, which were considerably elevated during the summer monsoon season. It is revealed that this phenomenon was associated with
the development of strong salinity stratification, elevated water temperature, and increased groundwater discharge. However,
a change in the sedimentation environment due to dyke construction is suggested as the primary reason for the enhanced benthic
fluxes. 相似文献
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Kangjoo Kim Hyun-Jung Kim Byoung-Young Choi Seok-Hwi Kim Ki-hoon Park Eungyu Park Dong-Chan Koh Seong-Taek Yun 《Applied Geochemistry》2008
Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO4 concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO4, supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO3 at shallow depths and by SO4 reduction at the greater depths. Isotopic and mass balance analyses revealed that NO3 and SO4 in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area. 相似文献
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Byoung-Young Choi Hyeon-Jung Kim Kangjoo Kim Seok-Hwi Kim Hwa-Jin Jeong Eungyu Park Seong-Taek Yun 《Environmental Geology》2008,54(2):335-345
Vertical variations of redox chemistry and groundwater quality were investigated in an alluvial aquifer beneath an agricultural
area, in which deep groundwaters are free of NO3, Fe, and Mn problems that are frequently encountered during the development of alluvial groundwaters. This study was performed
to identify and evaluate vertical chemical processes attenuating these chemical species in the study area. For this study,
the processes affecting groundwater chemistry were identified by factor analysis (FA) and the groundwater samples collected
from six multilevel samplers were hierarchically classified into three different redox zones by cluster analysis (CA) based
on the similarity of geochemical features. FA results indicated three major factors affecting the overall water chemistry:
agricultural activities (factor 1), redox reactions (factor 2), and remnant seawater (factor 3). The groundwater quality in
the study area was revealed to be controlled by a series of different redox reactions, resulting in different redox zones
as a function of depth. It was also revealed that the low Fe and Mn levels in the groundwater of the deeper part are associated
with sulfate reduction, which led to precipitation of Fe as iron sulfide and adsorption of Mn on it. 相似文献
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