• Title/Summary/Keyword: geochemical concepts

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Geochemical Concept and Technical Development of Geological $CO_2$ Sequestration for Reduction of $CO_2$ (이산화탄소 저감을 위한 지중처분기술의 지구화학적 개념과 연구개발 동향)

  • Chae, Gi-Tak;Yun, Seong-Taek;Choi, Byoug-Youg;Kim, Kang-Joo;Shevalier, M.
    • Economic and Environmental Geology
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    • v.38 no.1
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    • pp.1-22
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    • 2005
  • Carbon dioxide ($CO_2$) is the greatest contributor among the major greenhouse gases covered by the Kyoto Protocol. Therefore, substantial efforts for the control and reduction of $CO_2$ emissions, including increased efficiency of fossil fuel energy usage, development of energy sources with lower carbon content, and increased reliability on alternative energy sources, are being performed worldwide. However, development and industrial application of $CO_2$ sequestration techniques are needed to meet the requirements of the Kyoto Protocol. Among the $CO_2$ sequestration methods developed, geological sequestration methods such as the storage in deep aquifers, deep coal seams and oil and gas reservoirs and the mineral carbonation is considered most favorable because of its stability and environmental effectiveness. In this review, geochemical concepts and technologic development of geologic sequestration technology, especially the storage in deep aquifers and the mineral carbonation, are discussed. The weakness and strengths for each of geologic sequestration methods, are also reviewed.

On Mathematical Representation and Integration Theory for GIS Application of Remote Sensing and Geological Data

  • Moon, Woo-Il M.
    • Korean Journal of Remote Sensing
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    • v.10 no.2
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    • pp.37-48
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    • 1994
  • In spatial information processing, particularly in non-renewable resource exploration, the spatial data sets, including remote sensing, geophysical and geochemical data, have to be geocoded onto a reference map and integrated for the final analysis and interpretation. Application of a computer based GIS(Geographical Information System of Geological Information System) at some point of the spatial data integration/fusion processing is now a logical and essential step. It should, however, be pointed out that the basic concepts of the GIS based spatial data fusion were developed with insufficient mathematical understanding of spatial characteristics or quantitative modeling framwork of the data. Furthermore many remote sensing and geological data sets, available for many exploration projects, are spatially incomplete in coverage and interduce spatially uneven information distribution. In addition, spectral information of many spatial data sets is often imprecise due to digital rescaling. Direct applications of GIS systems to spatial data fusion can therefore result in seriously erroneous final results. To resolve this problem, some of the important mathematical information representation techniques are briefly reviewed and discussed in this paper with condideration of spatial and spectral characteristics of the common remote sensing and exploration data. They include the basic probabilistic approach, the evidential belief function approach (Dempster-Shafer method) and the fuzzy logic approach. Even though the basic concepts of these three approaches are different, proper application of the techniques and careful interpretation of the final results are expected to yield acceptable conclusions in cach case. Actual tests with real data (Moon, 1990a; An etal., 1991, 1992, 1993) have shown that implementation and application of the methods discussed in this paper consistently provide more accurate final results than most direct applications of GIS techniques.

A Study on Temporal-Spatial Water Exchange Characteristics in Gamak Bay using a Method for Calculating Residence Time and Flushing Time (체류시간과 교체시간 계산을 통한 가막만의 시·공간적 해수교환 특성 연구)

  • Kim, Jin Ho;Lee, Won Chan;Hong, Sok Jin;Park, Jung Hyun;Kim, Chung Sook;Jung, Woo Sung;Kim, Dong-Myung
    • Journal of Environmental Science International
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    • v.25 no.8
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    • pp.1087-1095
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    • 2016
  • The concepts of residence time and flushing time can be used to explain the exchange and transport of water or materials in a coastal sea. The application of these transport time scales are widespread in biological, hydrological, and geochemical studies. The water quality of the system crucially depends on the residence time and flushing time of a particle in the system. In this study, the residence and flushing time in Gamak Bay were calculated using the numerical model, EFDC, which includes a particle tracking module. The average residence time was 55 days in the inner bay, and the flushing time for Gamak Bay was about 44.8 days, according to the simulation. This means that it takes about 2 months for land and aquaculture generated particles to be transported out of Gamak Bay, which can lead to substances accumulating in the bay. These results show the relationships between the transport time scale and physical the properties of the embayment. The findings of this study will improves understanding of the water and material transport processes in Gamak Bay and will be important when assessing the potential impact of coastal development on water quality conditions.