• Journal of the Korean earth science society
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• v.43 no.1
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• pp.165-175
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• 2022

Earthquakes have occurred owing to movements on a fault since several billion years ago. Research on the relationship between earthquakes and groundwater began in the 1960s in the United States, but related works, including hydrogeochemistry research, only began in the 2010s in South Korea. In this study, domestic studies on the relationship between earthquakes and groundwater until 2021 were collected from the Web of Science and characterized by subject area (groundwater level, hydrogeochemistry, combination of the two, and others). The results showed that the number of published articles per year was positively correlated with the 2011 Tohoku earthquake, 2016 Gyeongju earthquake, and 2017 Pohang earthquake, with the maximum numbers observed in 2011, 2018, 2019, and 2020. Most studies on the relationship between earthquakes and groundwater level addressed groundwater level fluctuations in the duration of the subject earthquake, with little consideration of the precursors. Groundwater level monitoring data, as well as hydrogeochemical information and microbial communities, may contribute to a more detailed understanding of groundwater flow and chemical reactions in bedrock caused by earthquakes. Therefore, the establishment of a national groundwater monitoring network for seismic monitoring and prediction is required.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.328-332
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• 2006

본 연구는 농경활동이 활발한 만경강 하천부지에서 지하수의 수리지질 및 수리지화학적 특성을 고찰하고 B과 Sr 동위원소를 이용하여 지하수 수질 변화에 영향을 미치는 요인을 알아보고자 하였다. 연구 결과 만경강 하천부지는 지표로부터 실트질 모래층, 자갈모래층, 풍화대로 크게 3등분되며 투수성은 모래자갈층에서 가장 좋고 그 다음으로 풍화대, 실트질 모래층 순이었다. 화학성분 검층과 ${\delta}^{11}B,\;^{87}Sr/^{86}Sr$ 동위원소 분석결과 지하수 조성은 해수와 농업 활동에 의한 영향을 크게 받는 것으로 나타났다. 화학성분 검층 결과 해수 영향은 하천과 도로제방 사이 중간정도 까지인 것으로 사료되었으며 ${\delta}^{11}B$ 분석 결과 자갈모래층과 풍화대 지하수는 해수의 영향을 받는 것이 확인되었다. 본 연구지역 지하수는 지층 특성에 의한 영향으로 천층지하수는 토지이용에 따른 농업활동의 영향을 받으며 지표하 10m 이하의 지하수는 해수의 영향을 받는 것으로 사료되었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.229-232
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• 2002

대전 북부 화강암지역 내 심도 500m까지 굴착한 시추공에 다중패커 시스템(Multi-packer system)을 이용하여 구간별로 지하수 시료채취를 수행하고, 시추공 지하수에 대한 지화학 특성 연구를 수행하였다. 다중패커 시스템에 의해 구간별로 격리된 시추공 지하수의 수리화학자료는 구간별로 특징적인 화학조성을 나타낸다 다중패커 시스탬이 설치된 직후 채취한 지하수 시료와 일정시간이 경과한 후 채취한 시료간에는 시기별로 화학특성의 차이를 보이는데 이는 시추당시 사용된 시추수의 영향 때문인 것으로 사료된다. 또한 심도 115m를 기준으로 상부구간과 하부구간에 지화학 특성에서 큰 차이를 보이고 있는데 이는 시추공 굴착당시 단열대의 붕괴로 인해 시공된 그라우팅의 영향 때문이다. 이상치를 보이는 115m 구간을 제외하고, 시추공 지하수의 지화학 자료는 구간별로 명확히 구별되어 화강암 지역에서 지하수의 유동은 단열분포특성에 영향을 받음이 확인되었다.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.435-450
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• 2005

The purpose of the study is to analyze the hydrogeochemical characteristics by multivariate statistical method, to interpret the hydrogeochemical processes for the new variables calculated from principal components analysis (PCA), and to infer the groundwater flow and circulation mechanism by applying the geostatistical methods for each element and principal component. Chloride and nitrate are the most influencing components for groundwater quality, and the contents of $NO_3$ increased by the input of agricultural activities show the largest variation. The results of PCA, a multivariate statistical method, show that the first three principal components explain $73.9\%$ of the total variance. PC1 indicates the increase of dissolved ions, PC2 is related with the dissolution of carbonate minerals and nitrate contamination, and PC3 shows the effect of cation exchange process and silicate mineral dissolution. From the results of experimental semivariogram, the components of groundwater are divided into two groups: one group includes electrical conductivity (EC), Cl, Na, and $NO_3$, and the other includes $HCO_3,\;SiO_2,$ Ca, and Sr. The results for spatial distribution of groundwater components showed that EC, Cl, and Na increased with approaching the coastal line and nitrate has close relationship with the presence of agricultural land. These components are also correlated with the topographic features reflecting the groundwater recharge effect. The kriging analysis by using principal components shows that PC 1 has the different spatial distribution of Cl, Na, and EC, possibly due to the influence of pH, Ca, Sr, and $HCO_3$ for PC1. It was considered that the linear anomaly zone of PC2 in western area was caused by the dissolution of carbonate mineral. Consequently, the application of multivariate and geostatistical methods for groundwater in the study area is very useful for determining the quantitative analysis of water quality data and the characteristics of spatial distribution.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.167-179
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• 2016

Water quality of Oseepchun, Dogye area, was investigated quantitatively for its origin and hydrogeochemistry in relation to the influence of groundwater. Groundwater appears to be the principal source of Oseepchun from the water-quality monitoring data including redox potentials, composition of dissolved ions and their correlations, hydrogen and oxygen stable isotopic ratios, and the distribution and occurrence of contaminants. Water-quality type of the surface water was grouped by the water-rock interactions as $Ca-HCO_3$ type originated from carbonated bed-rocks in the Joseon Supergroup, (Ca, Mg)-$SO_4$ type related with dissolution of surfide minerals in coal beds of Pyeongan Supergroup, and (Ca, Mg)-($HCO_3$, $SO_4$) type of the mixed one. Locally water pollution occurs by high $SO_4$ from mine drainage and $NO_3$ from waste-treatment facility. Intensive precipitation in summer has no effect on the water type of Oseepchun, but increases the inflow of nitrate and chloride originated from land surface. Results of this study direct that groundwater-surface water interaction is intimate, and thus surface-water resource management should begin with groundwater characterization.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.72-84
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• 2008

This study was carried out to provide proper management plans for small portable water supply system in the Nonsan area through water quality monitoring, hydrogeochemical investigation and multivariate statistical analyses. Nonsan area is a typical rural area heavily depending on small water supply system for portable usage. Geology of the area is composed of granite dominantly along with metasedimentary rocks, gneiss and volcanic rocks. The monitoring results of small portable water supply system showed that 13-21% of groundwaters have exceeded the groundwater standard for drinking water, which is 5 to 8 times higher than the results from the whole country survey (2.5% in average). The major components exceeding the standard limits are nitrate-nitrogen, turbidity, total coliform, bacteria, fluoride and arsenic. High nitrate contamination observed at southern and northern parts of the study area seems to be caused by cultivation practices such as greenhouses. Although Ca and $HCO_3$ are dominant species in groundwater, concentrations of Na, Cl and $NO_3$ have increased at the granitic area indicating anthropogenic contamination. The groundwaters are divided into 2 groups, granite and metasedimentary rock/gneiss areas, with the second principal component presenting anthropogenic pollution by cultivation and residence from the principal components analysis. The discriminant analysis, with an error of 5.56% between initial classification and prediction on geology, can explain more clearly the geochemical characteristics of groundwaters by geology than the principal components analysis. Based on the obtained results, it is considered that the multivariate statistical analysis can be used as an effective method to analyze the integrated hydrogeochemical characteristics and to clearly discriminate variations of the groundwater quality. The research results of small potable water supply system in the study area showed that the groundwater chemistry is determined by the mixed influence of land use, soil properties, and topography which are controlled by geology. To properly control and manage small water supply systems for central and local governments, it is recommended to construct a total database system for groundwater environment including geology, land use, and topography.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.579-582
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• 2003

This study is a part of the project to identify water-quality degradation mechanism due to Fe and Mn in the river-bank infiltration system in the Changwon city, Kyungsangnam-Do. Results of hydrogeochemical logging indicated that the matrix of the river bank affects groundwater quality, probably related with the hydraulic conductivities of the different layers of bank deposits. Electric conductivity logging data clearly show various layers of groundwater flows. Further studies are necessary to identify mechanisms of increasing dissolved oxygen contents with depths at some monitoring wells.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.369-372
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• 2004

This study presents the hydrogeochmical investigation to know the effect of geology and sources for water quality in small potable water supply system at rural area. The results of water quality in Geumsan area showed the 3.2% of water samples exceeded the limit of drinking water standard by bacteria. The hydrochemical investigation results indicated the high EC, Ca and HCO$_3$ in surface water and metasedimentary rocks and this is caused by the dissolution of calc-slicate minerals of metasedimentary rocks.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.276-279
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• 2005

마금산온천 지역에 대한 기초적인 지화학 조사를 수행하였다. 연구지역내에는 일반 지하수와 온천수가 함께 산출되며, 온천수의 지화학적 특성은 마금산 온천이 해수의 영향을 받았음을 지시한다. 또한 주변의 일반지하수와의 혼합정도에 따라 지화학적 특성이 변화하고 있으며, 일반지하수 또한 온천수의 영향을 지역적으로 받고 있는 것으로 판단된다. 따라서 마금산온천을 생성시킨 지열수가 연구지역의 지하수체계에 광범위하게 영향을 주고 있다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.115-131
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• 2013

The Mizunami Underground Laboratory (MIU) Project is a comprehensive research project investigating the deep underground environment within crystalline rock being conducted by Japan Atomic Energy Agency. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of 20 years. The overall project goals of the MIU Project from Phase I through to Phase III are: 1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and 2) to develop a range of engineering for deep underground application. For the overall project goals 1), the Phase I goals were set to construct models of the geological environment from all surface-based investigation results that describe the geological environment prior to excavation and predict excavation response. For the overall project goals 2), the Phase I goals were set to formulate detailed design concepts and a construction plan for the underground facilities. This paper introduces geosynthesis procedures for the investigation and assessment of the hydrochemistry of groundwater in crystalline rock.