• The Journal of Engineering Geology
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• v.33 no.4
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• pp.611-626
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• 2023

Overseas examples of the characterization stage of site selection proposed by the International Atomic Energy Agency were reviewed to highlight the factors necessary for consideration in the deep disposal of high-level radioactive waste. Studies in Sweden, Finland, the USA, and Canada were considered. Site investigations in Sweden and Finland commonly covered the fields of geology, hydrogeology, and hydrogeochemistry using similar field investigation techniques. The USA considered survey groups and factors under pre- and post-lockdown guidelines, as well as those for desaturated and saturated surveys. involving geophysical, hydrological, hydrogeological, hydrogeochemical, mechanical/physical, and thermal-characterization investigations. Canada provided a list of investigative methods for both preliminary and detailed site assessments including geological, physical, boring, hydrological, laboratory testing, and chemical analysis studies. Results of this study should elucidate site-selection investigation factors and survey methods applicable to Korea.

• Spatial Information Research
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• v.12 no.3
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• pp.275-283
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• 2004

In order to effectively, and accurately assess seawater intrusion in coastal area, multidisciplinary data including geophysical, well logging, and hydrogeochemical data should be managed in systematical way. Such systematical management of data is critical key to improve the re-usability of the data as well as the accuracy of the assessment by means of providing a method of synthetic analysis. Therefore, for systematical management of multidisciplinary data in seawater intrusion problem, we have developed a database management system and 3-D visualization interface based on geographic information system in this, study. All geophysical survey, well logging, hydrochemical, as well as drilling, data are classified as attribute data using Microsoft Access, and joined with spatial information based on ArcView. The database management system and 3-D visualization interface to handle these data, also, developed using the script language of ArcView. We think the development of database and 3-D visualization system will improve the efficiency of data management, user-friendliness of data access, and accuracy of data analysis.

• Economic and Environmental Geology
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• v.49 no.1
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• pp.43-52
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• 2016

The essential role of the Division of Earth Sciences(EAR) in the Directorate of Geoscience(GEO) of National Science Foundation of America(NSF) is to support basic research aimed at acquiring fundamental knowledge of the Earth system that can be directly applied to the United States' strategic needs. The 2011 Committee on New Research Opportunities in the Earth Sciences(NROES) of the National Academy of Sciences(NAS) identified specific areas of the basic earth science research scope of the EAR that were poised for rapid progress during the next decade. Quantified by interdisciplinary approaches, the Committee highlighted the following topics relating to the EAR Deep Earth Processes and Surface Earth Processes sections: (1) the early Earth; (2) thermochemical internal dynamics and volatile distribution; (3) faulting and deformation processes; (4) interactions among climate, the Earth surface processes, tectonics, and deep Earth processes; (5) co-evolution of life, environment, and climate; (6) coupled hydrogeomorphic-ecosystem response to natural and anthropogenic change; and (7) interactions of biogeochemical and water cycles in terrestrial environments. We also promote future research challenges such as the critical zone studies. In order to promote more active such a huge future research challenges, additional research support policies are needed.

• 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.

• The Journal of Engineering Geology
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• v.34 no.3
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• pp.429-445
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• 2024

The Journal of Engineering Geology (JEG), a leading academic journal in the field of engineering geology in South Korea, was first published in 1991 and has since been publishing academic papers and research findings. While several literature reviews have been undertaken on specific research areas in recent decades, comprehensive reviews focusing on JEG have been relatively limited. To address this gap, this study applied the latent Dirichlet allocation (LDA) model to analyze the main research topics and trends, and undertook network analysis to identify relationships between topics over different periods. Results for the LDA indicate seven key research topics categorized into three trends: Classic, Emerging and Stable topics. Classic topics include 'Geophysics' and 'Structural geology', which were major subjects in the early years, with their focus shifting to other areas over time. Emerging topics such as 'Hydrogeology' and 'Geohazards' have gained prominence in recent years. Stable topics including 'Geotechnical structures', 'Geomechanics', and 'Environmental geology' have maintained consistent research interest. Network analysis revealed that Structural geology was the central topic prior to 2008, while Geotechnical structures became the focal point of research after 2008, with a shift in research focus. The results of this study contribute to our understanding of research trends and the development of JEG, providing insights for the setting of future research directions.

• Economic and Environmental Geology
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• v.54 no.3
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• pp.353-364
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• 2021

Since the mid-twentieth century, geology has gradually evolved as an interdisciplinary context in South Korea. The journal of Economic and Environmental Geology (EEG) has a long history of over 52 years and published interdisciplinary articles based on geology. In this study, we performed a literature review using topic modeling based on Latent Dirichlet Allocation (LDA), an unsupervised machine learning model, to identify geological topics, historical trends (classic topics and emerging topics), and association by analyzing titles, keywords, and abstracts of 2,571 publications in EEG during 1968-2020. The results showed that 8 topics ('petrology and geochemistry', 'hydrology and hydrogeology', 'economic geology', 'volcanology', 'soil contaminant and remediation', 'general and structural geology', 'geophysics and geophysical exploration', and 'clay mineral') were identified in the EEG. Before 1994, classic topics ('economic geology', 'volcanology', and 'general and structure geology') were dominant research trends. After 1994, emerging topics ('hydrology and hydrogeology', 'soil contaminant and remediation', 'clay mineral') have arisen, and its portion has gradually increased. The result of association analysis showed that EEG tends to be more comprehensive based on 'economic geology'. Our results provide understanding of how geological research topics branch out and merge with other fields using a useful literature review tool for geological research in South Korea.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.435-450
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• 2022

In step-by-step site selection for geological disposal of high-level radioactive waste, parameters necessary for site selection will be acquired through deep drilling surveys from the basic survey stage. Unlike site investigations of rock mass structures such as tunnels and underground oil storage facilities, those related to the geological disposal of high-level radioactive waste are not only conducted in relatively deep depths, but also require a high level of quality control. In this report, based on the 750 m depth drilling experience conducted to acquire the parameters necessary for deep geological disposal, the methodology for deep drilling and the geology, geophysics, geochemistry, hydrogeology and rock mechanics obtained before, during, and after deep drilling are discussed. The procedures for multidisciplinary geoscientific investigations were briefly described. Regarding in-situ stress, one of the key evaluation parameter in the field of rock engineering, foreign and domestic cases related to the geological disposal of high-level radioactive waste were presented, and variations with depth were presented, and matters to be considered or agonized in acquiring evaluation parameters were mentioned.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.302-309
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• 2008

ERT imaging, especially 3-D method, is a very powerful means to obtain a very high resolution image of the subsurface for geotechnical or hydrogeological problems. In this paper, we introduce two examples of successful case histories, where the imaging targets were three-dimensional. First example is the case of 3-D fracture imaging for hydrogeologic application. In this example, the borehole deviation was a critical problem in the ERT imaging and we could obtain real 3-D attitude of fracture system by including the borehole deviation in the inversion. In the second case, we did field experiment to image the empty tunnel with the size of $2m{\times}2m$ and the target was very clearly imaged in 3-D space. In these examples, we could show that 3-D ERT imaging is a very powerful tool for the 3-D subsurface imaging and the method can provide enhanced imaging capabilities especially for the 3-D targets such as fractures and cavities or tunnel.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.4
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• pp.305-311
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• 2012

Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper focused on how rock's different geological conditions, such as topography, soils, rock types, structural geology, and geological events, influence the functions of the geological repository. In the context, the site selection criteria of various countries were analyzed with respect to the geological conditions. Each country established the criteria based on its important geological backgrounds. For example, it was necessary for Sweden to take into account the effect of ice age on the land uplift and sea level change, whereas Japan defined seismic activity and volcanism as the main siting factors of the geological repository. Therefore, the results of the paper seems to be helpful in preparing the siting criteria of geological repository in Korea.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.737-760
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• 2022

For the geological disposal of high-level radioactive wastes (HLW), an understanding of deep subsurface environment is essential through geological, hydrogeological, geochemical, and geotechnical investigations. Although South Korea plans the geological disposal of HLW, only a few studies have been conducted for characterizing the geochemistry of deep subsurface environment. To guide the hydrogeochemical research for selecting suitable repository sites, this study overviewed the status and trends in hydrogeochemical characterization of deep groundwater for the deep geological disposal of HLW in developed countries. As a result of examining the selection process of geological disposal sites in 8 countries including USA, Canada, Finland, Sweden, France, Japan, Germany, and Switzerland, the following geochemical parameters were needed for the geochemical characterization of deep subsurface environment: major and minor elements and isotopes (e.g., ³⁴S and ¹⁸O of SO₄^2-, ¹³C and ¹⁴C of DIC, ²H and ¹⁸O of water) of both groundwater and pore water (in aquitard), fracture-filling minerals, organic materials, colloids, and oxidation-reduction indicators (e.g., Eh, Fe²⁺/Fe³⁺, H₂S/SO₄^2-, NH₄⁺/NO₃^-). A suitable repository was selected based on the integrated interpretation of these geochemical data from deep subsurface. In South Korea, hydrochemical types and evolutionary patterns of deep groundwater were identified using artificial neural networks (e.g., Self-Organizing Map), and the impact of shallow groundwater mixing was evaluated based on multivariate statistics (e.g., M3 modeling). The relationship between fracture-filling minerals and groundwater chemistry also has been investigated through a reaction-path modeling. However, these previous studies in South Korea had been conducted without some important geochemical data including isotopes, oxidationreduction indicators and DOC, mainly due to the lack of available data. Therefore, a detailed geochemical investigation is required over the country to collect these hydrochemical data to select a geological disposal site based on scientific evidence.