• 자원환경지질
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• 제31권3호
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• pp.265-271
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• 1998

In the hydrologic and hydrochemical studies of natural waters, oxygen and hydrogen isotope compositions of waters are very important to elucidate the origin and circulation pattern of water in the hydrologic system. The hydrogen isotope analysis of waters usually has been undertaken through the reduction of water to form hydrogen gas using pure metals (in general, zinc and uranium). In 1996, a new apparatus (H/Device) was developed to prepare the water samples (by the reduction with Cr metal) without some intrinsic problems that may yield incorrect and/or inaccurate data, and was installed at 1997 in the Center for Mineral Resources Research (CMR) in Korea University. However, the optimistic conditions of preparation and analysis of samples has not been established. In this paper, we introduce the efficiency of H/Device to obtain accurate hydrogen isotope values of water, and discuss both the optimum conditions including the effective reduction time and the probable mixing (memory) effect between successive samples. We obtained large amounts of a laboratory working standard (KUW; Korea University Water) with the average ${\delta}D_{SMOW}$ value of $-42.1{\pm}1.0$‰ $(1{\sigma})$.

• Environmental Engineering Research
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• 제24권2호
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• pp.279-288
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• 2019

To obtain insightful knowledge of geochemical process controlling fluoride enrichment in groundwater of the villages near Shilabati river bank, West Bengal, India, multivariate statistical techniques were applied to a subgroup of the dataset generated from major ion analysis of groundwater samples. Water quality analysis of major ion chemistry revealed elevated levels of fluoride concentration in groundwater. Factor analysis (FA) of fifteen hydrochemical parameters demonstrated that fluoride occurrence was due to the weathering and dissolution of fluoride-bearing minerals in the aquifer. A strong positive loading (> 0.75) of fluoride with pH and bicarbonate for FA indicates an alkaline dominated environment responsible for leaching of fluoride from the source material. Mineralogical analysis of soli sediment exhibits the presence of fluoride-bearing minerals in underground geology. Hierarchical cluster analysis (HCA) was carried out to isolate the sampling sites according to groundwater quality. With HCA the sampling sites were isolated into three clusters. The occurrence of abundant fluoride in the higher elevated area of the observed three different clusters revealed that there was more contact opportunity of recharging water with the minerals present in the aquifer during infiltration through the vadose zone.

• 한국지형학회지
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• 제23권1호
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• pp.77-85
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• 2016

To understand the difference of runoff discharge processes between Gwangneung deciduous and coniferous forest catchments, we collected hydrological data (e.g., precipitation, soil moisture, runoff discharge) and conducted hydrochemical analyses in the deciduous and coniferous forest catchments in Gwangneung National Arboretum in the northwest part of South Korea. Based on the end-member mixing analysis of the three storm events during the summer monsoon in 2005, the hillslope runoff in the deciduous forest catchment was higher 20% than the coniferousforest catchment during the firststorm event. Howerver, hillslope runoff increased from the second storm event in the coniferous catchment. We conclude that low soil water contents and topographical gradient characteristics highly influence runoff in the coniferous forest catchment during the first storm events. In general, coniferous forests are shown high interception loss and low soil moisture compared to the deciduous forests. It may also be more likely to be a reduction in soil porosity development when artificial coniferous forests reduced soil biodiversity. The forest soil porosity is an important indicator to determine the water recharge of the forest. Therefore, in order to secure the water resources, it should be managed coniferous forests for improving soil biodiversity and porosity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권2호
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• pp.87-98
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• 2022

This study aims to prepare a technical protocol for identifying the source of nitrate in water using nitrogen (δ¹⁵N) and oxygen (δ¹⁸O) stable isotope ratios. The technical processes for nitrate sources identification are composed of site investigation, sample collection and analysis, isotope analysis, source identification using isotope characteristics, and source apportionment for multiple potential sources with the Bayesian isotope mixing model. Characteristics of various nitrate potential sources are reviewed, and their typical ranges of δ¹⁵N and δ¹⁸O are comparatively analyzed and summarized. This study also summarizes the current knowledge on the dual-isotope approach and how to correlate the field-relevant information such as land use and hydrochemical data to the nitrate source identification.

• 한국지구과학회지
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• 제43권4호
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• pp.481-489
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• 2022

Various types of karst topographies are found worldwide. Owing to their global distribution, karst areas have been extensively studied by scientists who investigate new discoveries by linking the characteristics of karst topographies with their own research fields. However, there have been only a few studies on karsts in the Republic of Korea, and little research exists on their hydrogeology. Fragmentary studies have been conducted on the hydrochemical characteristics of groundwater in limestone areas, the causes of high arsenic concentrations in groundwater, and the hydraulic conductivity of limestone areas. Research on hydrogeological characterization and flow mechanisms in these areas has only began recently. Identification and the proper management of available groundwater resources in karst (limestone) areas is essential as their unique geological characteristics render it difficult to construct reservoirs or dams at appropriate scales. We have reviewed prior work on karsts in the Republic of Korea to provide information that supports water resource security in the karst areas, to improve the understanding of the equitable use of water resources, and to identify the best management practices for groundwater resource resilience improvement.

• 한국지구과학회지
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• 제35권4호
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• pp.225-236
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• 2014

다변량통계기법은 수리지구화학 자료의 분석 및 해석에 많이 이용되어 왔다. 본 연구에서 대응분석과 주성분분석을 동시에 사용하여 인위적인 활동에 의한 지하수의 특징을 살펴보았다. 본 연구의 목적은 NETPATH 프로그램 속의 WATEQ4F를 이용하여 지하수 화학성분의 분화를 계산하고 이를 다변량통계기법을 이용하여 지구화학적인 정보를 추출하는 것이다. 연구지역은 한반도의 남동쪽에 위치한 울산의 LPG 저장시설이다. 본 연구지역에서는 다른 저장시설에서 관찰되는 초염기성의 조성을 가지는 지하수가 관찰되었다. 이러한 인위적인 영향에 의한 높은 pH를 가지는 지하수로 인해 Al의 분화특징과 탄산염의 침전을 유발할 수 있다. 본 연구에서는 연구지역에 지하수에 영향을 주는 두 인위적인 요소(세정작용와 시멘트영향)에 의해서 수리지구화학적인 특징과 상이 어떻게 변하는 가에 초점을 두었다. 이전 연구결과와 두 통계분석을 통해 제시된 결과를 비교하여 지구화학적인 정보를 이용한 주성분분석과 대응분석인 수리지구화학 연구에서 기초연구로 활용될 수 있음을 알 수 있다.

• 지질공학
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• 제26권1호
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• pp.1-13
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• 2016

Groundwater flow paths and groundwater ages at a radioactive waste repository located in a coastal area of South Korea were evaluated using the hydrochemical and hydrogeological characteristics of groundwater, surface water, rain water, and seawater, as well as by numerical modeling. The average groundwater travel time in the top layer of the model, evaluated by numerical modeling and groundwater age (34 years), approximately corresponds to the groundwater age obtained by chlorofluorocarbon (CFC)-12 analysis (26-34 years). The data suggest that the groundwater in wells in the study area originated up-gradient at distances of 140-230 m. Results of CFC analyses, along with seasonal variations in the δ¹⁸O and δD values of groundwater and the relationships between ²²²Rn concentrations and δ¹⁸O values and between ²²²Rn concentrations and δD values, indicate that groundwater recharge occurs in the summer rainy season and discharge occurs in the winter dry season. Additionally, a linear relationship between dissolved SiO₂ concentrations and groundwater ages indicates that natural mineralization is affected by the dilution of groundwater recharge in the rainy summer season.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.499-502
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• 2004

Groundwater chemistry in a coastal region having complex contaminant sources was investigated. Water analysis data for 197 groundwater samples collected from the uniformly distributed sixty-six wells were used. Chemical analysis rand results indicate that groundwaters show wide concentration ranges in major inorganic ions, reflecting complex hydrochemical processes of pollutants. Due to the complexity of groundwater chemistry, Results illustrate that thirty five percent of the wells do not fit for drinking based on nitrate and chloride concentration in the study area. the samples were classified into four groups based on Cl and NO$_3$ concentrations and the processes controlling water chemistry were evaluated based on the reaction stoichiometry. The results explained the importance of mineral weathering, anthropogenic activities (nitrification and oxidation of organic matters), and Cl-salt inputs (seawater, deicer, NaCl, etc.) on groundwater chemistry. It was revealed that mineral dissolution is the major process controlling the water chemistry of the low Cl and NO$_3$ group (Group 1). Groundwaters high in NO$_3$ (Groups 2 and 4) are acidic in nature, and their chemistry is largely influenced by nitrification, oxidation of organic matters and mineral dissolution. In the case of chloride rich waters (Group 3), groundwater chemistry is highly influenced by mineral weathering and seawater intrusion associated with cation-exchange reactions.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.158-159
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• 2005

This study showed that the highest temperature point of the Dongrae thermal spring in Pusan was moved to the north direction of the Dongrae fault as times goes by. The Br concentration(1.5mg/L) in Dongrae thermal waters indicated the influence of 2% seawater mixing. If the simple mixing without hydrochemical reaction occurs between seawater and thermal water, the concentration of Mg will be about 20mg/L. But the low concentration(0.1 mg/L) of Mg, contrary to high concentration(10 mg/L) of surrounding groundwater not affected by thermal water, suggested the thermal water, seawater and rock interactions. The calculation of saturation index(SI) by using the geochemical code of EQ3NR showed that the Mg in thermal groundwater, which was introduced by seawater, was removed by the precipitation of Antigorite (SI: log Q/K =71.753, $Mg_{48}Si_{24}O_{85}(OH)_{62}$) and Tremolite (SI: 8.463, $Ca_2Mg_5Si_8O_{22}(OH)_2$), Talc (SI: 6.409, $Mg_3Si_4O_{10}(OH)_2$), Dolomite (SI: 2.014, $CaMg(CO_3)_2$), Chrysotile (SI: 3.698, $Mg_3Si_2O_5(OH)_4$) in the crack of fault zone. The highest temperature point in the study area will move to north direction and stop in the Jangjun area without the input of seawater.

• 지질공학
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• 제27권4호
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• pp.501-511
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• 2017

이 연구에서는 전라남도 지역의 지하수 170개 소를 대상으로 자연방사성물질인 우라늄, 라돈을 분석하였으며, 지질별로 구분하여 이들의 함량특성을 지구화학적, 통계적으로 고찰하였다. 또한 우라늄과 라돈의 함량을 지질도에 표기하여 이들의 함량분포도를 작성하였다. 우라늄과 라돈의 함량범위는 넓지만 일부 시료를 제외하면 낮은 값을 보인다. 요인분석 결과에 의하면 전남지역의 지하수에서 우라늄과 라돈간의 상관계수는 낮아서, 이 두 성분은 서로 다른 거동특성을 가지는 것으로 판단된다. 서로 거의 무관한 거동특성을 보여주는 이러한 결과는 국내 대부분의 지하수중 우라늄, 라돈 연구결과와도 일치한다. 이들을 제외하면 주요 수질항목들 간에는 높은 상관계수가 나타나는데, 이들은 일반적인 물-암석반응의 결과임을 지시한다.