Nam Chil Woo

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• Doctor of Philosophy
• Professor(Full) at Yonsei University

This study investigated the effects of groundwater–surface water (GW–SW) interactions on the fate and transport of arsenic (As) following rainfall events and subsequent water-table changes in GW–SW mixing zones, comprising the riparian and hyporheic zones, near an abandoned gold mine. During the dry and wet periods, stream conditions changed from f...

Seawater intrusion (SWI) is a critical issue for coastal aquifers, especially in islands where groundwater is the sole source of water supply. The objective of this study was to develop a straightforward approach to evaluating groundwater vulnerability to SWI, using a statistical method with spatial analyses applied to the four basins of Jeju volca...

This study investigated the spatiotemporal variation of arsenic (As) distribution, species and its behaviour in the aquatic environment changed by extended dry and heavy rainfall periods in the area adjacent an abandoned gold mine, South Korea. As appears to be transported from the mine wastes to Guryong stream through groundwater baseflow and leac...

Groundwater is the sole source of water for about 670,000 residents of Jeju Island, which is a volcanic Korean island. Since the 1990s, nitrate contamination of groundwater has emerged as a major environmental issue. To ensure the sustainability of water resources, this study aimed to develop a vulnerability model for nitrate contamination as a pre...

Although there is skepticism about the likelihood of predictive success, research on the prediction of an earthquake through precursory changes in natural parameters, including groundwater, has continued for decades. One of the promising precursors is the changes in groundwater, i.e., the level and composition of groundwater, and the monitoring net...

Groundwater is the sole water supply source on Jeju volcanic island in Korea and increasing levels of nitrate contamination have raised serious public concerns. This study was objected to understand the nitrate contamination mechanisms of the coastal groundwater overlain by a low-permeability layer in the western part of the island. The 2-yrs of qu...

The National Groundwater Monitoring Network (NGMN) in South Korea has been implemented in alluvial/ bedrock aquifers for efficient management of groundwater resources. In this study, aquifer types were reclassified with unconfined and confined aquifers based on water-level fluctuation and water quality characteristics. Principal component analysis...

An Mw 5.5 earthquake occurred in Pohang, South Korea on November 15, 2017, resulting in a great impact on society. Despite a lot of controversy about the cause of the earthquake in relation to the enhanced geothermal system (EGS), the location of earthquakerelated active faults is poorly known. Here, we first report the results of the geochemical a...

Significant variation in the precipitation events caused by global climate change has made it difficult to manage water resources due to the increased frequency of unexpected droughts and floods. Under these conditions, groundwater is needed to ensure a sustainable water supply; thus, estimates of precipitation recharge are essential. In this study...

An effective method, involving time and frequency domains was developed to interpret seismic precursors by comparing groundwater-level fluctuations recorded immediately and long before the occurrence of a known earthquake. The proposed method, consisting of the pre-processing (3-point filtering, band-pass filtering, and spectrum analysis) and post-...

This study was objected to assess active changes in hydrochemistry of coastal groundwater through the construction of underground low- and intermediate-level radioactive waste (LILRW) disposal facility. Groundwater monitoring data from the construction stage of the facility beginning in 2010 to the operation stage in 2017 revealed seawater intrusio...

Water level and hydrochemical parameters from groundwater monitoring wells can be effectively used for interpreting changes in the groundwater system when aquifers are appropriately characterized. Groundwater levels in six paired monitoring wells of alluvial and sedimentary bedrock aquifers in the Gyeongju area, southeastern South Korea were analyz...

In this paper, we studied one of the largest coal mines in Mongolia, the Baganuur Coal Mine, in terms of environmental sustainability related to mining practices, with a focus on discharged water and waste sediments. The present quality and potential for future pollution were assessed. Based on World Health Organization and Mongolian guidelines, gr...

Hydrograph analysis provides very important information to make decisions for achieving a sustainable urban watershed, especially for urban streams sustained by stream flow augmentation activities. However, it can be complicated by human activities to control flood. The purpose of this study was to understand the hydrological features of an urban s...

The sustainability of rural areas depends on the availability of water resources. The Mangyeong River Basin (MRB) in Korea faces a water supply shortage for agriculture and industry. Based on 11-year (2005–2015) precipitation and groundwater monitoring data, groundwater sustainability was evaluated in terms of natural and man-made factors and their...

This study analyzed groundwater level changes in a monitoring well located in Korea’s Yangsan fault zone, induced by local (Gyeongju and Pohang) earthquakes in Korea and offshore earthquakes around the world. Among offshore earthquakes, the MW 7.3 Honshu earthquake changed raw groundwater level of a maximum of 10.3 cm. The groundwater level data we...

The purpose of this study was to understand the unique and complicated feature of urban stream receiving various inflows. The Yangjae stream, the second tier of the Han River, runs through the southern parts of Seoul, Korea and its middle part flows on the boundary of Seoul where land use is actively changing. Stream flow was greatly influenced by...

Fine sediments can act as a source or a sink for hazadous metals in aquous environments according to its condition. Especially sediments in urban stream were affected by various anthropogenic activities like input of road deposited sediments by initial rainfall or discharge from waste water treatment facility. The purpose of this study was to evalu...

Despite some skeptical views on the possibility of earthquake prediction, observation and evaluation of precursory changes have been continued throughout the world. In Korea, the public concern on the earthquake prediction has been increased after 2016 ML5.8 and 2017 ML5.4 earthquakes occurred in Gyeongju and Pohang, the southeastern part in Korea,...

Ulaanbaatar (UB), the capital of Mongolia, is one of the fastest-growing cities in the developing world. Due to increasing demand driven by rapid population and industrial growth, sustainable water resource management is required. Therefore, we investigated sustainability in UB from the perspective of water quality. During five sampling campaigns,...

As one of the important elements of controlling the redox system within the hyporheic and hypolentic zone, sulfur is involved in a series of complex biogeochemical processes such as carbon cycle, water acidification, formation of iron and manganese minerals, redox processes of trace metal elements and a series of important ecological processes. Pre...

This study monitored four geothermal groundwater (TW) wells (Suanbo, Yuseong, Deoksan, and Seokmodo), four carbonated groundwater (CW) springs (Chojeong, Bugang, Shin, and Bangadari) and shallow groundwater (GW) in order to interpret the carbonating process from the seepage of CO2. In a bid to figure out the carbonated reservoir where CO2 mixing oc...

A geological repository for low and intermediate radioactive waste (bottom at −130 m a.s.l.) was constructed from 2008 to 2014 in the southeastern coastal area in Korea. This research aimed to evaluate the hydrogeochemistry in this area during the construction period and to determine the characteristics that should be monitored during the operation...

The spatial and temporal distribution of redox zones in an aquifer is important when designing groundwater supply systems. Redox zonation can have direct or indirect control of the biological and chemical reactions and mobility of pollutants. In this study, redox conditions are characterized by interpreting the hydrogeological conditions and water...

When groundwater drought occurs, baseflow discharges to surface-water bodies will be reduced and then domestic and agricultural water usage becomes at risk of insufficient supply. Thus, in this study, several methods for groundwater drought assessment were tested with long-term monitoring water-level data in the study area to preserve groundwater s...

Stable carbon isotope ratio of carbon dioxide (δ13CCO2) is used as an important indicator in the researches for global climate change and carbon capture and sequestration technology. The δ13C value has been usually analyzed with Isotope Ratio Mass Spectrometer (IRMS). Recently, the use of Laser Absorption Spectrometry (LAS) is increasing because of...

To prevent the damages from earthquakes, various researches have been conducted around the world focusing on earthquake prediction and forecasting for several decades. Among various precursory phenomena, changes in groundwater level and quality are considered to be reliable for estimating the time of earthquake occurrence and its magnitude. In effe...

This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA), and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-lev...

The seismicity in the Korean Peninsula has increased since the 2011 Mw9.0 Tohoku-Oki megathrust earthquake. Two strike-slip earthquakes with magnitudes of ML5.1 and 5.8 occurred in the southeastern Korean Peninsula on September 12, 2016. The two events occurred within 48 minutes. The ML5.8 earthquake was the largest event in the Korean Peninsula si...

A baseline hydrochemistry of the above zone aquifer was examined for the potential of CO2 early detection monitoring. Among the major ionic components and stable isotope ratios of oxygen, hydrogen, and carbon, components with a relative standard deviation (RSD) of <10 % for the seasonal variation were selected as relatively stable. These components...

Dimethylmonothioarsinic acid (DMMTAV) is a highly toxic, thiolated analogue of dimethylarsinic acid (DMAV). In comparison, a further thiolated analogue, dimethyldithioarsinic acid (DMDTAV), and DMAV both exhibit lower toxicity. To understand the environmental conditions responsible for forming DMMTAV, the kinetics of DMAV thiolation are examined. T...

Chronic exposure even to extremely low specific radioactivity of natural uranium in groundwater results in kidney problems and potential toxicity in bones. This study was conducted to assess the potential health risk via intake of the groundwater containing uranium, based on the determination of the uranium occurrence in groundwater. The groundwate...

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 ox...

Sulfuric acid, a highly corrosive substance with a high risk of accidental spills, is important worldwide as a raw material in chemical production. This research aims to develop the best analytical method to determine sulfur contents from the accidental spill sites of sulfuric acid. Wavelength dispersive X-ray fluorescence (WDXRF) spectrometry was...

This study tests the potential of detecting small-magnitude earthquakes (~M3.0) and their precursors using a long-term groundwater-monitoring database. In groundwater records from April to June 2012, abnormal changes in water level, temperature, and electrical conductivity were identified in the bedrock monitoring wells of the Gimcheon-Jijwa, Gangj...

Groundwater is important for domestic, industrial, and agricultural uses in Ho Chi Minh City, Vietnam. As the city has developed in a coastal environment, the issue of the fresh water supply must be solved for continuous development. The aim of this study was to quantitatively estimate the risk of groundwater salinization in the Ho Chi Minh area du...

As one of the largest copper–molybdenum (Cu–Mo) mines in the world, the Erdenet Mine in Mongolia has been active since 1978 and is expected to continue operations for at least another 30 years. In this study, the potential impacts of mining activities on the soil and water environments have been evaluated. Water samples showed high concentrations o...

This study was objected to evaluate the potential impact on the groundwater environment of the coal bottom ash used as fill materials on the land surface. From four coal-fired power plants, bottom-ashes were collected and analyzed through sequential extraction and column leaching tests following the meteoric water mobility procedure. The column tes...

To establish an aging management plan considering seawater influx and changes in groundwater within nuclear power plant sites, the characteristics of groundwater flow must be understood. This study investigated the characteristics of groundwater flow within the site and analyzed groundwater level recorded by monitoring wells to evaluate groundwater...

Changes in groundwater level have been recognized by the earthquakes at various epicentral distances. The M9 Sumatra earthquake resulted in changes in the groundwater level, electrical conductivity, and temperature in monitoring wells on Jeju Island, South Korea. In regions of different groundwater type (basal, lower parabasal, upper parabasal, and...

Global climate changes affect the local hydrologic cycle, and subsequently, require changes in water resource management strategies of Korea. Variations in precipitation and urbanization have adverse effects on the reasonable and efficient utilization of groundwater resources. Groundwater management strategies of Korea have been implemented based o...

An exploratory investigation was conducted to assess the present conditions and evaluate the potential impacts of mining activities on soil and water environments at the Shivee-Ovoo coalmine area in Mongolia. Water quality analysis was conducted on samples from mine dewatering boreholes, a tailings dam, and drinking water sources around the mine ar...

Effects of climate change on groundwater system requires understanding the groundwater system in temporal and spatial scales through the long-term monitoring. In this study, the spatio-temporal variations of groundwater were analyzed through the continuous observation of water level, electrical conductivity (EC) and water temperature with automatic...

The M9.0 earthquake occurred at 05:46:23 UTC on March 11, 2011 off the coast of Tohoku, Japan, causing devastating tsunami-driven disasters along coastal areas. The influence of the Tohoku earthquake was detected at 46 of 320 monitoring wells of the Korea National Groundwater Monitoring Network (NGMN) in terms of changes in water level, temperature...

Selection of appropriate liner type would be the most important factor to prevent groundwater contamination by leachate from waste management site. This report introduces the IWEM (Industrial Waste Management Evaluation Model) developed by US EPA to evaluate the potential pollution of groundwater under the waste management unit and to suggest an ap...

This study was carried out for analyzing the impact of the major construction activity on the seawater-intrusion at the coastal aquifer. Study site is located at the southeastern part of Korean peninsula. A total of eight monitoring wells were installed and has been monitored every 3 months for groundwater level and quality changes from May 2010 to...

Mining sector is one of most rapidly developing industries in Mongolia for the last several decades. However, environmental monitoring and protection measures have been left out. An exploratory investigation was conducted to evaluate potential impacts of the mining activities on the soil and water environment at the Shivee-Ovoo surface coal mine. W...

In Korea, the National Groundwater Monitoring Network(NGMN), consisted of 327 monitoring stations, has been established since 1995, and water level fluctuation, temperature and electrical conductivity have been measured by every hour to every six hours. In addition, along the KoFlux program, we have monitored a small catchment, the Gwangneung catch...

By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of road...

In Korea, the National Groundwater Monitoring Network (NGMN), consisted of a total of 327 stations around the country up to date, has been established and operated to monitor the background level and quality of ground water since 1995. From some of the monitoring wells, we identified abnormal changes in groundwater due to earthquakes. Then, this pr...

Groundwater monitoring data from the National Groundwater Monitoring Stations, a total of 320 stations, were analyzed to identify the response of water level and quality to the Odaesan earthquake (M4.9) occurred in January 2007. Among the total of eight stations responded to the earthquake, five wells showed water-level decline, and in three wells,...

The nitrate of groundwater in the Gimpo agricultural area, South Korea, was characterized by means of nitrate concentration, nitrogen-isotope analysis, and the risk assessment of nitrogen. The groundwaters belonging to Ca–(Cl + NO3) and Na–(Cl + NO3) types displayed a higher average NO3− concentration (79.4 mg/L), exceeding the Korean drinking wate...

This study was objected to provide suggestions for best management practices to restore the cultural and historical values of the wells in Palaces as well as their water qualities. Water resources in the five Palaces in Seoul Metropolitan, including Gyeongbokgung, Changdeokgung, Changgyeonggung, Jongmyo Shrine, and Deoksugung, were surveyed for the...

This study was carried out for estimating the seawater intrusion at the disturbed aquifer by a large scale construction when building a power plant in a coastal region, located in southeastern part of the Korean peninsula. Groundwater sampling and vertical profiling of electrical conductivity(EC) for 8 monitoring wells were carried. EC profiling re...

The effect of global climate changes has risen as a significant issue in Korea. Facing shortage of water supply to demand, we need to understand the effects on water resources, both surface and ground waters. Climate change will be reflected to groundwater, a component of the water cycle, although the response would be slow and gradual relatively t...

Water level, water temperature and electric conductivity (EC) has been monitored by 6-hr interval at the National Groundwater Monitoring System (NGMS) of Korea that consists of a total of 320 stations around the country. This study covers the difference in responses of groundwater to local and distant earthquake which occurred seven days apart in J...

As a preliminary survey to improve efficiency of well-based permeable reactive barrier system for groundwater remediation, this site-scale study was carried to identify the flowpaths and controlling factors of plume at a remediation site in Suwon City, Korea. A total of 22 monitoring wells were installed as a grid system in the square area by 1-m i...

This study characterizes aquifer system and hydrogeologic property in the western half of Jeju Island where wells were drilled for regional water supply in three sub-areas (northwestern, western, and southwestern sub-areas). The aquifer system of the northwestern sub-area is largely composed of upper high-permeability layer, upper low-permeability...

Since 2006, groundwater levels have been monitored in a remote and preserved research area in Korea to understand the influence of hydrologic stresses on groundwater and its resultant effect on water-level changes. Two nested monitoring wells, about 2 km apart, accommodate three piezometers at depths of 10, 50 and 100 m, respectively. Multi-probes...

A controlled-release technique using potassium permanganate (KMnO4) has been recently developed as a long-term and semi-passive remediation scheme for dilute groundwater plumes of chlorinated solvents such as trichloroethylene (TCE) and perchloroethylene. Batch experiments were performed to evaluate TCE removal efficiencies of a low concentration o...

The objectives of this study were to quantitatively estimate the distribution of arsenic with its speciation and to identify potential pathways for transformation of arsenic species from samples of water, sediments, and plants in the ecosystem affected by the Cheongog Spring, where As(V) concentration reached levels up to 0.270 mg L(-1). After flow...

Closing energy and water budgets in terrestrial ecosystems still remains as a challenge, particularly for those with heterogeneous vegetation in complex terrains. This paper presents an attempt to quantitatively estimate parts of water-level fluctuation due to evapotranspiration (ET) and earth tides, and their seasonality at the Gwangneung forest c...

A well-type permeable barrier system containing controlled-release molasses as a reactive material to promote the indigenous denitrifying activity (termed CRM system hereafter) has been developed for controlling nitrate plume in groundwater. To control the release of molasses as an extra carbon and energy source, CRM rod (OD x L = 4 cm x 30 cm) was...

A well-based, reactive barrier system using controlled-release potassium permanganate (CRP system) was recently developed as a long-term treatment option for dilute plumes of chlorinated solvents in groundwater. In this study, we performed large-scale (L x W x D = 8 m x 4 m x 2 m) flow-tank experiments to examine remedial efficacy of the CRP system...

The applicability of a well-type autotrophic sulfur-oxidizing reactive barrier (L W D = ) as a long-term treatment option for nitrate removal in groundwater was evaluated. Pilot-scale (L W D = ) flow-tank experiments were conducted to examine remedial efficacy of the well-type reactive barrier. A total of 80 kg sulfur granules as an electron donor...

This study was objected to identify the effect on water quality and contamination by non-agricultural facilities in 'A' reservoir watershed located in OO city, Kyounggi-do, Korea. Ground- and stream water samples showed (Na+K)-Cl, Ca(Cl, SO) and Ca-Cl type in an illegally discharging area of sewage and a densely industrial area indicating water con...

To supplement conventional geophysical log data, this study presents temporal variations in electrical conductivity (EC) and temperature with depth in a multilayered coastal aquifer, on the eastern part of Jeju Island, Korea. One-month time-series data obtained at eight points from a multi-depth monitoring system showed that semidiurnal and semimon...

Release and spreading of permanganate (MnO(4)(-)) in the well-based controlled-release potassium permanganate (KMnO(4)) barrier system (CRP system) was investigated by conducting column release tests, model simulations, soil oxidant demand (SOD) analyses, and pilot-scale flow-tank experiments. A large flow tank (L x W x D=8m x 4m x 3m) was construc...

Periodic fluctuation of water levels were analyzed for their causes and effects on groundwater movement. Groundwater levels were monitored from two shallow monitoring wells, G1 and G4, located at a headwater catchment in the Gwangneung Ecohydrological Research Site using pressure transducers with automatic data-loggers by five-minute interval from...

Hydrogeochemistry of groundwater was studied in order to identify the influence of cow manure, distributed to a farmland as organic fertilizer, on nitrate concentrations in shallow groundwater and its spatio-temporal variations. From monitoring wells, water levels were measured using automatic data loggers, and water samples collected and analyzed...

In the Gwangneung forest, a Korean National Arboretum, fluxes of energy, water and CO2 have been monitored continuously over the forest catchment as a part of HydroKorea project. Using variograms, characteristic time scales of hydrologic parameters including precipitation, stream discharge, soil moisture and groundwater levels in response to the ra...

For effective assessment and management of water resources, it is important to understand and quantify each component of the hydrologic cycle. A careful and detailed analysis of spatio-temporal variations in water levels in aquifers could reveal useful information on the groundwater system. This study is objected to understand the reasons and mecha...

This study was initiated to assess the potentials for nitrate contamination of water supply from the up-gradient agricultural areas. The study site is a small farmland, located in the upper stream of Gwang-gyo reservoir, a water supply source for the Suwon City, Korea. Livestock manure has been used in many of small farmlands as a natural fertilize...

In this study, a soil monitoring system for a hillslope with steep relief and shallow soil depth was designed and installed to represent efficiently the spatial and temporal features of soil moisture. The study was conducted on a mountainous hillslope of the Sulmachun catchment (northeastern South Korea). The positions of soil moisture sensors were...

This study was undertaken to ascertain optimal methods of sampling, preserving, separating, and analyzing arsenic species in potentially contaminated waters. Arsenic species are readily transformed in nature by slight changes in conditions. Each species has a different toxicity and mobility. The conventional field sampling method using filters of 0...

Groundwater recharge rates were estimated and compared in a headwater catchment at the Gwangneung Supersite using three different methods: water-table fluctuation (WTF), mass balance, and hydrograph separation techniques. Data were obtained during the rainy season from June to September 2005. Two different WTF methods estimated the groundwater rech...

KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inte...

A two-dimensional semi-analytical solution to analyse stream–aquifer interactions in a coastal aquifer where groundwater level responds to tidal effects is presented. The conceptual model considered is a two-dimensional subsurface system with stream and coastline boundaries at right angles. The dimensional and non-dimensional boundary value problem...

Recently, the branch-out of foreign companies into domestic markets through M&A and the opened followed by the Free Trade Agreement(FTA) with America have made the environmental site assessments of specific site more necessary. In this study, through case study of conducting actual environmental site assessment by use of a toolbox approach at a lar...

We conducted various field studies at the seawater intrusion monitoring wells located in the eastern part of Jeju Island, Korea, to observe the tidal effect on groundwater–seawater flow in the coastal aquifer. Studies included monitoring the fluctuations of groundwater and tide levels, electrical and temperature logging, and 2-D heat-pulse flowmete...

The KoFlux program is dedicated to understanding the fluxes of energy and matter, water resource management, and net ecosystem production in key ecosystems of Monsoon Asia. Under the framework of AsiaFlux, it is a joint effort with determined, comprehensive international strategies to bring Asia’s key ecosystems under observation. Built upon the au...

Effects of a rainfall event (July 28, 2005) on the hydrochemical characteristics of the Jungrang river, the biggest tributary of the Han river, was investigated. Significant spatial variations in the hydrochemical characteristics were observed. At JR2 location, concentrations of T-N and T-P were relatively low indicating occurrence of active oxidat...

Distribution and speciation of arsenic in water resources was investigated in the Ulsan mine area. In 62% of groundwater samples from the mine area, total As concentrations exceeded 0.05 mg/l, the Korean Drinking Water Standard. As(V) was the major type in groundwater with minor As(III). Arsenic species appeared to be in transition stages following...

The importance of arsenic detection in terms of different chemical species is becoming nowadays environmental concern. The analytical technique for true separation of different arsenic species has been challenging in many environmental samples. Achieving correct analytical results and resolving the lowest detection limit of each species is also des...

The purpose of this study is to understand the distribution of arsenic species in the hydrologic system and to compare sampling and analyzing methods. A well-known and historical iron mine, located in the suburb of Ulsan in Korea, has been identified as the source of environmental problems because of high arsenic contents. This mine formed as a cal...

Data from 122 pumping tests were obtained from 100 boreholes in granites, volcanic rocks, metamorphic rocks, and Cretaceous and Tertiary sedimentary rocks, and then were analyzed using AQTESOLV. Results from 86 of the 122 tests () have an analytical solution corresponding to Theis (1935), Cooper-Jacob (1946), Papadopulos-Cooper (1967), Hantush (196...

The seasonal variation of water quality was studied in the Hwabongcheon. It runs though a small catchment where shallow groundwater was contaminated with NO3-N by intensive livestock facilities. A direct inflow of animal waste and incoming of contaminated groundwater affected its water quality. In the dry season, an important factor of water qualit...

A two-dimensional semi-analytical solution is presented to analyze the stream-aquifer interaction in a coastal aquifer where groundwater responds to tidal effect. The conceptual model considered in this study is a two-dimensional subsurface system bounded by stream and coastline in right angle. The stream is semi-infinitely long in longitudinal ext...

Using water-table monitoring data from the National Groundwater Monitoring Network in Korea, groundwater hydrographs were classified into five typical groups. Then, to estimate groundwater recharge, a modified water-table fluctuation (WTF) method was developed from the relation between the cumulative WTF and corresponding precipitation records. App...

The purpose of this study is to evaluate ground water quality and to identify the temporal and spatial variation of ground water contamination at Hanlim area, Jeju Island. Ground- and spring- water samples were collected in August and November, 2002, and April, 2003. And investigation for analysis of stable isotopes, delta 18O and delta 2H, was con...

The ulsan mine, which is known as an important producer of iron, tungsten and arsenic ores in southeastern Korea, is located in Gyeongsangnam Province. This mine is of calcareous skarn deposit represented by ore pipe consisting mainly of magnetite with minor scheelite, sulphides, sulphosalts, arsenides and sulpharsenides (Choi et.al. 1993). A total...