• Economic and Environmental Geology
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• v.33 no.1
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• pp.51-59
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• 2000

As a part of natural hazard assessment, regional slope stability analysis was conducted using Geoscientific Information System (GIS) in the northern area of Chungju Lake. Selected factors which affect the slope stability in the study area were lithology, soil, density of lineament, groundwater level, dip of slope, aspect of slope, and geological engineering properties. Geological structural domains were determined by collected data of joint orientation from about 200 sites in order to produce a slope instability map. Potential type of failure and its direction could be expected through the domains. And a slope instability map was produced, comparing the representative orientations of the domains with the orientations of the slopes which were made through TIN module in ARC/INFO. Under the consideration of environmental geological characteristics of the study area, rating and weighting of each factor of slope stability analysis were decided and spatial analysis of regional slope stability was couducted through overlaying technique of GIS. The result of areal distribution of slope stability showed that the most unstable area was the area between Mt. Pudae and Mt. Jubong, and the northern area of the railway station, Samtan.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.437-440
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• 2005

서울시는 복개천이었던 청계천을 복원하여 도심지를 통과하는 하천을 만들기 위해 청계천 복원 공사를 수행하고 있다. 청계천 복원 공사 구간을 포함하는 유역에는 서울시 지하철 1, 2, 4, 5, 6호선 등이 통과하고 있으며, 도시 내 비수시설, 하수관거시설 등 자연적인 수문현상에 영향을 주는 인위적인 요소들이 복합적으로 존재하고 있다. 때문에 청계천 복원 공사 후 유역내의 여러 요인들과 공사의 정도에 따라 누수가 발생할 것으로 예상된다. 공사 후 청계천에서의 누수율에 대한 측정은 공사의 성공여부를 결정하고, 향후 지속적인 누수가 예상되는 청계천의 유지 보수에 있어서 매우 중요하다. 특히 청계천의 손실량의 대부분을 차지할 지하로의 누수에 대한 측정은 매우 중요하다. 따라서 누수율을 측정하고, 누수율과 주변 요인들과의 관계를 추정할 수 있는 수문모델링을 수행할 필요성이 있다. 수문모델링은 일회성으로 끝나는 것이 아니라 지속적으로 수행될 필요가 있는데, 그러기 위해서는 청계천 유역에서의 지속적인 수문관련 인문 자연자료를 획득하여 정리할 필요성이 있다. 본 연구에서는 청계천 복원 공사 구간의 유역에 대한 인문 자연자료를 GIS(지리정보시스템)을 이용하여 수치도면과 속성테이블 형태로 데이터베이스화한다. 그럼으로써 청계천 주변 유역에 대한 도시형 수문 모델링 연구에 활용하고, 아울러 공사 후 지속적으로 누수율을 측정하는데 자료를 원활히 제공하여 청계천의 유지 보수에 도움을 줄 수 있는 체계를 마련하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.523-531
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• 2011

Many of the wells which were constructed to use ground water resource are abandoned and not managed efficiently after its use. And a variety of heavy metals and organic compounds are released from the abandoned wells and this can cause ground water pollution. Therefore in this paper implemented to monitor locational information drill holes and underground water sensing information on real time basis using u-GIS environment to combined ubiquitous sensor node and GIS technology to improve these problems. In addition, this system suggests using system by UML 2.0 by analyzing variety requirement of user and between system internal modules interaction and data flow. It provides graphical user interfaces (GUI) to system users to monitor water-well related property information and its managements for each water-well at remote site by variety platform by GIS map and web environment and mobile device based on smart phone.

• Economic and Environmental Geology
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• v.34 no.6
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• pp.595-600
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• 2001

Recently, interests in subsidence hazard have been increased due to the underground construction such as subway construction and managements of abandoned mines. GIS analysis of subsidence hazard has a lot of advantages in handling of spatial data and managing database. For better result of GIS analysis, there are some necessities of modifying previous subsidence theory and model. To take surface profile into account allows the application of complicated topology. Furthermore. for 3-dimensional analysis. two subsidence profile curves that are perpendicular to each other should be considered simultaneously. Through these modifications, the model for subsidence analysis using GIS can be established. With ideal case of cavities and other conditions, GIS analysis was accomplished and meaningful results were produced. More realistic properties of cavity. soil layers, groundwater condition and topology will enable GIS analysis method to produce more reliable result and to widen the area of applications.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.50-63
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• 2018

The rapid urbanization had led to a distortion of natural hydrological cycle system. The change in hydrological cycle structure is causing streamflow depletion, changing the existing use tendency of water resources. To manage such phenomena, a streamflow depletion impact assessment technology to forecast depletion is required. For performing such technology, it is indispensable to build GIS-based spatial data as fundamental data, but there is a shortage of related research. Therefore, this study was conducted to use the use of GIS-based time series spatial data for streamflow depletion assessment. For this study, GIS data over decades of changes on a national scale were constructed, targeting 6 streamflow depletion impact factors (weather, soil depth, forest density, road network, groundwater usage and landuse) and the data were used as the basic data for the operation of continuous hydrologic model. Focusing on these impact factors, the causes for streamflow depletion were analyzed depending on time series. Then, using distributed continuous hydrologic model based DrySAT, annual runoff of each streamflow depletion impact factor was measured and depletion assessment was conducted. As a result, the default value of annual runoff was measured at 977.9mm under the given weather condition without considering other factors. When considering the decrease in soil depth, the increase in forest density, road development, and groundwater usage, along with the change in land use and development, and annual runoff were measured at 1,003.5mm, 942.1mm, 961.9mm, 915.5mm, and 1003.7mm, respectively. The results showed that the major causes of the streaflow depletion were lowered soil depth to decrease the infiltration volume and surface runoff thereby decreasing streamflow; the increased forest density to decrease surface runoff; the increased road network to decrease the sub-surface flow; the increased groundwater use from undiscriminated development to decrease the baseflow; increased impervious areas to increase surface runoff. Also, each standard watershed depending on the grade of depletion was indicated, based on the definition of streamflow depletion and the range of grade. Considering the weather, the decrease in soil depth, the increase in forest density, road development, and groundwater usage, and the change in land use and development, the grade of depletion were 2.1, 2.2, 2.5, 2.3, 2.8, 2.2, respectively. Among the five streamflow depletion impact factors except rainfall condition, the change in groundwater usage showed the biggest influence on depletion, followed by the change in forest density, road construction, land use, and soil depth. In conclusion, it is anticipated that a national streamflow depletion assessment system to be develop in the future would provide customized depletion management and prevention plans based on the system assessment results regarding future data changes of the six streamflow depletion impact factors and the prospect of depletion progress.

• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.54-69
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• 2000

There are groundwater trouble by high-salinity yield inducing sea-water intrusion in Cheju Island. It is used groundwater-GIS(Well-lnfo) in the maintenance and management of groundwater in Cheju Island to grasp groundwater trouble area and cause of high-salinity yield. For 16 wells certain to yield high-salinity, we logged specific electrical conductivity(EC) and tried to get hold of freshwater and saltwater relationship. As result of distribution of $Cl^-$ by depth, it is showed up groundwater trouble by high-salinity yield in the east coastal area and the partly north coastal area. The reason of high-salinity groundwater yield are low-groundwater level by the structure of geology and low-hydraulic gradient etc. There is necessity for management to development and use of groundwater in the high-salinity area, special management area.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.566-573
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• 2016

In order to support effective usage of groundwater as an alternative water resource in future, we investigated distribution characteristics of minerals related with human health. While recent studies tended to focus on small scale, this study broadened research area up to nationwide scale to understand groundwater hydrology and regional, geological distributions of minerals in wide area; we investigated mineral distributions of national groundwater monitoring networks, developed GIS-based mineral maps, and reviewed correlation with geological features. As a result, calcium showed the highest concentration among 5 minerals (Ca, Mg, Na, K, Si) and potassium showed the lowest. Calcium concentration in limestone and sedimentary zone was the highest, and that in pore-volcanic-rock zone was the lowest. While calcium, magnesium and sodium showed differences in concentrations in intrusive-igneous-rock and sedimentary zone, potassium was not within geological features. When we studied regional differences, there were no tendency, but Jeju and Gangwon area showed differences in concentrations of calcium and silica.

• The Journal of Engineering Geology
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• v.21 no.2
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• pp.107-116
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• 2011

Groundwater level data and flowrate data were collected by considering the distance between the groundwater-level gauge station and flowrate gauge station (< 10 km) in the Geum River watershed, Baseflow was separated from the collected flowrate data using the WHAT SYSTEM, which is a Web- and GIS-based tool developed for hydrological applications, Correlation analysis was performed for the separated baseflow and groundwater-level data collected from a site close to the flowrate gauge station, Twenty regions were selected and data sets were collected from 2002 to 2008. Twelve regions yielded a correlation coefficient of > 0.5, When the data sets were analyzed for each year for all 20 regions, we obtained a correlation coefficient of 0.5-0.6 for 8 cases, 0.6-0.7 for 5 cases, and > 0.7 for 12 cases. For individual regions, the correlation coefficient varied from year to year. There was a tendency toward weak correlation in the case of drought or flood, Therefore, under normal conditions (i.e., neither flood nor severe drought), it is possible to estimate the baseflow from nearby groundwater-level data for regions with a high correlation coefficient.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.395-409
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• 2005

To explore submarine groundwater discharge (SGD) into the coastal zone of Jeju Island, the water quality analysis with seasonal remotely sensed data was carried out. If the groundwater is directly discharged into the ocean, the water quality of coastal zone is influenced. Therefore sea surface temperature (SST), the transparency, and Chlorophyll-a's concentration were analyzed for extracting the anomaly zone related with SGD using Landsat Thematic Mapper (TM) data acquired on April, August, and December. Then the spatial characteristics of springs, which located along the coastal area, were analyzed by CIS data integration based on Fuzzy logic. The integration results were compared with the anomaly zone extracted from Landsat TM data, and it is considered that springs has close relationship with SGD.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.2
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• pp.101-109
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• 1996

DRASTIC system was used in this study that was developed by U.S. EPA and is widely used for evaluating relative groundwater pollution potential by using hydrogeological factors. The DRASTIC system can be used for selection of well sites, selection of waste disposal sites and basic data of landuse for groundwater protection, and monitoring purpose and efficient allocation of resource for remediation. This study analyzed regional groundwater pollution potential around Chungju Lake using the DRASTIC system. Hydrogeological factors used in this study are depth to water, net recharge, aquifer media, soil media, slope and hydraulic conductivity. For accurate analysis, lineament density that is extracted from image processing of satellite image is overlaid to the DRASTIC system. Results of this study are mapped so groundwater pollution potential and risk degrees can be understood easily and quickly. A graphic user interface is developed to process the data conveniently.