• Journal of Wetlands Research
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• v.15 no.1
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• pp.43-50
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• 2013

The groundwater-surface water interaction of Searsville Lake area, California, US was analyzed using 3-dimensional groundwater model. This study especially focuses on investigating the groundwater head drawdown near the lake when the abrupt decline of the lake water table occurs due to the implementation of the options to remove the accumulated sediments along the dam. The result of the investigation revealed that the groundwater head drawdown near the lake is not significant enough to adversely affect the wetland habitat of the area regardless of the hydrogeologic parameters of the aquifers. We expect this result provides useful information to the similar Korean case studies in which the surface water level abruptly changes due to the operation of the hydraulic gates of dams and wiers and the corresponding environmental impact should be considered.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.489-489
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• 2018

최근 기후변화의 영향으로 가뭄의 발생빈도 및 규모가 증가하고 있다. 이에 지자체를 중심으로 대체 수자원 확보를 목적으로 지하수의 개발이 늘어나고 있는 추세이다. 국내에서는 지하수 개발 이용시설로 관정(管井)을 활용하는 것이 일반적이나, 최근에는 낙도를 중심으로 대규모 지하수자원 확보를 위한 지하수댐 건설이 논의되고 있다. 현재 우리나라에는 6개의 지하수댐이 설치 운영되고 있는데, 가장 최근에 건설된 지하수댐도 20여 년이 지난 1998년에 건설되었다. 게다가 국내에 건설된 지하수댐은 지하수맥을 이용하기 보다는, 건천화된 시기에도 하천수를 이용하기 위해 하천의 지하에 건설되어 있어 일반적인 개념의 지하수댐이라고 보기 어렵다. 지하수댐의 활용을 통해 지하수자원을 효율적으로 확보하기 위해서는 첫째, 지하수에 대한 기초자료의 확보가 필요하다. 현재 지하수법 제5조에 따라 전국 지하수에 대한 기초조사를 실시하고 10년마다 보완조사를 실시하여야 한다. 그러나 1997년부터 실시되고 있는 기초조사는 예산 및 인력 부족 등으로 아직까지 전국 전체에 대한 자료가 마련되지 못하고 있으며, 보완조사는 아직까지 실시된 바가 없는 실정이다. 조속히 지하수 기초조사를 완료하여 전국에 대한 수문지질도(水文地質圖)를 작성하고, 이를 바탕으로 체계적인 지하수댐 조성계획을 수립할 필요가 있다. 둘째, 지하수댐 건설기술에 대한 체계적인 연구가 필요하다. 현재 조성된 하천 지하에 건설된 지하수댐이 아닌, 지하수맥을 이용하는 본래의 용도에 적합한 지하수댐을 건설하기 위한 세부기술의 확보가 필요해 보인다. 셋째, 현행 지하 충전수에 대한 수질기준을 확대할 필요가 있다. 현재 하수 폐수 및 온배수 재처리수로 지하수를 함양할 경우의 수질기준은 시 도지사가 관할 구역에 대하여 수립하는 '지역지하수관리계획'에 포함된 경우로만 되어 있어, 국가 또는 개인이 지하수를 함양할 경우에 적용되는 수질기준이 부재한 상태다. 또한 지하수 충전 깊이에 따라 토양에서 발생하는 정화능력에 차이가 있으므로, 수질기준에 차등을 두어 합리적으로 적용할 필요가 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.570-579
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• 2021

The environments in current farming and fishing communities have been exacerbated by the shortage of personnel caused by aging, the deficiency of equipment, and the decrease in produce prices. To help solve these issues, this study examined the history, such as inspections, failures, and repairs, by constructing a database for underground water wells, pumping stations, and irrigation, which are critical for management among agriculture production infrastructures. In particular, in the case of underground water wells, their optimal locations were determined using spatial information, such as a geological map of water resources, a water vein map, and underwater depth, because indiscreet installations and an absence of spatial information resulted in economic losses and environmental pollution. Therefore, this study could efficiently manage many facilities scattered in rural areas by developing a system. An analysis of the status of 14 underground water wells using spatial information showed that the location information at six points was specified incorrectly. On the other hand, a site investigation showed that the water vein map analysis at one point was inaccurate.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.313-313
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• 2022

일반적으로 가뭄은 특정지역에서 평균 이하의 강수량이 발생되는 현상으로, 강수량이 감소되면 토양수분, 하천수 수위, 저수지 수위, 지하수위 등이 순차적으로 감소한다. 수문학적 가뭄은 기상학적 가뭄 및 농업 가뭄에 비해 늦게 발현되는데, 이는 강수량의 부족이 토양수분, 하천수량, 지하수 및 저수지 수위 등과 같은 수문학적 시스템에 전이되는 시간이 소요되기 때문이다. 따라서, 가뭄 피해를 경감하기 위해 지하수위 변동성을 이용하여 지하수 함양량을 추정함으로써 효율적인 수자원 관리의 필요성이 증대되고 있다. 지하수위는 농촌 지하수 개발, 가뭄 및 홍수 예측 등 다양한 분야에 활용되며, 강수량에 의한 변화가 지표수에 비해 느리게 나타나고 토양을 통과하는 특성으로 인해 단기 및 장기간의 변화 경향이 나타난다. 미국 지질조사국 (United States Geological Survey)에서는 지하수위를 월 단위로 보통 이하 (Below-normal), 보통 (Normal), 보통 이상 (Above-normal) 3단계로 구분하여 분포도를 작성하고 전체 관측기간 중 25% 이상에서 보통 이하 (Below-normal)로 나타나면 가뭄으로 판단한다. 우리나라의 경우 지형, 유역을 고려한 지하수 수위 및 수질 현황과 변동성을 파악하기 위하여 전국 지하수위 관측망 688개소를 설치하고 운영 중에 있다. 또한, 농촌진흥청에서는 전국 농업기상대와 연계하여 토양수분관측망 (soil moisture monitoring network)을 구축하였으며, 표토 10 cm에 토양수분센서를 전국 168 지점에 설치하여 운영하고 있다. 본 연구에서는 강수량을 기반으로 산정한 표준강수지수 (Standardized Precipitation Index, SPI)와 지하수위를 기반으로 산정한 표준지하수위지수 (Standardized Groundwater Level Index, SGI), 토양수분관측망의 토양수분의 상관 분석을 수행하고자 한다. 밭작물 가뭄의 중요 요소인 토양수분 함량은 강수에 즉각적으로 반응하는 반면 지표수 및 지하수는 상대적으로 장기간의 강수에 영향을 받기 때문에, 본 연구의 결과는 향후 밭작물 지역의 가뭄 취약성을 관리하는 지표로 활용이 가능할 것으로 사료된다.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.303-314
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• 2020

Bottled water companies submit monthly hydrologic data including periodical environmental effects investigation, daily water production capacity, water production, water level, water chemistry (pH, EC, temperature) per hour and strictly manage groundwater by periodical analyses. Thus few problems concerning drawdown due to excess intake of groundwater take place. Nevertheless, bottled water companies are imprinted as a contribution to civil affairs resulted regarding groundwater near the companies. Therefore, a new method is required during water balance analysis in environmental effects evaluation, which should be compatible with the evaluation by hydrologic experts as well more accessible to non-experts. In this study, water level of surface water and recharge rate in subcatchment where water production wells are located were measured and monthly baseflow rates were separated from normal streams. Besides, recharge properties of groundwater and surface water in the same catchment area were estimated using analyses of oxygen and hydrogen isotopes in groundwater (production well), surface water, and rainfall.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.61-69
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• 2009

In mid-July, 2006 the torrential rainfall across Gangwon-do region caused 48 casualties and 1,248 houses submerged, resulting in damages with the restoration costs of 3 trillion and 512.5 billion won. This was because the topographic characteristics of Gangwon-do region for which mountainous areas mostly account increased the effects of landslide. In this study, the landslide region was shot using the PKNU No.4 system immediately after the occurrence of landslide in order to analyze it as objectively, exactly, and rapidly as possible. 1,054 areas with landslide occurrence were extracted by digitizing the shot images through visual reading after orthometric correction using ERDAS 9.1. Using the Arc GIS 9.2, a GIS program, hydrologic, topographic, clinical, geologic, pedologic aspects and characteristics of the landslide region were established in database through overlay analysis of digital map, vegetation map, geologic map, and soil map, and the status and characteristics of the occurrence of the landslide were analyzed.

• Korean Journal of Remote Sensing
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• v.21 no.6
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• pp.493-503
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• 2005

In this study, the weight of evidence(WofE) technique based on GIS was applied to spatially estimate the groundwater yield characteristics at the Pocheon area In Gyunggi-do. The groundwater preservation depends on many hydro-geologic factors that include hydrologic data, land-use data, topographic data, geological map and other natural materials collected at the site, even with man-made things. All these data can be digitally processed and managed by GIS database. In the applied technique of WofE, the prior probabilities were estimated as the factors that affect the yield on lineament, geology, drainage pattern or river system density, landuse and soil. We calculated the value of the weight values, W+ and W-, of each factor and estimated the contrast value of it. Results by the groundwater yield characteristic computation using this scheme were presented feasibility map in the form of the posterior probability to the consideration of in-situ samples. It is concluded that this technique is regarded as one of the effective techniques for the feasibility mapping related to the estimation of groundwater-bearing potential zones and its spatial pattern.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.326-326
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• 2016

The fault can be defined, in a geological context, as a rupture plane showing a significant displacement generated in the case that the local tectonic stress exceeds a threshold of rupture along a particular plane in a rock mass. The hydrogeological properties of this fault can be varied with the spatial distribution and the connectivity of void spaces in a fault. When the formation of fault includes the process of the creation and the destruction of void spaces, a complex relation between the displacement along the fault and the variation of void spaces. In this study, the variation of flow with the geometrical characteristics of the fault is simulated and analyzed by using the three-dimensional discrete fracture network model. Three different geometrical characteristics of the faults are considered in this study: 1) simple hydraulic conductive plane, 2) damaged zone, and 3) relay structure of faults.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.283-293
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• 2021

The homogeneity of the compacted ground was analyzed using drone-based remote terrain and gravity field data. Among the topographic elements calculated by the hydrological algorithm, the topographic curvature effectively showed the shape of the surface that occurred during the compaction process, and the non-uniformly compacted area could be identified. The appropriate resolution of the digital topography requires a precision of about 10 cm. Gravity field Interpretation was performed to analyze the spatial density change of the compacted ground. In the distribution of residual bouguer gravity anomaly, the non-homogeneously compacted area showed a different magnitude of gravity than the surrounding area, and the difference in compaction was identified through gravity-density modeling. From the results, it is expected that the topographic element and gravitational field analysis method can be used to evaluate the homogeneity of the compacted ground.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.483-498
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• 2022

Soil moisture is defined as water in the pores of the soil's unsaturated zone, and it is closely related to various hydrological processes. This study aims to provide meaningful data by identifying factors affecting soil moisture through comparing soil moisture content and soil permeability in a study area covering six different land use types in an agricultural region that is highly dependent on groundwater. We conduct auto-correlation analysis, spectral density analysis, and cross-correlation analysis using time-series data. Soil moisture content shows to have weak auto-correlation and memory effects, and precipitation appears to have a substantial influence on soil moisture content. Saturation hydraulic conductivity does not vary markedly with changing land use, and instead appears to be affected by the inhomogenous soil structure.