• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1346-1350
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• 2009

SWAT 모형에서는 중간유출, 침루, 토양 증발, 식물에 의한 증산 등의 수문과정을 모사하기 위해서 토양 수대를 토양의 물리적 특성에 따라 몇 개의 층으로 구분하고, 각 층별로 순차적으로 각 성분량을 계산한다. 이 때 지표유출로 인한 영양물질 이송이 기작되는 영역을 설정하기 위해서 사용자가 입력한 첫 번째 토양층을 강제적으로 둘로 구분하여 상부 10mm의 새로운 토양층이 자동 생성되도록 알고리즘화되어 있다. 그러나, 동일한 토양 특성을 가진 층을 임의적으로 둘로 구분하는 것은 토양 물리적 관점에서 보면 적절하지 않으며, 또한 생성된 매우 얇은 상부 10 mm 토양층으로 인해서 포장용수량을 초과하는 과잉수가 커서 경사가 급한 유역이나 토양층의 투수성이 매우 큰 지역에 모형을 적용할 경우에는 중간유출량이 비현실적으로 크게 계산되는 문제를 수반한다. 따라서 본 연구에서는 중간유출이 크게 계산되는 문제점을 해결하고 토양층내의 수분 거동을 보다 현실적으로 모사하기 위해서 합체-분리 (combining-partitioning) 방식의 토양층 구조화 기법을 고안하고 SWAT의 지표하 유출 계산 모듈에 새롭게 추가하였다. 모형 개선이 수문 및 수질 성분 모의에 미치는 영향을 평가하기 위해서 충주댐 상류유역을 대상으로 모델링을 수행하고 상대비교를 한 결과, 토양수분, 중간 및 지하수유출, 인 순환에 미치는 영향이 가장 큰 것으로 분석되었다.

• 한국환경농학회지
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• 제19권5호
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• pp.433-441
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• 2000

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was used for irrigation water. The effluent was diluted to maintain the total nitrogen concentration below $26mg{\cdot}L^{-1}$ in the first year and used without dilution in the second year experiment. Growth components and yields were compared against the CONTROL plot where conventional method was applied. And also, soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed. Generally, addition of the treated sewage to the irrigation water showed no adverse effects on paddy rice culture, and even enhancement was noticed in both growth and yield. Irrigation of treated sewage after concentration adjusted with conventional fertilization showed the better result, and the yield exceeded that of CONTROL case where clean water was irrigated. Soil characteristics changed after irrigation, and significant EC increasing was observed for the reclaimed sewage irrigation plots. From this study, it appears that reuse of treated sewage, as supplemental irrigation water could be a feasible and practical alternative. For full-scale application, further study is recommended on the specific guideline of major water quality components in treated sewage for irrigation and public health.

• 한국환경복원기술학회지
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• 제10권3호
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• pp.1-7
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• 2007

For waste water treatment, artificial wetland was constructed in 1998. The size of artificial wetland is 20m${\times}$200m, with sand and gravel as media and Phragmites japonica was implanted. The removal rate of BOD, TN, and TP were 86%, 33% and 25% from June 2004 to November 2005 respectively, while those were 88%, 38% and 55% in 1999. Organic materials and nitrogen compounds are still effectively removed, after 6 years of construction, but the removal efficiency of phosphorus compounds is reduced. So for sustaining of artificial wetland as waste water treatment system, the removal efficiency of phosphorus compounds must be elevated.

• Journal of Astronomy and Space Sciences
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• 제31권2호
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• pp.131-140
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• 2014

Lava caves could be useful as outposts for the human exploration of the Moon. Lava caves or lava tubes are formed when the external surface of the lava flows cools more quickly to make a hardened crust over subsurface lava flows. The lava flow eventually ceases and drains out of the tube, leaving an empty space. The frail part of the ceiling of lava tube could collapse to expose the entrance to the lava tubes which is called a pit crater. Several pit craters with the diameter of around 100 meters have been found by analyzing the data of SELENE and LRO lunar missions. It is hard to use these pit craters for outposts since these are too large in scale. In this study, small scale pit craters which are fit for outposts have been investigated using the NAC image data of LROC. Several topographic patterns which are believed to be lunar caves have been found and the similar pit craters of the Earth were compared and analyzed to identify caves. For this analysis, the image data of satellites and aerial photographs are collected and classified to construct a database. Several pit craters analogous to lunar pit craters were derived and a morphological pit crater model was generated using the 3D printer based on this database.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.140-143
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• 2003

Air permeabilities in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona, exhibit a self-affine behavior, thus renders a field random fractal. Based up fractal scaling, the observed scale effect has been interpreted [Hyun et al., 2002]. Recently, Frantziskonis and Hansen [2000] presented that fractal scaling can be represented based on wavelets. This study deals with the way of using wavelets for fractal scaling. A numerical study is presented to examine the applicability of wavelet-based approach to determining upscaled air permeability values on various data supports at the site. To characterize the scaling property of self-affine fields generated based upon wavelets, Hurst coefficient, H. was inferred by applying the average wavelet coefficient (AWC) method. The result yielded H = 0.24, which is very close to the result of geostatistical analysis using a power variogram (H = 0.22). The study concludes that wavelet-based scaling is a useful way of determining parameter values on different data supports, which is an essential task for modeling of subsurface flow and mass transport in a numeric grid with different resolutions (grid size).

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.394-397
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• 2006

Hydrogeologic and hydrochemlcat conditions of two uncontrolled landfills without reliable underlying liners, leachate collection and treatment systems were compared. With similar weather conditions, spatial distribution and temporal variations of contaminants of concern and redox parameters were different for the two landfills. These differences are highly associated with ages and hydrogeologic settings of the landfills. Groundwater flow diverges from the Cheonan landfill while it converges to downgradient area in the Wonju landfill. Less permeable clayey silt layer or silty soil in the subsurface limited dispersion of leachate plume in the former landfill but highly permeable sandy soil with good lateral extent facilitated rapid plume dispersion in the latter landfill. In addition, hydraulic properties of the cover soil played a role in the different development of redox conditions, which resulted in significantly different concentrations of nitrates. Most problematic contaminants at downgradient wells of the landfills are ammonia and nitrate.

• 한국수자원학회논문집
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• 제37권6호
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• pp.509-515
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• 2004

본 연구에서는 국내에서 독자적으로 개발한 완전 연동형 SWAT-MODFLOW결합모형을 평가하였다. 결합모형은 함양량의 시공간적 변동성을 반영할 수 있어 기존 지하수 모델링에 있어서 함양량을 현실적으로 고려하지 못했던 부분이 크게 개선될 것으로 판단된다. 또한 SWAT의 지하수 모형성분은 집중형이므로 분포형 매개변수의 입력이 어렵고 지하수위의 변화 등을 고려하지 못하나 결합모형은 지하수부분에 MODFLOW모형을 탑재시킴으로써 완벽한 시간단계별 지하수위 분포를 재생해 낼 수 있었다. 마지막으로 하천네트워크-대수층간의 상호작용에 있어서 SWAT은 일방향만을 고려하나 결합모형은 양방향 상호작용을 모두 고려할 수 있어 실제적인 하천-대수층간의 경계유량을 고려할 수 있어 유역내 기저 유출량 및 총 유출량의 신뢰성이 크게 증대될 것으로 기대된다.

• 한국농공학회지
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• 제38권3호
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• pp.92-100
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• 1996

In order to control the water quality in rivers or lakes, it is needed to evaluate accurate amount of pollutant loadings from watersheds. The daily pollutant loadings were simulated using the pollutant loading calculation model which was composed of mathematical equations superimposed on the TANK model. The calibration of runoff and pollutant loading parameters were carried out with observed data, using a trial-and-error method. In addition, the proposed model was applied to evaluate its applicability for the representative watershed, the Bokha river watershed, Icheon city, Korea. The parameters of SS and T-P showed large values in the first tank while T-N showed large in the second tank. As a result of simulating the daily pollutant loadings by the pollutant loading calculation model, all of SS, T-N and T-P loadings were increased or decreased according to the amount of runoff discharge. Especially, it was apparent that SS and T-P loadings were significantly influenced by the runoff variation when it was rain. These results could partly explain that SS and T-P would occur mainly from the surface runoff while T-N would occur from both surface and subsurface flow.

• 한국물환경학회지
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• 제23권4호
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• pp.527-534
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• 2007

To operate scientifical and integrated management of water resources, it needs to identify clearly the quantitative variation and moving pathway of water resources in a basin. Moreover, it needs to also estimate more precisely the amount of runoff generating from the precipitation. Thus, in this study, to carry out more reliable hydrologic analyses, the runoff characteristics according to detailed runoff components and water balance in a basin are analyzed. As a result of yearly water balance analyses, during the period of drought year, the loss is bigger than that of 6-year mean loss and the return flow of groundwater is the most dominant component of runoff. During the period of flood year, the loss is smaller about 4% than that of 6-year mean loss and the subsurface water is the most dominant component of runoff. The loss due to the interception and evapotranspiration for 6-year mean loss is about 53% of the total rainfall, the mean runoff ratio is about 27% and the baseflow is about 22%.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권2호
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• pp.1-23
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• 2022

For its essential importance as a resource, sustainable development of groundwater has been major research interests for many decades. Conventional characterization of aquifer and groundwater has relied on borehole data from observation well. Although borehole data provide useful information on yield and flow of groundwater, it is often difficult and sometimes costly to estimate the spatial distribution of groundwater in entire aquifer. Geophysical probing is an alternative techique that provides such information due to its capability to image subsurface structures as well as to delineate spatial distribution of hydraulic parameters. This study presents various technical information about geophysical probing to estimate main characteristics of aquifer for groundwater exploitation. Subsequently, we analyzed representative cases, in which geophysical methods were applied to identify the location of the groundwater, classify freshwater and brine, derive hydraulic constants, and monitor groundwater.