• 자원환경지질
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• 제46권1호
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• pp.39-50
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• 2013

간척지를 포함하고 있는 연구지역에서 육지에서 해안지역으로 근접할수록 측정된 지하수의 산화환원 전위 (Eh)와 용존 산소량 (DO)은 낮게 관찰되었다 (Eh: 0.57 V ${\rightarrow}$ 0.13 V, DO; 9.7 mg/l ${\rightarrow}$ 1.3 mg/l). 이는 연구지역 지하수의 산화환경이 육지에서 해안가로 근접할수록 호기성 환경에서 아혐기성/혐기성 환경으로 변화한다는 것을 의미한다. 또한 지하수 수질 분석 결과에 의하면 철이온 (Fe)이 지하수에 많이 포함되어 있으며 (> 20 mg/l), 대부분의 2가 철로 존재한다. 이러한 연구지역 해안가 지하수들의 특징들은 지하수들이 철의 환원작용 (Fe reduction)이 일어날 수 있는 혐기성 환경에 위치하고 있음을 지시해준다. 철 환원작용이 일어나기 위해서는 3가 철의 공급원이 필요한데, 관측정 퇴적물의 철이온 추출실험에 의하면 연구지역의 퇴적물은 철 환원작용에 필요한 3가 철이온에 대한 충분한 공급원 역할을 할 수 있다. 따라서 분석한 지하수 및 퇴적물의 결과들을 종합해석하면, 연구지역에서 일어나는 철 환원작용은 갯벌의 간척활동과 많은 관련을 가지고 있는 것으로 추정된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제6권3호
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• pp.73-91
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• 2001

미국지질조사소 NAWQA 프로그램에서 선정한 기준에 따라, 도시지역에서 채취한 도로를 흐르는 빗물과 일부 지하수의 휘발성유기화합물의 오염을 평가하기 위해 62개 휘발성유기화합물을 선택하였다. 62개 휘발성유기화합물은 3종류의 aromatic hydrocarbons, 13 종류의 alkyl benzenes, 1개의 ether, 26종류의 halogenated alkanes, 10종류의 halogenated alkenes 및 9종류의 halogenated aromatics를 포함하고 있다. 서울시 지역의 도로를 흐르는 빗물과 지하수의 휘발성유기화합물의 함량은 2000년 3월, 6월 및 11월에 시료를 채취하여 분석하였다. 모두 78개 시료(44개 도로를 흐르는 빗물시료, 27개 지하수 시료, 7개 하수종말처리장의 시료)가 채취되었으며, purge and trap 방법으로 추출하여 GC-MS로 분석하였다. 그 결과, alkyl benzenes과 aromatic hydrocarbons이 서울지역에서 자동차 통행에 의해 가장 영향을 받는 유기화합물이다. 분석된 62개 휘발성 유기화합물 중, 도로에 흐르는 빗물에서 검출되지 않은 휘발성유기화합물 성분은 단지 11개 성분뿐이었으나, 채취된 지하수에서 검출된 휘발성유기화합물은 14개 성분만이 검출되었다. 도로를 흐르는 빗물에서의 톨루엔 함량은 시료 채취 장소에 따라 변화가 매우 심하고, 0.1-29,310ppb이다. 벤젠의 함량은 0.05-33.0ppb, ethylbenzene은 0.05-960ppb, trichloromethane(chloroform)은 0.08-20ppb, trichloroethylene(TCE)는 0.03-4.30ppb, 1,1,2 trichloroethane은 0.1-50.0ppb이다. 채취된 일부 지하수 시료에 대한 예비조사 결과, dichloromethane(methylene chloride), trichloromethane(chloroform)와 toluene 등이 가장 자주 검출되는 성분이었다. 대부분의 aromatic hydrocarbons, alkyl benzenes및 다른 유기용매 성분은 검출농도 이하이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.8-9
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• 2011

On 4 September 2010 an earthquake of magnitude 7.1 on the Richter scale occurred on the Canterbury Plains in the South Island of New Zealand. The Canterbury Plains are an area of extensive groundwater and spring fed surface water systems. Since the September earthquake there have been several thousand aftershocks (Fig. 1), the largest being a 6.3 magnitude quake which occurred close to the centre of Christchurch on 22February 2011. This second quake caused extensive damage to the city of Christchurch including the deaths of 189 people. Both of these quakes had marked hydrological impacts. Water is a vital natural resource for Canterburywith groundwater being extracted for potable supply and both ground and surface water being used extensively for agricultural and horticultural irrigation.The groundwater is of very high quality so that the city of Christchurch (population approx. 400,000) supplies untreated artesian water to the majority of households and businesses. Both earthquakes caused immediate hydrological effects, the most dramatic of which was the liquefaction of sediments and the release of shallow groundwater containing a fine grey silt-sand material. The liquefaction that occurred fitted within the empirical relationship between distance from epicentre and magnitude of quake described by Montgomery et al. (2003). . It appears that liquefaction resulted in development of discontinuities in confining layers. In some cases these appear to have been maintained by artesian pressure and continuing flow, and the springs are continuing to flow even now. In spring-fed streams there was an increase in flow that lasted for several days and in some cases flows remained high for several months afterwards although this could be linked to a very wet winter prior to the September earthquake. Analysis of the slope of baseflow recession for a spring-fed stream before and after the September earthquake shows no change, indicating no substantial change in the aquifer structure that feeds this stream.A complicating factor for consideration of river flows was that in some places the liquefaction of shallow sediments led to lateral spreading of river banks. The lateral spread lessened the channel cross section so water levels rose although the flow might not have risen accordingly. Groundwater level peaks moved both up and down, depending on the location of wells. Groundwater level changes for the two earthquakes were strongly related to the proximity to the epicentre. The February 2011 earthquake resulted in significantly larger groundwater level changes in eastern Christchurch than occurred in September 2010. In a well of similar distance from both epicentres the two events resulted in a similar sized increase in water level but the slightly slower rate of increase and the markedly slower recession recorded in the February event suggests that the well may have been partially blocked by sediment flowing into the well at depth. The effects of the February earthquake were more localised and in the area to the west of Christchurch it was the earlier earthquake that had greater impact. Many of the recorded responses have been compromised, or complicated, by damage or clogging and further inspections will need to be carried out to allow a more definitive interpretation. Nevertheless, it is reasonable to provisionally conclude that there is no clear evidence of significant change in aquifer pressures or properties. The different response of groundwater to earthquakes across the Canterbury Plains is the subject of a new research project about to start that uses the information to improve groundwater characterisation for the region. Montgomery D.R., Greenberg H.M., Smith D.T. (2003) Stream flow response to the Nisqually earthquake. Earth & Planetary Science Letters 209 19-28.

• 지질공학
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• 제27권3호
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• pp.313-322
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• 2017

본 연구의 목적은 지표수-지하수 통합 모델을 통해 모델 영역과 시설농업단지(밀양들)의 지표수/지하수 유동을 모의하고 모델 영역의 물수지 분석을 통해 지하수 함양량을 산정하는 것이다. 지표수 유동 모델 결과에서는 밀양강 상류(북동쪽)에서 하류(남동쪽)로 약 1~5 m의 수심으로 지표수가 유동하고 있으며, 모델지역 상류의 M01 지점에서는 지표수 유량 관측값과 모델값이 일치하고, 모델지역 하류의 M02 지점에서의 지표수 유량은 1% 정도의 차이를 보인다. 지하수 유동 모델에서는 지하수 심도가 하천에서는 표고와 유사하며 산림 지역으로 갈수록 높아지고, 지하수 양수를 고려한 지하수 심도는 모델값이 관측값보다 1.5 m이내의 범위로 높게 나타난다. 지표수-지하수 통합모델에서는 지하수의 함양 면적이 모델 면적의 90% 정도이고, 지하수 함양량은 $1.92{\times}10^5m^3/day$인 것으로 나타난다. 연평균 물수지 분석에서는 단위 면적당 지하수 함양량이 503.9 mm/year로서 연평균 강우량의 39% 정도로 추정된다.

• 한국물환경학회지
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• 제33권6호
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• pp.661-669
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• 2017

A distributed watershed model CAMEL (Chemicals, Agricultural Management and Erosion Losses) was applied to a small rural watershed where intensive livestock farming sites are located to estimate nitrate leaching rates from soil to groundwater. The model was calibrated against the stream flows, and T-N and $NO_3-N$ concentrations were observed at the watershed outlet for three rainfall events in 2014. The simulation results showed good agreement with the observed stream flows ($R^2=0.67{\sim}0.93$), T-N concentrations ($R^2=0.40{\sim}0.58$) and $NO_3-N$ concentrations ($R^2=0.43{\sim}0.65$). The estimated annual nitrate leaching rate of the watershed was 33.0 kg N/ha/yr. The contributing proportions of individual activities to the total nitrate leaching rate of the watershed were estimated for livestock farming, applications of chemical fertilizer, and manure. The simulation results showed that the highest contributor to the nitrate leaching rate of the watershed was chemical fertilizer applications. The simulation period was for one year only, however, and results may vary depending on different conditions. Gathering input data over a longer period of time and monitoring data for calibration is needed. When this has been accomplished, it is expected that this model can be applied to small rural watersheds for evaluating temporal and spatial variations of nitrogen transformations and transport processes.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권1호
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• pp.66-72
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• 2010

The partitioning tracer method is to estimate the residual saturation of nonaqueous phase liquid (NAPL) in soils by analyzing tracer's retardation induced by the reversible partitioning of tracer with NAPL. This study is to estimate the residual diesel saturation in soils using the partitioning tracer method. Two-dimensional soil box was used to represent the 2-dimensional flows of groundwater and tracer solution in the saturated aquifer, and the soil box was filled with soil and then saturated with water. The residual diesel saturation was induced in saturated soil, and the partitioning tracer method was applied. The results from batch-partitioning experiment indicated that the diesel-water partitioning was linear with respect to tracer's concentration, and the partition coefficient of tracer between diesel and water was measured by their linearities. The groundwater flow in the saturated aquifer was simulated in the 2-dimensional soil box, and the residual diesel contamination was visually identified. The results from the partitioning tracer method with or without diesel in soils confirmed that 4-methyl-2-pentanol, 2-ethyl-1-butanol and 1-hexanol, can be used as a detecting method for diesel contamination. By the accuracies of estimations for diesel contamination using the partitioning tracer method, 2-ethyl-1- butanol showed the highest accuracy with 83%.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권2호
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• pp.61-76
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• 2011

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 their physical flows and chemical compositions from April to July in 2010. Ground waters in most wells were found at depths within 5 m from the ground surface, showing typical water-table aquifer systems. Hydraulic gradients indicate water resources in Gyeongbokgung, Changdeokgung, and Changgyeonggung flowing toward south, and toward east in Deoksugung area. Especially, water-level fluctuation data at S-10 in Deoksugung implied the influence of groundwater discharge facility. In Jongmyo Shrine, water was not detected in wells, indicating the water level was lower than the well depth. Based on the water chemistry and stable isotope analyses, water resources and their qualities appeared to be formed by the water-rock interaction along the groundwater paths. S-10 (Deoksugung) and S-14 (Changgyeonggung) samples were contaminated with nitrate ($NO_3$) in levels of higher than Korean drinking water standard, 10 mg/L as $NO_3$-N, but once in four sampling campaigns. In the situation that water resources in Palaces still maintain natural characteristics, the materials that will be used for the restoration and improvement of the Palace water supplies should be carefully selected not to disturb the natural integrity. In addition, because the wells are located in the center of metropolitan area, a systematic monitoring should be applied to detect and to manage the potential impacts of underground construction and various pollution sources.

• 지구물리와물리탐사
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• 제9권3호
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• pp.231-240
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• 2006

화산섬 제주도에서 용암분출에 따른 물리검층 반응특성을 고찰하기 위하여 다양한 물리검층을 수행하였다. 지질조사 목적으로 다양한 물리검층을 수행한 사례가 없어 제주도 지질의 특이성에 대한 이해의 폭이 물리검층 자료의 해석에 매우 중요한 역할을 한다. 제주도의 지하수자원의 체계적인 개발과 보전 목적으로 해안을 중심으로 해수침투관측망을 구축하고 있다. 이들 해수침투관측망 중에서 나공 시추공에 대한 물리검층 결과, 지하수위 하부인 포화대 구간에서의 물리검층 반응은 용암의 누층과 관련된 반응이 뚜렷이 확인되었으며 특히, 중성자검층, 감마-감마(밀도)검층 및 전기비저항검층은 용암유동의 특성을 잘 반영하였다. 수중화산쇄설성퇴적층은 높은 공극률, 낮은 전기비저항과 밀도를 나타냈다. 제주도 지역에서 수행한 물리검층 자료는 지질학적인 특성을 잘 반영하고 있어 물리검층의 적용성이 높은 것으로 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.1-10
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• 2012

Throughout much of the world, many ecological problems have arisen in watersheds where a significant portion of stream flows are diverted to support agriculture production. Within endorheic watersheds (watersheds whose terminus is a terminal lake) these problems are magnified due to the cumulative effect that reduced stream flows have on the condition of the lake at the stream's terminus. Within an endorheic watershed, any diversion of stream flows will cause an imbalance in the terminal lake's water balance, causing the lake to transition to a new equilibrium level that has a smaller volume and surface area. However, the total mass of Total Dissolved Solids within the lake will continue to grow; resulting in a significant increase in the lake's TDS concentration over time. The ecological consequences of increased TDS concentrations can be as limited as the intermittent disruption of productive fisheries, or as drastic as a complete collapse of a lake's ecosystem. A watershed where increasing TDS concentrations have reached critical levels is the Walker Lake watershed, located on the eastern slope of the central Sierra Nevada range in Nevada, USA. The watershed has an area of 10,400 sq. km, with average annual headwater flows and stream flow diversions of 376 million $m^3/yr$ and 370 million $m^3/yr$, respectively. These diversions have resulted in the volume of Walker Lake decreasing from 11.1 billion m3 in 1882 to less than 2.0 billion $m^3$ at the present time. The resulting rise in TDS concentration has been from 2,560 mg/l in 1882 to nearly 15,000 mg/l at the current time. Changes in water management practices over the last century, as well as climate change, have contributed to this problem in varying degrees. These changes include the construction of reservoirs in the 1920s, the pumpage of shallow groundwater for irrigation in the 1960s and the implementation of high efficiency agricultural practices in the 1980s. This paper will examine the impacts that each of these actions, along with changes in the region's climate, has had on stream flow in the Walker River, and ultimately the TDS concentration in Walker Lake.

• 방사성폐기물학회지
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• 제11권3호
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• pp.179-192
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• 2013

본 연구는 경상북도 경주시 양북면 지역의 결정질 암반의 지하수위 모니터링 자료를 이용하여 지하수 유동 특성을 평가하였다. 시계열분석 결과, 수리 지질 특성과 강우 사건을 반영한 4가지 변동 유형으로 분류할 수 있다. 유형 1(DB1-1, DB1-2)은 지하수위가 강우 사건의 영향을 가장 크게 받고 있다. 유형 2(DB1-3, DB1-7, KB-1, KB-2, KB-3, KB-7, KB-14, KB-15)는 공간적으로 단열대 주변에 분포하여 지하수투수특성대 발달이 우수하기 때문에, 강우의 직접적인 침투와 주단열대를 통한 지하수 유동이 동시에 나타난다. 유형 3(DB-5, DB1-6, DB2-2, KB-10, KB-11, KB-13)은 주단열대와 원거리에 분포한 결정 질 암반에 위치되기 때문에 강우의 직접적인 침투 영향보다는 고지대의 함양지역에서 소규모의 단열대를 통한 지하수 유동이 우세하게 일어난다. 유형 4(DB1-8, KB-9)는 결정질암반의 다양한 불균질성에 의해 지하수위 변동이 영향을 받고 있다.