• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.383-386
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• 2006

Subsurface temperature is affected by heat advection due to groundwater advection. Temperature-depth profile can be perturbed especially when there are significant vertical groundwater flux caused by external force such as injection or extraction. This research is to clarify the change of subsurface temperature distribution when the 40m x l0m sandy aquifer is stimulated by two different vertical flux($case1:\;{\pm}10^{-5}m^3/s,\;case2:\;{\pm}4{\times}10^{-5}m^3/s$) using a program called HydroGeoSphere. The resulting temperature distribution contour map shows pumping causes vertical attraction of water from deeper and warmer place which result in rising up isotherm. Additionally more injection/extraction rate, more vertical groundwater flux leads to faster Increase in temperature near the pumping well.

• Environmental Engineering Research
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• 제12권4호
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• pp.176-193
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• 2007

The ability to measure groundwater contaminant flux is increasingly being recognized as crucial in order to prioritize contaminated site cleanups, estimate the efficiency of remediation technologies, measure rates of natural attenuation, and apply proper source terms to model groundwater contaminant transport. Recently, a number of methods have been developed and subsequently applied to measure contaminant mass flux in groundwater in the field. Flux measurement methods can be categorized as either point methods or integral methods. As the name suggests, point methods measure flux at a specific point or points in the subsurface. To increase confidence in the accuracy of the measurement, it is necessary to increase the number of points (and therefore, the cost) of the sampling network. Integral methods avoid this disadvantage by using pumping wells to interrogate large volumes of the subsurface. Unfortunately, integral methods are expensive because they require that large volumes of contaminated water be extracted and managed. Recent work has investigated the development of an integral method that does not require extraction of contaminated water from the subsurface. We begin with a review of the significance and importance of measuring groundwater contaminant mass flux. We then review groundwater contaminant flux measurement methods that are either currently in use or under development. Finally, we conclude with a qualitative comparison of the various flux measurement methods.

• 물과 미래
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• 제28권3호
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• pp.133-142
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• 1995

호수지역에서, 호수의 위치가 지하수 flux에 미치는 영향을 파악하고 지하수와 호소수와의 교류관계를 관측하기 위한 감시망 설계에 대한 지침을 제공하기 위하여 호수의 위치를 달리하는 3종류의 가상 지하수 시스템을 설계하였다. 각각의 지하수 시스템에 대하여 3차원정상 모의발생을 행하였으며 다음과 같은 결과를 얻었다: (1) 호수의 위치가 지하수 시스템의 상류측에 위치할 때 보다 하류측에 위치하는 경우가 호소수와 지하수와의 고류가 활발하다. (2) 대상지역의 호수는 존재하는 위치에 상관없이 지하수가 호수로 유출되는 양보다 호소수가 지하수를 함양하는 양이 많다. (3) 호수의 위치가 유역의 상류층에 위치 할수록 지하수 유출입량의 비가 커진다. (4) 호수의 바닥부분에서 지하수의 수평방향 flux에 의한 교류는 연직방향 flux에 의한 교류 보다 훨씬 더 활발하다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.293-297
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• 2006

Submarine groundwater discharge (SGD) and the interface between seawater and freshwater in an unconfined coastal aquifer was evaluated by numerical modeling. A two-dimensional vertical cross section of the aquifer was constructed. Coupled flow and salinity transport modeling were peformed by using a numerical code FEFLOW In this study, we investigated the changes in groundwater flow and salinity transport in coastal aquifer with hydraulic condition such as the magnitude of recharge flux, hydraulic conductivity. Especially, transient simulation considering tidal effect and seasonal change of recharge rate was simulated to compare the difference between quasi-steady state and transient state. Results show that SGD flux is in proportion to the recharge rate and hydraulic conductivity, and the interface between the seawater and the freshwater shows somewhat retreat toward the seaside as recharge flux increases. Considered tidal effect, SGD flux and flow directions are affected by continuous change of the sea level and the interface shows more dispersed pattern affected by velocity variation. The cases which represent variable daily recharge rate instead of annual average value also shows remarkably different result from the quasi-steady case, implying the importance of transient state simulation.

• 자원환경지질
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• 제53권5호
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• pp.543-552
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• 2020

본 연구는 플로리다 주 Silver Springs 유역 내 카르스트 대수층의 지하수 플럭스를 측정하기 위해 플럭스미터(passive flux meter)와 단공희석시험(borehole dilution test)을 수행하였다. 또한 카르스트 대수층 내 분포하는 두 영역인 암반 매질(matrix)과 균열암반 매질(non-matrix)에 따른 플럭스미터의 성능도 함께 평가하였다. 그 결과 유속이 낮은 암반 매질 영역에서는 플럭스미터의 측정값(5.96 ± 1.75 cm/day)이 단공희석시험의 측정값(4.68 ± 2.99 cm/day)과 유사하게 나타났다. 반면, 유속이 빠른 균열암반 매질 영역에서는 플럭스미터의 측정값(9.94 ± 0.90 cm/day)과 단공희석시험의 측정값(1817.37 ± 1795.50 cm/day)이 큰 차이를 보였다. 이와 같은 결과는 지하수가 플럭스미터 내부 흡착제를 완전히 통과한다고 가정하였으나, 빠른 지하수 플럭스(>11 cm/day)를 가진 균열암반 매질 영역의 경우 지하수가 플럭스미터의 활성탄 담체를 통과하지 못하고 플럭스미터와 관측공 사이의 공간으로 우회하여 흐르기 때문으로 판단된다. 따라서 기존의 플럭스미터는 11 cm/day 이하의 지하수 플럭스 측정에 적합하며, 지하수 플럭스가 11 cm/day 이상인 대수층에서 사용할 수 있는 새로운 플럭스미터의 개발이 필요할 것으로 생각된다.

• Membrane and Water Treatment
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• 제2권4호
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• pp.239-250
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• 2011

A photovoltaic powered ultrafiltration and reverse osmosis system was tested with a number of natural groundwaters in Australia. The objective of this study was to compare system performance at six remote field locations by assessing the impact of water composition and fluctuating energy on inorganic contaminant removal using a BW30-4040 membrane. Solar irradiance directly affected pressure and flow. Groundwater characteristics (including TDS, salts, heavy metals, and pH), impacted other performance parameters such as retention, specific energy consumption and flux. During continual system operation, retention of ions such as $Ca^{2+}$ and $Mg^{2+}$ was high (> 95%) with each groundwater which can be attributed to steric exclusion. The retention of smaller ions such as $NO_3{^-}$ was affected by weather conditions and groundwater composition, as convection/diffusion dominate retention. When solar irradiance was insufficient or fluctuations too great for system operation, performance deteriorated and retention dropped significantly (< 30% at Ti Tree). Groundwater pH affected flux and retention of smaller ions ($NO_3{^-}$ and $F^-$) because charge repulsion increases with pH. The results highlight variations in system performance (ion retention, flux, specific energy consumption) with real solar irradiance, groundwater composition, and pH conditions.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1997년도 총회 및 춘계 학술발표회 논문집
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• pp.25-29
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• 1997

In many solute transport studies, either flux or resident concentration has been used. Choice of the concentration mode was dependent on the monitoring device in solute displacement experiments. It would be questionable, however. to accept the equivalency in the solute transport parameters between flux and resident concentrations in structured soils exhibiting preferential movement of solute. In this study, we investigate how they differ in the monitored breakthrough curves (BTCs) and transport parameters for a given boundary and flow condition by performing solute displacement experiments on a number of undisturbed soil columns. Both flux and resident concentrations have been simultaneously obtained by monitoring the effluent and resistance of the Horizontally-positioned TDR probes. The study reveals that soil columns having relatively high flux densities exhibited great differences in the degree of peak concentration and travel time of peak between flux and resident concentrations. The peak concentration in flux mode was several times higher than that in resident one. This was mainly due to the bypassing of solute through soil macropores.

• 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.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.99-102
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• 2001

The soil-to-air fluxes of three PAHs(Phenanthrene, Pyrene, Benzo(a)pyrene) from a laboratory contaminated forest soil were investigated in experimental microcosms. The effects of soil temperature(45$^{\circ}C$, $25^{\circ}C$, 5$^{\circ}C$) and relative humidity(0%, 100%) were investigated according to existence of the humic layer(O layer) over the mineral layer(A layer). Volatilization flux experiments were carried out for a period of 96 hrs. The resulting PAHs volatilization fluxes from the different conditions were quantified and compared. In the mineral layer, highest volatilization flux among the individual PAHs was Phenanthrene >Pyrene> Benzo(a)pyrene on the conditions of 45 $^{\circ}C$, RH=100%. In the humic layer over the mineral layer, maximum volatilization flux was Phenanthrene on the condition of 45$^{\circ}C$, RH=0%. Results from flux experiments showed that volatilization fluxes of PAHs were dependent on soil temperature. Existance of humic layer over the mineral layer delayed transportation to the air of especially heaveir molecular PAHs. But, if humic layer is contained water sufficiently, it is possible that volatilization fluxes are enhanced by water convective flux according to variation of soil temperature and air relative humidity.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.304-307
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• 2005

A numerical modelling method using a backward-in-time advection dispersion equation is introduced in assessing the vulnerability of groundwater to contaminants as an alternative to classical vulnerability mapping methods. The flux and resident concentration measurements are normalized by the total contaminants mass released to the system to provide the travel time probability density function and the location probability function. With the results one can predict the expected travel time of a contaminant from up stream location to a well and also the relative concentration of the contaminant at a well. More specific groundwater vulnerability can be mapped by these predicted measurements.