• 한국물환경학회지
• /
• 제27권1호
• /
• pp.115-119
• /
• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2000년도 추계학술대회
• /
• pp.87-90
• /
• 2000

The hydrogeochemical and isotopic studies on deep groundwater in the Munkyeong area, Kyeongbuk province were carried out. $CO_2$-rich groundwater (Ca-HC $O_3$ type) is characterized by low pH (5.8~6.5) and high TDS (up to 2,682 mg/L), while alkali groundwater (Na-HC $O_3$ type) shows a high pH (9.I~10.4) and relatively low TBS (72~116 mg/L). $CO_2$-rich water may have evolved by $CO_2$ added at depth during groundwater circulation. This process leads to the dissolution of surrounding rocks and Ca, Na, Mg, K and HC $O_3$ concentrations are enriched. The low Pc $o_2$ (10$^{-6.4}$atm) of alkali groundwaters seems to result from the dissolution of silicate minerals without a supply of $CO_2$. The $\delta$$^{18}$ O and $\delta$D values and tritium data indicate that two types of deep groundwater were both derived from pre-thermonuclear meteoric water. The carbon Isotope data show that dissolved carbon in the $CO_2$-rich water was possibly derived from deep-seated $CO_2$ gas. The $\delta$$^{18}$ S values of dissolved sulfate show that sulfate reduction occurred at great depths. The application of various chemical geothermometers on $CO_2$-rich groundwater shows that the calculated deep reservoir temperature is about 130~175$^{\circ}C$. Based on the geological setting, water chemistry and environmental isotope data, each of the two types of deep groundwater represent distinct hydrologic and hydrogeochemical evolution at depth and their movement is controlled by the local fracture system.m.

• 자원환경지질
• /
• 제27권1호
• /
• pp.93-100
• /
• 1994

이 연구는 위스컨신주 도어지역의 지하수계에서의 남성분의 이동과 불규칙한 검출에 대한 메카니즘을 규명하였다. 1991년 봄 충진기간 동안에, 세개씩의 수위정(piezometers)을 내장한 두곳의 관측정과 다섯군데의 가정우물에서 수위와 수질의 변화를 측정하였다. 충진현상에 대한 수위의 변화는 지하수의 충진이 약 4일에서 10일 정도 연체되면서 비교적 빠르게 일어남을 보여주며, 이것은 지하수의 충진이 실루리안 돌로마이트 대수층 내에서 높은 수리전도율(K)을 가진 지대를 통해서 일어나고 있음을 지시해준다. 지하수내의 납성분은 미립자에서만 발견되었고, 용융된 상태로는 검출되지 않았다. 그 농도는 0.2에서 $7.1{\mu}g/mg$인데, 이는 지하수내 총 납성분으로는 0.3에서 $4.7{\mu}g/l$이다. 충진사건부터 최대의 미립자가 가정우물까지 이동하는데 걸리는 연체시간은 약 19일에서 22일 이었다. 지하수내에서 납성분이 미립자와 더불어 있으므로, 가정우물 중에서도 높은 수리전도대와 연결된 우물에서만 납성분이 검출되고, 결과적으로 지역적 불규칙성을 유발한다. 또한 우물에서는, 충진사건에 의한 지하수계로의 미립자의 유입량의 변화, 미립자의 이동에 따른 연체현상, 그리고 이동중의 분산 등으로 인해서 납성분의 농도가 채취하는 시간에 따라서 다르게 나타난다.

• 농촌계획
• /
• 제24권2호
• /
• pp.47-58
• /
• 2018

Protected horticultural complexes would increase crop productivity but would adversely affect the groundwater recharge function in the area because the impervious area would increase. Further, they would limit the movement of living beings, affecting biodiversity. Therefore, this study evaluated the groundwater ecosystem services provided by protected horticultural complexes in terms of consistent utilization of water. The estimated amounts of groundwater loss obtained through quantitative assessment of groundwater infiltration showed that a higher impervious area results in higher losses. We, therefore, predict a much higher loss if similar changes in land use are realized on a nationwide scale. A plan to promote groundwater recharge in impervious areas is actively being discussed for urban areas; however, this plan is not yet applicable to farming areas. We consider it is essential to develop groundwater infiltration facilities for horticultural complexes, infiltration trenches, permeable pavements, surface water storage facilities, water purification facilities, etc. Further research and development of groundwater infiltration facilities is important for consistent utilization of water and the improvement of ecosystem services.

• 한국터널지하공간학회 논문집
• /
• 제21권5호
• /
• pp.699-715
• /
• 2019

도시기반시설인 지중관거의 노후화가 심화되면서, 최근 도심지의 관거 주변에서 공동발생과 지반함몰 사례가 빈번하게 보고되고 있다. 지중관거 균열과 관련된 공동발생 및 지반함몰에 대해 많은 연구가 수행된 바 있으나, 기존 연구내용은 주로 관거의 균열 발생원인과 지반침하 거동에 집중되어 있다. 본 연구에서는 관거의 균열을 통한 지하수와 토립자 유출특성과 공동발생 메커니즘을 조사하였다. 또한, 토사유출로 인해 공동이 발생하고 지반함몰로 발전해가는 과정에 대한 가설을 수립하여 토립자 유출의 수리적 특성을 규명하고자 하였다. 관거 균열을 통한 토립자 유출 및 공동발생 메커니즘 규명을 위해 실내모형실험을 수행하였다. 모형실험으로부터 관거 균열을 통해 유출된 토립자를 측정하고, 실험과정을 영상촬영하여 PIV 분석을 통해 입자의 이동특성을 조사하였다. 본 연구를 통해 지중에서 발생하는 토립자의 이동, 공동발생 및 지반함몰 거동은 근본적으로 지하수의 이동에 의해 발생하는 것이며, 균열 위치와 관거 형상에 영향을 받음을 확인하였다.

• 농업과학연구
• /
• 제45권3호
• /
• pp.521-532
• /
• 2018

In recent decades, the dry stream phenomena of small and medium sized rivers have been attracting much attention as an important social problem. To prevent dry stream phenomena, it is necessary to build an infrastructure that manages rivers. To accurately determine the progress of dry stream phenomena, it is necessary to continuously measure the discharge and other hydrological factors for small and medium sized rivers. However, until now, the flow data for small and medium rivers in Korea has been insufficient. To overcome the lack of supporting data for supporting rational decision-making in policy and project implementation, a short- and long-term hydrological model was developed that takes into consideration hydrological changes such as the increase of the impervious area due to urban development and groundwater pumping, the construction of a large-scale sewage treatment plant, the maintenance of stream-oriented rivers, etc. In the developed model, the distributed grid is represented by three layers: Surface flow, interflow, and groundwater flow. The surface flow and intermediate flow flowed along the flow direction, and the groundwater flow was calculated by a two-dimensional groundwater analysis model such that the outflow occurred in all directions without a specific flow direction. The effects of land use and cover on evapotranspiration and infiltration and the effects of multiple landscapes can be simulated in the developed model.

• 지질공학
• /
• 제3권3호
• /
• pp.241-252
• /
• 1993

미국 위스컨신주 도어 지역의 지하수내에서 납성분이 시기적, 장소적으로 불규칙하게 산출되었다. 본 연구에서, 지하수의 납성분의 오염도를 나타내주는 지시자들(검출빈도, 납성분의 평균, 최고 검출농도)과 지하수의 납 오염에 관계가 있을 가능성이 있는 7개의 독립변수들과의 상관계수가 계산되었다. 이 관계의 통계적 중요성은 t-test에 의하여 90%의 신뢰도에서 이루어졌으며, 이 지역에 산재하는 농약(lead-arsenate)의 처리장소가 지하수내 납성분의 요염 원인임을 통계학적으로 입증하였다. 납성분으 산출농도가 높았던 5개의 가정우물로부터 총 112개의 지하수시료가 채취분석되었다. 납성분은 $0.45{\;}\mu\textrm{m}$의 공극 크기를 지닌 여과지에 걸러진 미립자에서 검출되었으며, 여과액에서는 검출되지 않았다. 이러한 결과는 납성분이 이 지역의 지하수내에서 미립자이 상태로 존재함을 지시한다. 따라서, 이 지역에서 납성분의 불규칙한 산출은 미립자상의 납이 수평과 수직으로 발달된 파쇄대와 같은 유동경로를 따라 이동하면서 나타나는 현상으로 고려된다.

• Geomechanics and Engineering
• /
• 제15권3호
• /
• pp.851-859
• /
• 2018

There are two primary causes of the ground movement due to tunnelling in urban areas; firstly the lost ground and secondly the groundwater depression during construction. The groundwater depression was usually not considered as a cause of settlement in previous research works. The main purpose of this study is to analyze the combined effect of these two phenomena on the transverse settlement trough. Centrifuge model tests and numerical analysis were primarily selected as the methodology. The characteristics of settlement trough were analyzed by performing centrifuge model tests where acceleration reached up to 80g condition. Two different types of tunnel models of 180 mm diameter were prepared in order to match the prototype of a large tunnel of 14.4 m diameter. A volume loss model was made to simulate the excavation procedure at different volume loss and a drainage tunnel model was made to simulate the reduction in pore pressure distribution. Numerical analysis was performed using FLAC 2D program in order to analyze the effects of various groundwater depression values on the settlement trough. Unconfined fluid flow condition was selected to develop the phreatic surface and groundwater level on the surface. The settlement troughs obtained in the results were investigated according to the combined effect of excavation and groundwater depression. Subsequently, a new curve is suggested to consider elastic settlement in the modified Gaussian curve. The results show that the effects of groundwater depression are considerable as the settlement trough gets deeper and wider compared to the trough obtained only due to excavation. The relationships of maximum settlement and infection point with the reduced pore pressure at tunnel centerline are also suggested.

• 터널과지하공간
• /
• 제3권1호
• /
• pp.24-32
• /
• 1993

Groundwater movement is one of the most important elements in the construction and management of underground oil storage cavern. To control the groundwater flow, grouting is run in parallel with water curtains. But as traditional grouting is conducted within cavern before and after excavation, the effect of grouting is delayed and the injection sphere is limited in the rock mass. Therefore, it is desirable to introduce a more extensive and effective grouting. This article is to present the caly grouting, which was the first to be carried out in the construction of underground caverns for oil storage in Japan. After conducting the clay grouting, the effect was confirmed by ground water level and infiltration quantity to the caverns.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.511-514
• /
• 2003

Nowadays, wells tapping the deep aquifers become general because water quality of the shallow groundwater has been gradually degraded over the last 30 years as a result of rapid industrialization and intensive agricultural activities. However, many of the deep wells also suffer problems of water-quality degradation in several years after the well installation, nevertheless those were properly completed and managed. It is believed that the heavy pumping from deep wells causes the doward movement of the contaminated, shallow groundwaters and introduces them into the deep aquifers. In this study, we introduces a shallow capture well system, which could effectively prevent the shallow groundwaters of poor water duality from moving into the deep aquifers by pumping of deep production wells. Even though additional costs are required to apply this system, we believe that this method could be appropriate for the deep wells that are important for the public health.