전기비저항, 탄성파 그리고 GPR 탐사를 활용한 충적층 탐사

박충화,원경식,변지환,민대홍,윤형구 한국지반공학회 2013 한국지반공학회논문집 Vol.29 No.9

The geophysical methods have an advantage for investigating the wide area with low cost, and thus the application of these methods has been increased. The objective of this paper estimates the characteristics of alluvium through the geophysical methods including elastic wave, electrical resistivity and ground penetration radar. And the standard penetration test is also carried out for verifying the geophysical data with comparison. The sources of elastic wave method are divided into hammer and sissy and the electrical resistivity method is applied with different sizes, shapes and arrays of electrode for deciding the effective way. The center frequency is determined to be 270 MHz for considering the characteristics of soil. The results of ground penetration radar are also compared with those of standard penetration test. The high resolution shows when the source is a sissy in elastic wave method, however, the water level is not identified. In the electrical resistivity method, the non-polarizable electrode and schlumberger array show highly reliable data and the resolution of ground penetration radar is low. Thus, the results of this study are widely applied for determining the appropriate method when investigating the characteristics of alluvium.

충적대수층을 이용한 지열히트펌프시스템의 냉방성능

강병찬(Kang, Byung-Chan),박준언(Park, Jun-Un),이철우(Lee, Chol-Woo),송윤호(Song, Yoon-Ho) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.11

Alluvium is sedimentary stratum and composed of gravel, sand, silt, clay. Permeability of alluvium is the higher. If alluvium have lots of aquifer, will be of great use heat source and heat sink of heat pump. Alluvium aquifer contain the thermal energy of surrounding ground. Also geothermal heat pump using alluvium aquifer reduce expenses than general geothermal heat pump, because geothermal heat pump using alluvium aquifer make use of single well. In this study geothermal heat pump using alluvium aquifer was installed and tested for a building. The heat pump capacity is 30USRT. Temperature of ground water is in 12{sim}17?C annually and the quality of the water is as good as living water. The heat pump cooling COP is 4.4 ~ 4.7. The system cooling COP is 3.25 ~ 3.6. This performance is as good as BHE type ground source heat pump.

화강암 분지를 흐르는 미호천의 지형학적 특색

김영래 ( Kim¸ Young Rae ) 한국지형학회 2021 한국지형학회지 Vol.28 No.3

The drainage area of the Miho stream is composed of granitic basins, gneissic and sedimentary mountains. 80 percent of the Miho stream flows through the Jincheon basin and the Cheongju inner-plain within the Daebo granite belt. Because the deep weathering of granitic hills provides a large amount of sands to the streams, there are wide floodplains with thick alluvium developed in the basin and plain. The thickness of the alluvium is 5~10m and the width of the floodplains is 2~2.5km. In the basin outlet area where a stream passes through the mountain canyon, wide floodplains and deep alluvium are developed in other riverside. The Miho stream is a sand-gravel channel flowing through the Cheongju inner-plain with wide floodplains and deep alluvium formed by deep weathering of granite.

국가 지하수 관측망의 충적 및 암반 지하수의 지구화학적 특성

변지영,김여상,구민호 공주대학교 과학교육연구소 2004 과학교육연구 Vol.35 No.-

본 연구의 목적은 현재 설치된 국가 지하수 관측망의 지하수를 광역적이고 특징적인 지질에 따라서 구분하고, 동일 지점의 천부지하수와 암반지하수의 지구화학적 특성을 비교 분석하는 것이다. 102개 관측소에 있는 148개 지하수공의 자료가 분석되었다. 35개 관측소의 75개 지하수공의 자료는 지역적인 지질 특성을 반영하고 있으나, 지하수 유형의 진화 여부로는 충적지하수공과 암반지하수공의 지구화학적 특성이 거의 구별되지 않는다. 이는 관측공 대부분이 깊이 100m 미만의 우물이기 때문에 암반지하수가 충적지하수의 수질특성을 반영하였기 때문인 것으로 판단된다. 35개 관측소 중 30개 관측소는 관입화성암류(불국사화강암, 대보화강암)와 변성암 지대에 위치하고 있으며, 이들의 수질 유형은 Ca-Na-HCO_(3)와 Ca-Mg-HCO_(3)이다. 각 이온들의 농도는 TDS에 대하여 정의 관계를 가지고 있으며, pH에 대해서는 관련성이 없고, NO_(3)에 대해서는 일부 관측소에서 관련성이 높게 나타났다. Water quality data obtained from 148 monitoring wells of the National Groundwater Monitoring Network are analyzed to investigate the hydrogeochemical characteristics of alluvium and bedrock groundwaters of Korea. Although 70 cells data of 35 sites reflects the influence of the water-rock interaction, the distinctive differences of geochemical characteristics between the alluvium and the bedrock groundwater are not found. This is interpreted that bed rock groundwater reflects the water properties of alluvium groundwater because most of monitoring wells are installed at depths less than 100m. The 30 sites among 35 sites are located in the area of the intrusive granitic rocks and metamorphic rocks, and their chemical water types determined by Piper diagram are Ca-Na-HCO_(3) and Ca-Mg-HCO_(3), mainly due to the dissolution of the plagioclase in the granitic and metamorphic rocks. The concentrations of major ions are linearly proportional to TDS, not correlated with pH, and highly correlated with NO_(3) in some sites.

전기비저항 및 지구통계학을 활용한 충적층의 간극률 주상도 산정

민대홍,윤형구 한국방재학회 2015 한국방재학회논문집 Vol.15 No.5

The geostatistical method has been applied to predict the properties of area which has the limitation of survey. The objective of this study is to suggest the profiles of porosity based on the electrical resistivity in alluvium soil through the geostatistical method and the consideration, when applied the geostatistical method, is also suggested. An area of alluvium is chosen the site for applying the geostatistical method because an area has limitation in applying the geophysical method. In particular, the application of electrical resistivity survey is difficult because the current flow is limited into the dried and alluvium soils. The three profiles are adopted to obtain the electrical properties and the Archie's law is applied to convert the measured electrical resistivity to porosity. The Standard Penetration Test (SPT) is also performed to verify the reliability of estimated porosity and the result show the similar trend. And the effect of various statistical functions is also investigated and the slightly different distribution is observed. 지구통계학은 각 측정값들 간의 확률적인 상관성으로 미지의 값을 예측하며 지반조사가 어려운 지역의 물성치 예측에 활용되고 있다. 본 연구에서는 이러한 지구통계학 기법을 활용하여 전기비저항으로 도출된 간극비의 고해상 주상도를 제시하고 분석시 고려사항을 제시하고자 하였다. 지구통계학 기법이 활용된 지역은 전기비저항 탐사시 지층의 퇴적조건으로 인하여 전류 주입이 어려워 지층 특성 분석에 한계가 있는 충적층을 대상으로 하였다. 3개의 측선에서 측정한 전기비저항 탐사 데이터를 이용하여 비탐사된 미지의 값을 예측하고자 하였다. 측정한 전기비저항 데이터는 Archie's law를 통해 설계상수인 간극률로 변환하였으며 이를 통해 지층의 간극률 주상도를 제시하였다. 또한 신뢰성을 검토하기 위해 각 측선마다 표준관입실험도 함께 실시하여 데이터를 비교하였으며, 그 결과 분석된 간극률 값과 유사한 경향성을 보였다. 지구통계학 활용시 결과값에 영향을 주는 확률통계함수의 영향에 대한 고찰도 함께 실시하였으며 충적층 지역에서는 그 영향 정도가 작게 나타났다.

충남 부여 군수리 일대 충적층의 퇴적구조

박지훈 ( Ji Hoon Park ) 한국지리학회 2014 한국지리학회지 Vol.3 No.1

In this study, with the object of alluvial plain in the whole area (hereinafter referred as the research area) of Gunsu-ri, Buyeo Chungnam Province we carried out facies analysis and stratigraphic analysis of the alluvium based on field work and preceding study materials to investigate the sedimentary structure of the alluvium in the research area. The result is like the following. ① It was confirmed that various alluvial geographical features formed over the Last Interglacial~Holocene are revealed on the current ground or buried under the ground in the research area. ② It was confirmed that clay layer(brown and yellow) and organic clay layer(grayish blue~charcoal gray) are deposited in the buried small valley formed dissected terrace gravel responding to the period of low sea level of the Last Glacial in the river terrace(formed in the Last Interglacial). ③ In the point bar(formed in Holocene), buried alluvial island, natural levee and back marsh were found. ④ Especially in terms of sequence of strata, the above-mentioned organic clay layer is naturally connected with ‘Baekje period paddy field layer’ buried in the research area. It means it is highly likely that the back marsh of Geumgang River distributed in the research area were partially used as farmland in Baekje period.

충적대수층 조사를 위한 모래와 점토의 유도분극 특성 고찰

최상혁 ( Sang Hyuk Choi ),김형수 ( Hyoung Soo Kim ),김지수 ( Ji Soo Kim ) 대한지질공학회 2008 지질공학 Vol.18 No.4

충적층의 구성물질 중에서 포화된 실트 또는 점토층은 다른 층들에 비해 상대적으로 낮은 전기비저항 값을 나타낸다. 따라서 자료해석에 있어서 실트 및 점토층이 전기비저항이 작고 투수성이 높은 대수층으로 오인될 수 있다. 본 연구에서는 이러한 문제를 극복하고 충적층 내 포화된 실트 또는 점토층과 모래 또는 자갈 대수층을 구분하기 위해 충적층을 구성하고 있는 물질의 전기비저항 및 유도분극 값을 함께 측정하는 실내실험을 실시하였다. 실험결과 실트 또는 점토시료가 모래시료보다 충전성이 높게 나타났으며, 또한 모래와 점토 혼합시료에서 점토함량이 증가함에 따라 전기비저항은 감소하고 충전성은 증가하다가 다시 감소하는 경향을 보였다. In general, water-saturated silt or clay alluvium is characterized with relatively low-resistivity. Thus we often encountered the problem that such a low-resistivity layer is misguided to be good aquifer of high-permeability and low-resistivity in the development of groundwater. This research was conducted with an emphasis on the identification of saturated silt or clay layer from the aquifer by performing the laboratory experiment of IP and resistivity methods on the various materials consisting of alluvium aquifer. Silt or clay layer is found to be characterized with the higher chargeability zone, compared to the sand layer. Regarding the mixture of sand and clay, the higher clay volume, the lower resistivity and the higher chargeability. Subsequently chargeability decreases.

Riverbank Filtration Well Development for a Heat Source/Sink of Ground Water Heat Pumps

조용(Cho, Yong),이남영(Lee, Nam Young),이송이(Lee, Song Ee),문종필(Moon, Jong-Pil) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

Riverbank filtration wells have been developed to supply a heat source/sink of water in the alluvium aquifer to ground water heat pumps for cooling and heating of a green house. In order to look for an appropriate site to carry out the research, two sites of Jinju and Gumi areas were investigated. In the results of the electrical resistivity surveys, Jinju and Gumi areas have the alluvium aquifer in the depth of 6~17 m and 10~20 m under the ground respectively. Two boreholes have been drilled in each site of both areas. The averaged water level at Jinju site is about 3 m under the ground, and 3.5 m and 6.5 m of sandy gravel aquifer layers are existed in each site. While Gumi site has 10 m water level and 2.5 m and 4.6 m of sandy gravel aquifer. Therefore, it is expected that 1,000m³/day of water could be withdrawn at Jinju site rather than Gumi site.

충남 공주 제민평야 충적층의 퇴적구조

박지훈 ( Ji Hoon Park ),이애진 ( Ae Jin Lee ) 한국지형학회 2015 한국지형학회지 Vol.22 No.2

This study investigated the sedimentary structure of the Jemin Plain alluvial (17.2~31.5 m a.s.l.), developed in the whole area of the Jemin Stream banks in Gongju, Chungnam. The research was done by carrying out facies analysis, grain size analysis, radiocarbon dating and stratigraphic interpretation of the Plain`s trench materials and exploratory holes drilled on the alluvial plain. Results showed that the thickness of the Plain alluvial was between 2.2 and 14 m. Furthermore, the altitude above sea level of the river bed (buried valley bottom) in the coldest period of the Last Glacial of the Jemin Stream (a tributary of the Geum River) was found to between 3.2 and 28 m. The alluvium of the Plain was largely classified into the Lower layer, the Middle layer and the Upper layer. The Lower layer was composed of gravel in the most part and of a thin layer of peat. This basal gravel layer was deposited in the coldest period of the Last Glacial. The Middle layer mostly consisted of silt and contained a sandy gravel layer, an organic layer and a cultural layer. The Middle layer was formed by flooding in the Post-Glacial age. The Upper layer was mostly composed of silty sand and also contained a sandy silt layer and a buried layer. These silty sand and sandy silt layers were formed by flood and mass movement after the longitudinal profile of the Jemin Stream reached an equilibrium state in the late Post-Glacial age. The buried layer was an artificially dumped layer made to reduce damages caused by river flooding in the modern ages.

A Study on Optimal Site Selection for the Artificial Recharge System Installation Using TOPSIS Algorithm

이재원,서민호 한국측량학회 2016 한국측량학회지 Vol.34 No.2

This paper is intended to propose a novel approach to select an optimal site for a small-scaled artificial recharge system installation using TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) with geospatial data. TOPSIS is a MCDM (Multi-Criteria Decision Making) method to choose the preferred one of derived alternatives by calculating the relative closeness to an ideal solution. For applying TOPSIS, in the first, the topographic shape representing optimal recovery efficiency is defined based on a hydraulic model experiment, and then an appropriate surface slope is determined for the security of a self-purification capability with DEM (Digital Elevation Model). In the second phase, the candidate areas are extracted from an alluvial map through a morphology operation, because local alluvium with a lengthy and narrow shape could be satisfied with a primary condition for the optimal site. Thirdly, a shape file over all candidate areas was generated and criteria and their values were assigned according to hydrogeologic attributes. Finally, TOPSIS algorithm was applied to a shape file to place the order preference of candidate sites.