• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.263-266
• /
• 2003

균열암반내의 수리적 유동 특성을 파악하기 위하여 다양한 물리검층을 수행하였다. 물리검층법은 시추공 주변 지층이나 공내수의 물리적 또는 유동 특성의 연속적인 측정이 가능한 장점을 지니고 있어 최근 지하수 조사나 환경오염 분야에 활용이 점점 증가하는 추세이다. 본 연구는 균열 암반내에서 지하수의 유동 특성 파악에 효과적인 Heat-pulse type의 유향ㆍ유속검층을 이용하여 시추공과 교차하는 파쇄대의 수리적인 연결 특성을 파악하였다. 특히, 양수를 병행하면서 취득한 유향ㆍ유속검층 자료는 시추공내로 지하수가 유입 또는 유출되는 구간을 정확하게 파악할 수 있었다. 이들 결과는 지하수 수치모델 설정, 각종 공내 수리시험 등에 중요한 정보를 제공할 수 있을 것으로 기대된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.509-513
• /
• 2004

현장 균열망의 연결성 및 이에 따른 수리지질학적 특성을 규명하기 위하여, 기존의 통상적인 조사 기법을 한 지역에 집적하여 그 결과에 대한 통합해석을 수행하였다. 본 연구에 적용된 조사 방법은 양수시험, 물리검층, 다중심도 수리화학 분석, 전기비저항 토모그래피, 시추 코어 검층 등의 기련 특성 조사와, 추적자 시험, 다중 심도 수직 유향유속 시험 등 구간별 특성 조사 등이다. 이러한 조사 결과 본 조사 지역 내 균열의 전반적인 분포 특성을 확인할 수 있었으며, 각 균열의 수리적 특성에 대한 기본적 특성을 확인할 수 있었다. 특히 추적자 시험과 유향유속 시험 결과를 통해 각 관정간의 균열을 통한 연결성에 대한 중요한 정보를 도출할 수 있었다. 이러한 성과는 추후 percolation, connectivity 등 모델 개념의 현장화를 위한 연구의 선행 연구로서 그 의미를 자리매김 할 수 있을 것이다.

• The Journal of Engineering Geology
• /
• v.21 no.1
• /
• pp.45-55
• /
• 2011

We examined the interactions between surface and groundwater through (1) flowmeter logging, (2) measurements of seasonal and vertical changes in temperature within a well, and (3) geochemical analyses of water samples from nine groundwater-monitoring wells. At two wells adjacent to a stream, subsurface water was found to flow from the stream to a surrounding alluvial fan, and the seasonal change in groundwater temperature is similar to those of surface water and air. Geochemical analyses at two wells indicated hydro-geochemical features affected by streamwater inflow, showing seasonal variations. Accordingly, these two wells are located in an area with active interaction between surface water and groundwater. The Thermochron I-button used in the present study is useful for this type of study of groundwater?surface water interaction because of its low cost and small size.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.09a
• /
• pp.55-71
• /
• 2005

Jeju Island is mainly composed of basaltic lava flows and subordinate amounts of volcaniclastic sedimentary rocks. Jeju Province operates the monitoring wells for seawater intrusion problems around Jeju Island to evaluate of groundwater resources in coastal area. Various surveys and monitoring have been performed in boreholes, and also conventional geophysical well loggings conducted to identify basalt sequences and assess seawater intrusion problems. Various conventional geophysical well logs, including radioactive logs, electrical log, caliper log, and temperature and conductivity log and heat-pulse flowmeter log were obtained in 29 boreholes. The results of geophysical well loggings for saturated rocks are interesting and consistent. Natural gamma logs are useful in basalt sequences to sedimentary interbeds, unconsolidated U formation, and seoguipo formation with higher natural gamma log regardless of saturated or unsaturated basalts. Neutron logs are very effective to discriminate among individual lava flows, flow breaks, and sedimentary interbeds in saturated formation. In hyalocastite, porosity is high and resistivity is low, and we think that hyalocastite is a major pathway of fluid flow. In trachybasalt, porosity has a wide range and resistivity is high. In sedimentary interbeds, unconsolidated U formation and seoguipo formation, porosity is high and resistivity is low. The temperature logs in eastern area in Jeju are useful to interpret the hydrogeological unit and evaluate seawater intrusion in Suan area.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.4
• /
• pp.33-44
• /
• 2005

On the basis of a stepwise and careful integration of various field and laboratory methods the analysis of groundwater flow characterization was performed with five boreholes (BH-1, -2, -3, -4, -5) on a pilot site of Natural Forest Park in Guemsan-gun, Chungcheongbook-do, Korea. The regional lineaments of NW-SE are primarily developed on the area, which results in the development of many fractures of NW-SE direction around boreholes made in the test site for the study. A series of surface geological survey, core logging, geophysical logging, tomography, tracer tests, and heat-pulse flowmeter logging were carried out to determine fracture characteristics and fracture connectivity between the boreholes. In the result of fracture connectivity analysis BH-1 the injection well has a poor connectivity with BH-2 and BH-3, whereas a good with BH-4 and BH-5. In order to analyse the hydraulic connectivity between BH-1 and BH-5, in particular, a conspicuous groundwater outflux in the depth of 12 m and influx in the depth of 65 m and 70 m, but partly in/outflux occurred in other depths in BH-5 were observed as pumping from BH-1. On the other hand, when pumping from BH-5 the strong outflux in the depths of 17 m and 70 m was occurred. The spatial connectivity between the boreholes was examined in the depth of 15 m, 67 m, and 71 m in BH-1 as well as in the depth of 15 m, 17 m, 22 m, 72 m, and 83 m in BH-5.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.271-275
• /
• 2005

The horizontal heat-pulse flowmeter was used to measure grounwater flow in volcanic rocks at sites in eastern part of Jeju Island, Korea. Three boreholes, Handong-1, Jongdal-1, and Susan-1, which are located at close distance from the coastline, were selected from the sea water intrusion monitoring wells. To evaluate the direction and velocity of the groundwater flow, 6 to 8 measuring points for each borehole were chosen. There are two major flow directions at Handong-1, which are toward north-east and south-east directions and velocity ranges from $2.2{\sim}3.0cm/hr\;and\;0.6{\sim}1.0cm/hr$, respectively. For Jongdal-1, two major flow directions were detected that are east and north-west and velocity ranges from $1.2{\sim}2.0cm/hr$. For Susan-1, major flow is toward east direction and the ,velocity ranges from $2.2{\sim}2.7cm/hr$ at depth $60{\sim}70m$,\;and\;0.8{\sim}0.9cm/hr$ at depth $70{\sim}80m$. In order to evaluate the tidal effect on groundwater flow, direction and velocity were measured at specific depth with time, At depth 57m of Susan-1, the velocity increased during the tidal variation, The flow direction and velocity varies with different depths, and they are also affected by tidal fluctuation. Thereafter, care must be taken when flow direction and velociy is estimated indirectly by using hydraulic head at monitoring wells.