저수지 전기비저항 모니터링에서의 온도효과 = Temperature Effects in the Resistivity Monitoring at Embankment Dams

다국어 초록 (Multilingual Abstract)

Resistivity monitoring data at embankment dams are affected by the seasonal temperature variation. Especially when the seasonal temperature variation is large like Korea, the temperature effects may not be ignored in the longterm resistivity monitoring. Therefore, temperature effects can make it difficult to accurately interpret the resistivity monitoring data. In this study, through analyzing the time series of ground temperature collected at an embankment dam, ground temperature variations are calculated approximately. Then, based on the calculated temperature profile with depth, the inverted resistivity model of the embankment dam is corrected to remove the temperature effects. From these corrections, it was confirmed that the temperature effects are significant in the upper, superficial part of the dam, but can be ignored at depth. However, temperature correction based only on the temperature distribution in the dam body cannot remove the temperature effect thoroughly. To overcome this problem, the effect of temperature variation in the reservoir water seems to be incorporated together with the air temperature variation.

국문 초록 (Abstract)

저수지 안전진단을 위하여 수행되는 전기비저항 모니터링 자료는 대기의 온도에 영향을 받는다. 특히 국내와 같이 사계절의 온도 변화가 큰 환경에서는 지중온도 변화에 의한 전기비저항의 변화를 무시하기 어렵다. 따라서 온도효과는 전기비저항 모니터링 자료의 정밀한 해석을 어렵게 한다. 이 연구에서는 저수지에서 획득된 다점온도 모니터링 자료를 분석하여 시공간적 지중온도를 추정하고, 이를 이용하여 역산 결과 얻어진 지하 전기비저항 모델에 대하여 온도보정을 수행하였다. 온도보정 결과, 계절변화에 의한 온도 효과는 주로 상부에 국한되며, 심부에서는 무시할 수 있는 것으로해석되었다. 그러나 댐 제체의 온도 분포만을 가지고 온도 보정을 수행하면 그 효과를 완전히 제거할 수 없다. 이 문제를 극복하기 위해, 저수지 물의 온도 변화에 의한 효과는 대기온도 변화도 함께 포함되어야 할 것으로 보인다.

참고문헌 (Reference)

1 윤종렬, "하천제방의 안전성 평가를 위한 전기비저항탐사" 대한지구물리학회 8 (8): 53-61, 2005

2 조인기, "전기비저항 상시관측에 의한 제체 안전도 지수 산출" 한국물리탐사학회 9 (9): 155-162, 2006

3 박삼규, "저수지의 유지관리를 위한 전기비저항모니터링 기법 응용" 한국물리탐사학회 8 (8): 177-183, 2005

4 조인기, "저수지 3차원 구조에 의한 전기비저항 탐사자료의 왜곡" 한국물리탐사학회 9 (9): 291-298, 2006

5 Loke, M. H., "Time-lapse resistivity imaging inversion" 1999

6 Cho, I. K., "Time-lapse inversion of resistivity monitoring data at embankment dams" KSRM, KSEG 42-, 2017

7 Day-Lewis, F. D., "Time-lapse inversion of crosswell radar data" 66 : 1740-1752, 2002

8 Kim, K. J., "Time-lapse inversion of 2D resistivity monitoring data with soatially varying cross-model constraint" 72 : 114-122, 2011

9 Oldenborger, G. A., "Time-lapse ERT monitoring of an injection/withdrawal experiment in a shallow unconfined aquifer" 72 : F177-F188, 2007

10 Hayashi, M., "Temperature-electrical conductivity relation of water for environmental monitoring and geophysical data inversion" 96 : 119-128, 2004

11 Johansson, S., "Seepage monitoring in an earth embankment dam by repeated resistivity measurements" 1 : 229-247, 1996

12 Singha, K., "Saline tracer visualized with three-dimensional electrical resistivity tomography: Field- scale spatial moment analysis" 41 : W05023-, 2005

13 Salmon, G. M., "Research on geophysical methods of detecting seepage and piping in embankment dams with case studies of geophysical measurements at two Swedish Tailings dams" 2003

14 Kim, J. H., "Processing of ERT monitoring data and evaluation of their reliabilities" 2016

15 Titov, K., "Monitoring of water seepage from a reservoir using resistivity and self polarization methods: case history of the Petergoph fountain water supply system" 18 : 431-435, 2000

16 Sjodahl, P., "Monitoring of leakage in embankment dams through resistivity measurements - A 2.5D modeling study" 169-172, 2002

17 Hayley, K., "Low temperature monitoring dependence of electrical resistivity: Implications for near surface, geophysical monitoring" 34 : L18402-, 2007

18 Sen, P. N., "Influence of temperature on electrical conductivity on shaly sands" 57 : 89-96, 1992

19 Rein, A., "Influence of natural time-dependent variations of electrical conductivity on DC resistivity measurements" 285 : 215-232, 2004

20 Kemna, A., "Imaging and characterization of subsurface solute transport using electrical resistivity tomography (ERT) and equivalent transport models" 267 : 125-146, 2002

21 Butler, D. K., "Geotechnical and Environmental Geophysics II" SEG 1990

22 Ogilvy, A. A., "Geophysical studies of water leakages from reservoirs" 17 : 36-63, 1969

23 Kim, J. H., "Fourdimensional inversion of resistivity monitoring data through Lp norm minimizations" 195 : 1640-1656, 2013

24 Daily, W., "Electrical resistance tomography" 23 : 438-442, 2004

25 Revil, A., "Electrical conductivity in shaly sands with geophysical applications" 103 : 23;925-23;936, 1998

26 LaBrecque, D. J., "Difference inversion of ERT data, A fast inversion method for 3-D in-situ monitoring" 6 : 83-89, 2001

27 Chung, S. H., "Delineation of water seepage in earth-fill embankments by electrical resistivity method" 2 : 47-57, 1992

28 Cho, I. K., "Crossline resistivity tomography for the delineation of anomalous seepage pathways in an embankment dam" 72 : G31-G38, 2007

29 Hayley, K., "Compensating for temperature variations in time-lapse electrical resistivity difference imaging" 75 : WA51-WA59, 2010

30 Miller, C. R., "Application of time-lapse ERT imaging to watershed characterization" 73 : G7-G17, 2008

31 Song, S. H., "Application of hydrogeological and geophysical methods to leakage problem of dike" 38 : 292-300, 2001

32 송성호, "Application of hydrogeological and geophysical methods to delineate leakage pathways in an earth fill dam" 한국물리탐사학회 8 (8): 92-96, 2005

33 Park, S. G., "Applicability of geophysical prospecting for water leakage detection in water utilization facilities" 179-195, 2002

34 Oh, S. H., "Analysis of distortion effect of resistivity data due to 3D geometry of fill dam" 55-58, 2005

35 Deiana, R., "An experiment of non-invasive characterization of the vadose zone via water injection and cross-hole time-lapse geophysical monitoring" 5 : 183-194, 2007

36 Hermans, T., "A shallow geothermal experiment in a sandy aquifer monitored using electric resistivity tomography" 77 : B11-B21, 2012

37 Cassiani, G., "A saline trace test monitored via time-lapse surface electrical resistivity tomograph" 59 : 244-259, 2006

38 Slater, L., "A 3D study solute transport in a large experimental tank" 49 : 211-229, 2002

39 Karaoulis, M., "4D time-lapse ERT inversion: introducing combined time and space constraints" 12 : 25-34, 2014

40 Karaoulis, M., "4D active time constrained inversion" 73 : 25-34, 2011

41 Kim, J. H., "4-D inversion of DC resistivity monitoring data acquired over a dynamically changing earth model" 68 : 522-532, 2009

42 Cho, I. K., "3D effects on 2D resistivity monitoring in earth-fill dam" 12 : 73-81, 2014

43 Sjodahl, P., "2.5D resistivity modeling of embankment dams to assess influence from geometry and material properties" 71 : 107-114, 2006