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Quantitative Comparison of Univariate Kriging Algorithms for Radon Concentration Mapping

라돈 농도 분포도 작성을 위한 단변량 크리깅 기법의 정량적 비교

  • KWAK, Geun-Ho (Department of Geoinformatic Engineering, Inha University) ;
  • KIM, Yong-Jae (Department of Natural Radiation Safety, Korea Institute of Nuclear Safety) ;
  • CHANG, Byung-Uck (Department of Natural Radiation Safety, Korea Institute of Nuclear Safety) ;
  • PARK, No-Wook (Department of Geoinformatic Engineering, Inha University)
  • 곽근호 (인하대학교 공간정보공학과) ;
  • 김용재 (한국원자력안전기술원 생활방사선안전실) ;
  • 장병욱 (한국원자력안전기술원 생활방사선안전실) ;
  • 박노욱 (인하대학교 공간정보공학과)
  • Received : 2017.01.06
  • Accepted : 2017.02.15
  • Published : 2017.03.31

Abstract

Radon, which enters the interior environment from soil, rocks, and groundwater, is a radioactive gas that poses a serious risk to humans. Indoor radon concentrations are measured to investigate the risk of radon gas exposure and reliable radon concentration mapping is then performed for further analysis. In this study, we compared the predictive performance of various univariate kriging algorithms, including ordinary kriging and three nonlinear transform-based kriging algorithms (log-normal, multi-Gaussian, and indicator kriging), for mapping radon concentrations with an asymmetric distribution. To compare and analyze the predictive performance, we carried out jackknife-based validation and analyzed the errors according to the differences in the data intervals and sampling densities. From a case study in South Korea, the overall nonlinear transform-based kriging algorithms showed better predictive performance than ordinary kriging. Among the nonlinear transform-based kriging algorithms, log-normal kriging had the best performance, followed by multi-Gaussian kriging. Ordinary kriging was the best for predicting high values within the spatial pattern. The results from this study are expected to be useful in the selection of kriging algorithms for the spatial prediction of data with an asymmetric distribution.

토양, 암석, 지하수로부터 실내에 유입되는 라돈은 인간에게 큰 위해를 끼치는 방사능 가스이다. 라돈 가스의 위해성을 확인하기 위해 실내 라돈 농도를 측정해 오고 있는데, 추가적인 분석 수행을 위해서는 신뢰성 높은 분포도 작성이 매우 중요하다. 본 연구에서는 비대칭 분포를 나타내는 라돈 농도의 공간 분포도 작성을 위해 단변량 크리깅 기법들의 비교를 목적으로 정규 크리깅, 비선형 자료 변환 기반의 로그 정규 크리깅, 다중 가우시안 크리깅과 지시자 크리깅의 예측 능력을 비교하였다. 예측 능력을 비교 분석하기 위해 잭나이프 방법을 이용하여 검증을 수행하였으며, 자료 구간별 오차와 샘플링 밀도의 차이에 따른 오차도 추가적으로 분석하였다. 남한 지역을 대상으로 한 사례 연구 결과에서 전반적으로 정규 크리깅에 비해 비선형 자료 변환 기반 크리깅 기법들이 좋은 예측 능력을 보였으며, 비선형 자료 변환 기반 크리깅은 로그 정규 크리깅, 다중 가우시안 크리깅 순으로 좋게 나타났다. 그러나 공간 패턴과 높은 값의 재생산을 고려할 때, 높은 값의 예측 능력은 정규 크리깅이 가장 우수하였다. 본 연구의 결과는 비대칭 분포 자료의 공간 예측을 위한 크리깅 기법의 선정에 유용하게 사용될 것으로 기대된다.

Keywords

References

  1. Baek, S.A., T.J. Lee, S.D. Kim, and D.S. Kim. 2008. Studies on the spatial analysis for distribution estimation of radon concentration at the seoul area. Journal of Korean Society for Atmospheric Environment 24(5):538-550 (백승아, 이태정, 김신도, 김동술. 2008. 서울지역 라돈농도의 분포예측을 위한 공간분석법 연구. 한국대기환경학회지 24(5):538-550). https://doi.org/10.5572/KOSAE.2008.24.5.538
  2. Bossew, P., Z.S. Zunic, Z. Stojanovska, T. Tollefsen, C. Carpentieri, N. Veselinovic, S. Komatina, J. Vaupotic, R.D. Simovic, S. Antignani, and F. Bochicchio. 2014. Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia-application of geostatistical methods. Journal of Environmental Radioactivity 127:141-148. https://doi.org/10.1016/j.jenvrad.2013.09.015
  3. Buttafuoco, G., A. Tallarico, and G. Falcone. 2007. Mapping soil gas radon concentration: a comparative study of geostatistical methods. Environmental Monitoring and Assessment 131(1-3):135-151. https://doi.org/10.1007/s10661-006-9463-7
  4. Cha, D.W. 2001. A study on mitigation methods of indoor radon concentration in residential buildings(I) - test cell study. Korea Institute of Ecological Architecture and Environment 1(2):21-28 (차동원. 2001. 주거용 건축물의 실내 라돈농도 경감방안에 관한 연구(I) - test cell study. 한국생태환경건축학회 논문집 1(2):21-28).
  5. Deutsch, C.V. and A.G. Journel. 1998. Geostatistical software library and user's guide. Oxford University Press, New York. U.S.. pp.63-86.
  6. Drolet, J.P., R. Martel, P. Poulin, J.C. Dessau, D. Lavoie, M. Parent, and B. Levesque. 2013. An approach to define potential radon emission level maps using indoor radon concentration measurements and radiogeochemical data positive proportion relationships. Journal of Environmental Radioactivity 124:57-67. https://doi.org/10.1016/j.jenvrad.2013.04.006
  7. Dubois, G. 2005. An overview of radon surveys in europe. Institute for Environment and Sustainability. European Commission. pp.2-9.
  8. EPA(Environmental Protection Agency). 1992. Technical support document for the 1992 citizen's guide to radon, U.S.. pp.1-3.
  9. Goovaerts, P. 1997. Geostatistics for natural resources evaluation. Oxford University Press, New York, U.S.. pp.265-328.
  10. Goovaerts, P. 2009. AUTO-IK: a 2D indicator kriging program for the automated non-parametric modeling of local uncertainty in earth sciences. Computers and Geosciences 35(6):1255-1270. https://doi.org/10.1016/j.cageo.2008.08.014
  11. Green, B.M.R., R. Larmour, J.C.H. Miles, D.M. Rees, and F.K. Ledgerwood. 2009. Radon in dwellings in Northern Ireland: 2009 review and atlas. Northern Ireland Environment Agency, Chilton, Oxon, U.K.. pp.21-26.
  12. Harman, B.I., H. Koseoglu, and C.O. Yigit. 2016. Performance evaluation of IDW, kriging and multiquadric interpolation methods in producing noise mapping: a case study at the city of Isparta, Turkey. Applied Acoustics 112:147-157. https://doi.org/10.1016/j.apacoust.2016.05.024
  13. Jacquez, G.M., P. Goovaerts, A. Kaufmann, and R. Rommel. 2014. SpaceStat 4.0 user manual: software for the spacetime analysis of dynamic complex systems. BioMedware, Washington, U.S., pp.419-440.
  14. Kim, Y.J., B.U. Chang, H.M. Park, C.K. Kim, and S. Tokonami. 2011. National radon survey in Korea. Radiation Protection Dosimetry 146(1-3):6-10. https://doi.org/10.1093/rpd/ncr094
  15. Lee, H.S. 2010. Comparison and evaluation of root mean square for parameter settings of spatial interpolation method. Journal of the Korean Association of Geographic Information Studies 13(3):29-41 (이형석. 2010. 공간보간법의 매개변수 설정에 따른 평균제곱근 비교 및 평가. 한국지리정보학회지 13(3):29-41).
  16. Park, H.J., H.S. Shin, Y.H. Roh, K.M. Kim, and K.H Park. 2012. Estimating forest carbon stocks in Danyang using kriging methods for aboveground biomass. Journal of the Korean Association of Geographic Information Studies 15(1):16-33 (박현주, 신휴석, 노영희, 김경민, 박기호. 2012. 크리깅 기법을 이용한 단양군의 산림 탄소저장량 추정 -지상부 바이오매스를 대상으로-. 한국지리정보학회지 15(1):16-33). https://doi.org/10.11108/kagis.2012.15.1.016
  17. Park, J.C. and M.K. Kim. 2013. Comparison of precipitation distributions in precipitation data sets representing 1km spatial resolution over South Korea produced by PRISM, IDW, and cokriging. Journal of the Korean Association of Geographic Information Studies 16(3):147-163 (박종철, 김만규. 2013. PRISM, 역거리가중법, 공동크리깅으로 작성한 1km 공간해상도의 남한 강수 자료에서 강수 분포의 비교. 한국지리정보학회지 16(3):147-163). https://doi.org/10.11108/kagis.2013.16.3.147
  18. Park, N.W. 2009. Comparison of univariate kriging algorithms for GIS-based thematic mapping with ground survey data. Korean Journal of Remote Sensing 25(4):321-338 (박노욱. 2009. 현장 조사 자료를 이용한 GIS 기반 주제도 작성을 위한 단변량 크리깅 기법의 비교. 대한원격탐사학회지 25(4): 321-338). https://doi.org/10.7780/kjrs.2009.25.4.321
  19. Pasztor, L., K.Z. Szabo, G. Szatmari, A. Laborczi, and A. Horvath. 2016. Mapping geogenic radon potential by regression kriging. Science of the Total Environment 544:883-891. https://doi.org/10.1016/j.scitotenv.2015.11.175
  20. Saito, H. and P. Goovaerts. 2000. Geostatistical interpolation of positively skewed and censored data in a dioxin-contaminated site. Environmental Science and Technology 34(19):4228-4235. https://doi.org/10.1021/es991450y
  21. Smethurst, M.A., T. Strand, A.V. Sundal, and A.L. Rudjord. 2008. Large-scale radon hazard evaluation in the Oslofjord region of Norway utilizing indoor radon concentrations, airborne gamma ray spectrometry and geological mapping. Science of the Total Environment 407: 379-393. https://doi.org/10.1016/j.scitotenv.2008.09.024
  22. Webster, R. and M.A. Oliver. 2007. Geostatistics for environmental scientists. John Wiley & Sons, Ltd, West Sussex, U.K.. pp.153-193.