Journal of the Korean Association of Geographic Information Studies (한국지리정보학회지)

The Korean Association of Geographic Information Studies (한국지리정보학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of the Accuracy of IMERG at Multiple Temporal Scales

시간 해상도 변화에 따른 IMERG 정확도 평가

  • KIM, Joo-Hun (Dept. of Hydro Science and Engineering Research, KICT) ;
  • CHOI, Yun-Seok (Dept. of Hydro Science and Engineering Research, KICT) ;
  • KIM, Kyung-Tak (Dept. of Hydro Science and Engineering Research, KICT)
  • 김주훈 (한국건설기술연구원 수자원.하천연구소) ;
  • 최윤석 (한국건설기술연구원 수자원.하천연구소) ;
  • 김경탁 (한국건설기술연구원 수자원.하천연구소)
  • Received : 2017.11.15
  • Accepted : 2017.12.19
  • Published : 2017.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

The purpose of this study was the assessment of the accuracy of Global Precipitation Measurement (GPM) Integrated Multi-Satellite Retrievals for GPM (IMERG), a rainfall data source derived from satellite images, for evaluation of its applicability to use in ungauged or inaccessible areas. The study area was the overall area of the Korean peninsula divided into six regions. Automated Surface Observing System (ASOS) rainfall data from the Korean Meteorological Administration and IMERG satellite rainfall were used. Their average correlation coefficient was 0.46 for a 1-h temporal resolution, and it increased to 0.69 for a 24-h temporal resolution. The IMERG data quantitatively estimated less than the rainfall totals from ground gauges, and the bias decreased as the temporal resolution was decreased. The correlation coefficients of the two rainfall events, which had relatively greater rainfall amounts, were 0.68 and 0.69 for a 1-h temporal resolution. Additionally, the spatial distributions of the ASOS and IMERG data were similar to each other. The study results showed that the IMERG data were very useful in the assessment of the hydro-meteorological characteristics of ungauged or inaccessible areas. In a future study, verification of the accuracy of satellite-derived rainfall data will be performed by expanding the analysis periods and applying various statistical techniques.

본 연구는 위성으로부터 유도된 강우자료 중 GPM IMERG의 정확도를 평가함으로써 미계측 혹은 비접근 지역에 대한 적용성을 판단하는 것을 목적으로 하였다. 연구대상 유역은 한반도 전역에 대하여 6개 권역으로 구분하여 분석을 수행하였다. 연구 유역에 대한 강우자료는 기상청에서 생산하고 있는 ASOS의 강우량 자료와 IMERG 위성강우자료를 이용하였다. 1시간의 시간해상도에서 평균 0.46의 상관계수를 가지며 24시간 해상도의 상관분석에서는 0.69로 높은 상관관계를 보이는 것으로 분석되었다. IMERG 강우량은 지상계측 강우량 보다 과소추정되는 것으로 분석되었으나, 시간 해상도가 낮아질수록 편이가 감소하는 것으로 분석되었다. 한편, 강우가 큰 기간의 사상 2개를 선정하여 분석한 결과 1시간 해상도의 상관계수는 0.68 및 0.69 값을 나타내었다. 또한 강우의 공간분포도 ASOS 및 IMERG 모두 유사한 분포를 보이는 것으로 분석되었다. 그러므로 IMERG 자료는 계측자료가 부족하거나 접근이 어려운 지역에서의 수문 기상 특성을 파악하는데 매우 유용할 것으로 판단된다. 향후 연구에서는 분석기간의 확장과 다양한 통계 분석 방법을 적용하여 위성강우의 정확도를 검증하는 연구를 수행할 계획이다.

Keywords

References

  1. Alemseged, T.H., E. Habib, and T. Rientjes. 2013. Evaluation of the climate prediction center (CPC) morphing technique (CMOR PH) rainfall product on hourly time scales over the source of the Blue Nile River. Hydrological Process 27(2):1829-1839. https://doi.org/10.1002/hyp.9330
  2. Apip, K.T., Y. Yamashiki, K. Sassa, A.B. Ibrahim, and H. Fukuoka. 2010. A distributed hydrological-geotechnical model using satellite-derived rainfall estimates for shallow landslide prediction system at a catchment scale. Landslides 7(3):237-258. https://doi.org/10.1007/s10346-010-0214-z
  3. Bang, S.W. 2015. Let's focus water industry in North Korean. Korea River Association 11:6-7 (방승우. 2015. 북한물산업에 관심을 갖자. 한국하천협회 Vol.11 pp.6-7.)
  4. Immerzeel 2010. Bias correction for satellite precipitation estimation used by the MRC Mekong flood forecasting system. Mekong River Commission Mission report. Available at: http://www.futurewater.nl/projects/bias-correction-precipitation/(Accessed April 5, 2017).
  5. Owen, K. 2016. The IMERG multi-satellite precipitation estimates reformatted as 2-byte TIFF files for display in Geographic Information Systems (GIS). Available at: https://pps.gsfc.nasa.gov/Documents/README.GIS.pdf (Accessed May 14, 2016).
  6. Kim, K.T. and J.H. Kim. 2013. Introduce for case study of rainfall observations and application using satellite. Magazine of Korea Water Resources Association (Water for Future) 46(4):66-75 (김경탁, 김주훈. 2013. 인공위성을 이용한 강우관측자료 및 활용 사례 소개. 한국수자원학회지 46(4):66-75).
  7. Kim, J.H., K.T. Kim, and Y.S. Choi. 2013. Fitness evaluation of CMORPH satellite -derived precipitation data in Korea. Journal of Wetlands Research 15(3):339-346 (김주훈, 김경탁, 최윤석. 2013. 한반도의 CMORPH 위성강수자료 정확도 평가. 한국습지학회 논문집 15(3):339-346). https://doi.org/10.17663/JWR.2013.15.3.339
  8. Kim, J.H., Y.S. Choi, and K.T. Kim. 2017. Estimation of flood discharge using satellite-derived rainfall in abroad watersheds -a case study of Sebou watershed, Morocco. Journal of the Korean Association of Geographic Information Studies 20(3):141-152 (김주훈, 최윤석, 김경탁. 2017. 위성 강우자료를 이용한 해외 유역 홍수량 추정 -모로코 세부강 유역을 대상으로. 한국지리정보학회지 20(3):141-152). https://doi.org/10.11108/KAGIS.2017.20.3.141
  9. Namgung, D. and S.H. Lee. 2014. Introduction of upper Trishuli 1 hydropower project in Nepal. The Magazine of the Korea Society of Civil Engineers 62(6): 57-60 (남궁돈, 이상화. 2014. 네팔 수력발전 사업 소개. 대한토목학회 62(6):57-60).
  10. Pereira Filho, A.J., R.E. Carbone, J.E. Janowiak, P. Arkin, R. Joyce, R. Hallak, and C.G.M. Ramos. 2010. Satellite rainfall estimates over South America - possible applicability to the water management of large watersheds. Journal of the American Water Resources Association 46(2):344-360. https://doi.org/10.1111/j.1752-1688.2009.00406.x
  11. Sohn, B.J., H.J. Han, and E.K. Seo. 2010. Validation of satellite - based highresolution rainfall products over the Korean Peninsula using data from a dense rain gauge network. Journal of Applied Meteorology and Climatology 49(4):701-714. https://doi.org/10.1175/2009JAMC2266.1
  12. Xie, P, S.H. Yoo, R. Joyce, and Y. Yarosh. 2011. Bias-corrected CMORPH: a 13-year analysis of high-resolution global precipitation. NOAA's Climate Prediction Center (presentation). Available at: http://ftp.cpc.ncep.noaa.gov/precip/CMORPH_V1.0/REF/EGU_1104_Xie_bias-CMORPH.pdf (Accessed May 3, 2016).