KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
권호 표지
DOI QR코드

DOI QR Code

Estimating Evapotranspiration with the Complementary Relationship at Fluxnet Sites Over Asia

아시아 Fluxnet 자료를 활용한 보완관계 기반 증발산량 추정

  • 서호철 (연세대학교 토목환경공학과 통합과정) ;
  • 김정빈 (연세대학교 토목환경공학과) ;
  • 박혜선 (연세대학교 토목환경공학과) ;
  • 김연주 (연세대학교 토목환경공학과)
  • Received : 2016.12.21
  • Accepted : 2017.03.08
  • Published : 2017.04.01
Download PDF
⟨ Previous Next ⟩

Abstract

Evapotranspiration is a significant hydrologic quantity for understanding the amount of available water resource evaluation, water balance analysis, water circulation and energy circulation. Various methods have been developed for estimating the evapotranspiration using data observed at meteorological observatories. Especially, the focus of methods has been on the complementary relationship that the actual evapotranspiration is equal to the difference between the twice of evapotranspiration in the wet condition and the potential evapotranspiration. The Granger and Gary (GG) method is an empirical formula that can be used to estimate the evapotranspiration using only empirical parameters based on the complementary relationship and using only the net radiation and temperature of the region. In this study, we compared the evapotranspiration data observed at 10 sites in Asia within the dataset of FLUXNET2015, with the evapotranspiration calculated by GG method. The evapotranspiration in inland area was estimated more accurately than that of coastal area. Simulated Annealing (SA) was used for the coastal area to modify the parameters. Using the modified GG method, we could improve the statistics such as root mean square error, the coefficient of determination ($R^2$), and the mean absolute ${\mid}BIAS{\mid}$ of the evapotranspiration estimation in coastal area.

증발산량은 수자원 부존량 평가, 물수지 분석, 지구의 물 순환 및 에너지 순환을 이해하기 위해서 알아야 할 중요한 수문량이다. 실제 증발산량이 습윤조건의 증발산량의 2배에서 잠재 증발산량을 제한 것과 같다는 보완관계(Complimentary relationship)를 기반으로 기상관측망 지점에서 일반적으로 관측되는 기상 자료를 이용해 증발산량을 산정하는 방법이 다양하게 개발되어 왔다. 이 중 Granger and Gary (GG)방법은 보완관계를 기반으로 경험적인 매개변수를 도입하여, 지역의 기온 등의 자료만 활용하여 증발산량을 산정할 수 있도록 하는 경험식이다. 본 연구에서는 FLUXNET2015 자료 중 아시아 지역 내의 10개 지점에서 에디공분산법을 활용해서 관측된 증발산량 자료를 GG방법을 활용하여 산정한 증발산량과 비교하였다. 내륙지역의 경우 해안지역에 비해 상대적으로 정확하게 증발산량이 추정되었고, 이에 해안지역의 경우에만 담금질 기법(Simulated Annealing, SA)을 활용하여 GG방법의 매개변수를 수정하였다. 수정된 GG방법을 활용하여 증발산량 추정 결과의 Root mean square error, Coefficient of determination($R^2$), Mean absolute BIAS를 개선할 수 있었다.

Keywords

References

  1. Allen, R. G., Pereira, L. S., Raes, D. and Smith, M. (1998). "Crop evapotranspiration - guidelines for computing crop water requirements." FAO irrigation and drainage paper 56.
  2. Anayah, F. M. and Kaluarachchi, J. J. (2014). "Improving the complementary methods to estimate evapotranspiration under diverse climatic and physical conditions." Hydrology and earth system sciences, Vol. 18, pp.2049-2064. https://doi.org/10.5194/hess-18-2049-2014
  3. Aubinet, M., Vesala, T. and Papale, D. (2012). "Eddy covariance : A practical guide to measurement and data analysis." Springer Atmospheric Sciences, Springer Verlag.
  4. Badawy, H. A. (2009). "Effect of expected climate changes on evaporation losses from Aswan High Dam Reservoir (AHDR)." Thirteenth International Water Technology Conference, IWTC, Hurghada, Egypt.
  5. Baldocchi, D., Hicks, B. and Meyers, T. (1988). "Measuring biosphereatmosphere exchanges of biologically related gases with micrometeorological methods." Ecology, Vol. 69, pp. 1331-1340. https://doi.org/10.2307/1941631
  6. Bouchet, R. J. (1963). "Evapotranspiration reelle et potentielle, signification climatique." International Association of Hydrological Sciences Publication, Vol. 62, pp. 134-142.
  7. Granger, R. J. (1991). "Evaporation from natural nonsaturated surfaces." Ph.D. Thesis, Department of Agricultural Engineering, University of Saskatchewan, Saskatoon.
  8. Granger, R. J. and Gray, D. M. (1989). "Evaporation from natural nonsaturated surfaces." Journal of Hydrology, Vol. 111, pp. 21-29. https://doi.org/10.1016/0022-1694(89)90249-7
  9. Hargreaves, G. H. and Samani, Z. A. (1982). "Estimating potential evapotranspiration." Journal of the Irrigation and Drainage Division. Vol. 108, No. 3, pp. 225-230.
  10. Jeon, E. J., Kim, Y. H., Park, J. H. and Kim, M. P. (2013). "Development of forest carbon optimization program using simulated annealing heuristic algorithm." Journal of the Korea Society of Computer and Information, Vol. 18, No. 12, pp. 197-205 (in Korean). https://doi.org/10.9708/jksci.2013.18.12.197
  11. Jeon, J. W. and Lee, Y. H. (2005). "Iterative simulated annealing for graph coloring problem." Korean Institute of Industrial Engineering, pp. 226-229 (in Korean).
  12. Kim, N. W. and Lee, J. W. (2014). "Assessment of complementary relationship evapotranspiration models for the bokahcheon uppermiddle watershed." Journal of Korea Water Resources Association, Vol. 47, No. 6, pp. 547-559 (in Korean). https://doi.org/10.3741/JKWRA.2014.47.6.547
  13. Kirkpatrick, S., Gelatt, C. D. and Vecchi, M. P. (1983). "Optimization by simulated annealing." Science, Vol. 220, pp. 671-680. https://doi.org/10.1126/science.220.4598.671
  14. Kondoh, A. and Nishiyama, J. (2000). "Changes in hydrological cycle due to urbanization in the subrb of Tokyo Metropolitan area, Japan" Advances in Space Research, Vol. 26, No.7, pp. 1173-1176. https://doi.org/10.1016/S0273-1177(99)01143-6
  15. Lee, G. H. and Park, J. H. (2008). "Calibration of the hargreaves equation for the reference evapotranspiration estimation on a nationwide scale." Journal of the Korean Society of Civil Engineers, KSCE, Vol. 28, No. 6B, pp. 675-681 (in Korean).
  16. Liu, S., Sun, R., Sun, Z., Li, X. and Liu, C. (2006). "Evaluation of three complementary relationship approaches for evapotranspiration over the Yellow River basin." Hydrological processes, Vol. 20, pp. 2347-2361. https://doi.org/10.1002/hyp.6048
  17. Morton, F. (1983). "Operational estimates of areal evapotranspiration and their significance to the science and practice of hydrology." Journal of Hydrology, Vol. 66, pp. 1-76. https://doi.org/10.1016/0022-1694(83)90177-4
  18. Penman, H. L. (1948). "Natural evaporation from open water, bare soil and grass." Mathematical and Physical Sciences, Vol. 193, pp. 120-145. https://doi.org/10.1098/rspa.1948.0037
  19. Priestley, C. H. B. and Taylor, R. J. (1972). "On the assessment of surface heat flux and evaporation using large-scale parameters." Monthly Weather Review, Vol. 100, No. 2, pp. 81-92. https://doi.org/10.1175/1520-0493(1972)100<0081:OTAOSH>2.3.CO;2