Regionalization of CN values at Imha Watershed with SCE-UA

최적화 기법을 이용한 임하호유역 대표 CN값 추정

  • Received : 2011.07.28
  • Accepted : 2011.09.07
  • Published : 2011.09.30


Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.


  1. Donigian, Jr.A.S., 2002. Watershed model calibration and validation: The HSPF Experience. WEF Speciality Conference Proceedings, Phoenix, AZ. WEF National TMDL Science and Policy 2002.
  2. Duan, Q., S. Sorooshian, and V.K. Gupta, 1992. Effective and efficient global optimization for conceptual rainallrunoff models. Water Resource Research 28(4): 1015- 1031.
  3. Holland, J.H, 1975. Adaptation in natural and artificial systems, Univ. of Mich. Press, Ann Arbor, MI.
  4. Jeon, J.H., and B.A. Engel, 2011. Regional calibration of SCS-CN runoff model: Application for ungauged basin. Environmental Modelling & Software (submitted).
  5. Jeon, J.H., B.A. Engel, K.J. Lim, and C.G. Yoon, 2007. Effect of land use type and hydrologic soil group on SCS-CN uncertainty using Monte Carlo simulation. 7th International IWA Symposium on Systems Analysis and Integrated Assessment in Water Management, 7-9 May, 2007, Washington DC. USA.
  6. Jeon, N.J., C.G. Yoon, S.B. Lee, and Y.K. Son, 2010. Feasibility study of water quality prediction for agricultural reservoir using L-THIA Arcview GIS. 2010 Spring Conference Proceeding of Korean Society on Water Quality, 51-52.
  7. Kim, D.S., 2006. A study on the estimation of nonpoint source pollution source load using GIS and L-THIA models. M.S. Thesis, Daegue, Ind.: Yeungnam University (in Korean)
  8. Kim, J.G. Y.S. Park, J.H. Jeon, B.A. Engel, J.H. Ahn, Y.K. Park, K.S. Kim, J.D. Choi, and K.J. Lim, 2007a. Evaluation of L-THIA WWW direct runoff estimation with AMC adjustment. Journal of Korean Society on Water Quality 23(4): 474-481.
  9. Kim, J., K.J. Lim, Y. Park, S. Heo, J. Park, J. Ahn, K.S. Kim, and J. Choi, 2007b. The effect of slope-based Curve Number adjustment on direct runoff estimation by L-THIA. Journal of Korean Society on Water Quality 23(6): 897-905.
  10. Kim, J.J., T.D. Kim, D.H. CHoi, K.J. Lim, B.A. Engel, and J.H. Jeon, 2009. L-THIA modification and SCE-UA application for spatial analysis of nonpoint source pollution at Gumho River Basin. Journal of Korean Society on Water Quality 25(2): 311-321.
  11. Kim, J.G., Y.S. Park, J.W. Seok, R.J. Chul, H.W. Kang, K.S. Kim, J.D. Choi, and K.J. Lim, 2010. Comparison of estimated direct runoff using SWAT and L-THIA in the Doam-dam Watershed. The KCID Journal 17(1): 35-42.
  12. Kuczera, G., 1997. Efficient subspace probabilistic parameter optimization for catchment models. Water Resources Research 33(1):177-185.
  13. Lim, K.J., B.A. Engel, Y. Kim, B. Bhaduri, and J. Harbor, 2001. Development of Long-term Hydrologic Impact Assessment (L-THIA) WWW System. International Soil Conservation Organization in cooperation with the USDA and Purdue University, West Lafayette, Indiana.
  14. Nelder, J.A., and R. Mead, 1965. A simplex method for function minimization. Computer Journal 7: 308- 313.
  15. NRCS, 1985. Urban hydrology for small watersheds, 2-1. 210-VI-TR-55. Natural Resources Conservation Service, USDA,
  16. Park, S.W., 1997. Estimating runoff curve number for rice paddies and its application to watershed hydrology, 21-23. KOSEF 951-0601-002-2.
  17. Shin, M.H., J.A. Lee, S.U. Cheon, Y.J. Lee, K.J. Lim, and J.D. Choi, 2010. Analysis of the characteristics of NPS runoff and application of L-THIA model at upper Daecheong Reservoir. Journal of the Korean Society of Agricultural Engineers 52(1): 1-11.
  18. Yoon, R.Y. D.H. Kim, H.H. Kwon, S.C. Shin, and K.I. Son, 2006. Assessing the impact of urbanization on runoff and non-point source pollution using the GIS L-THIA. 2006 Annual Conference Proceeding of KWRA, 1802-1806.

Cited by

  1. Enhancement of Estimation Method on the Land T-P Pollutant Load in TMDLs Using L-THIA vol.36, pp.3, 2014,
  2. Probabilistic Analysis of Vertical Drains using Hasofer-Lind Reliability Index vol.53, pp.6, 2011,
  3. Experimental Evaluation of Synthesis Gas Production from Air Dried Woodchip vol.53, pp.6, 2011,
  4. Analysis of Spatical Distribution of Surface Runoff in Seoul City using L-THIA: Case Study on Event at July 27, 2011 vol.53, pp.6, 2011,
  5. Spatial Analysis of Nonpoint Source Pollutant Loading from the Imha dam Watershed using L-THIA vol.55, pp.1, 2013,