عنوان مقاله [English]
The Curve Number (SCS-CN) method, one of the most widely used methods for estimating runoff in hydrology, has been developed by soil conservation services. The application of SCS equation in Iran may be mixed with considerable errors due to different climatological, geological, and hydrological characteristics. In addition, the other cause of error in this method is the relationship between Ia and S (Equation 2), which is experimental and has been taken from rainwater data in small laboratories (Anonymous, 1972). This relationship can be criticized in terms of the document and was examined in various studies of its accuracy and application (Bo et al., 2011, Shi et al., 2009, Baltas et al., 2007, Mishra et al ., 2006,2004, Hawkins et al., 2002), In order to calibrate the SCS equation and evaluation in empirical relations, Pasekohak catchment was selected. Pasekohak basin includes four sub-basins where flood runoff was gauged during five flood events. Curve Number (CN) for the sub-basins was estimated according to the remote sensing, geological maps, and field works. The real hydrograph for each event was compared with SCS hydrograph in HEC-HMS software, and the calibration and correction of SCS coefficients were conducted. The results suggest a correction coefficient of 0.92 for SCSLag, the average ratio of Ia/S is 0.044, which is completely different from 0.2 in SCS. The CN in the study area is 0.41 of CN provided by SCS.
1- Abdullah, R., 2004.Calibration of the Conservation Services (SCS) Method in Peninsular Malaysia Sungai Tasoh Catchment, Negeri Perlis , University of Sains Malaysia. International Conference on Managing Rivers in the 21 st century.
2- Alizadeh, A., 2005. Principles of applied hydrology, Ferdowsi University of Mashhad, 500 p. (InPersian).
3- Anonymous, 1972. National Engineering Handbook, Hydrology, Section 4. United States Department of Agriculture, Soil Conservation Service (Chapters 4–10).
4- Arnold, J. G., Williams, J. R., Srinivasan, R., King, K. W. and Griggs, R. H. 1995. SWAT: Soil Water Assessment Tool. Texas A&M University, Texas Agricultural Experimental Station, Blackland Research Center, Temple.
5- Baltas, E.A., Dervos, N.A. and Mimikou, M.A., 2007. Determination of the SCS initial abstraction ratio in an experimental watershed in Greece. Hydrology and Earth System Sciences Discussions, 11(6), pp.1825-1829.
6- Bo, X.I.A.O., Qing-Hai, W.A.N.G., Jun, F.A.N., Feng-Peng, H.A.N. and Quan-Hou, D.A.I., 2011. Application of the SCS-CN model to runoff estimation in a small watershed with high spatial heterogeneity. Pedosphere, 21(6), pp.738-749.
7- Hawkins, R.H., Jiang, R., Woodward, D.E., Hjelmfelt, A.T., Van Mullem, J.A. and Quan, Q.D., 2002, July. Runoff curve number method: examination of the initial abstraction ratio. In Proceedings of the Second Federal Interagency Hydrologic Modeling Conference, Las Vegas, US Geological Survey, Lakewood, Colorado.
8- Jain, M.K., Mishra, S.K., Suresh Babu, P. and Venugopal, K., 2006. On the Ia–S relation of the SCS-CN method. Hydrology Research, 37(3), pp.261-275.
9- Karrabi, E., Majdzadeh Tabatabai, M. and Ghoreishi Najaf Abadi, S.H., 2015. Effect of Geometric Characteristics of Rivers on Design Discharge in Arid andSemiarid Rivers. Irrigation Sciences and Engineering, 39(1), pp.109-119. (In Persian).
10- Knisel, W.G., 1980. CREAMS: a field scale model for Chemicals, Runoff, and Erosion from Agricultural Management Systems [USA]. United States. Dept. of Agriculture. Conservation research report (USA).
11- Mishra, S.K., Jain, M.K. and Singh, V.P., 2004. Evaluation of the SCS-CN-based model incorporating antecedent moisture. Water resources management, 18(6), pp.567-589.
12- Mishra, S.K., Sahu, R.K., Eldho, T.I. and Jain, M.K., 2006. An improved I a S relation incorporating antecedent moisture in SCS-CN methodology. Water Resources Management, 20(5), pp.643-660.
13- Nadoshani, S.,2005. Hydrological modeling system, Dibagaran Tehran, (InPersian).
14- Neshat, A., Sedghi, H., 2006. To Evaluation the Rate of Run Off Hydrographs of Floods in Bagh Malek Watershed Basin of Khozestan Using SCS Abstraction Parameters and HEC-HMS Model. Agricultural Sciences, 12(4) , pp.787-798. (In Persian) .
15- Sharpley, A.N., 1990. EPIC-erosion/productivity impact calculator: 1, Model Documentation. USDA Techn. Bull. 1759, 235.
16- Shi, Z.H., Chen, L.D., Fang, N.F., Qin, D.F. and Cai, C.F., 2009. Research on the SCS-CN initial abstraction ratio using rainfall-runoff event analysis in the Three Gorges Area, China. Catena, 77(1), pp.1-7.