Theoretical Justification of SCS Method for Runoff Estimation
Publication: Journal of Irrigation and Drainage Engineering
Volume 124, Issue 6
Abstract
The Soil Conservation Service (SCS) method is widely used to estimate runoff from small- to medium-sized watersheds. The most critical assumption of the SCS method is that the ratio of the actual retention to the potential retention is the same as the ratio of actual runoff to potential runoff, but this assumption has not been theoretically nor empirically justified. This paper shows that the exact relationship between rainfall and runoff in the SCS method can be derived theoretically if two simple but reasonable assumptions are made: (1) The spatial variation of infiltration capacity has an exponential distribution; and (2) the temporal variation of rainfall rate also follows an exponential distribution. A theoretical basis for the SCS method allows an independent validation of the method by testing how rainfall intensity and infiltration capacity actually vary in time and space, respectively.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Cook, H. L.(1946). “The infiltration approach to the calculation of surface runoff.”Eos Trans. Am. Geophysical Union, 27, 726–747.
2.
Flanagan, D. C., Foster, G. R., and Moldenhauer, W. C.(1988). “Storm pattern effect on infiltration, runoff, and erosion.”Trans. ASAE, 31, 414–420.
3.
Green, G. H., and Ampt, G. A.(1911). “Studies on soil physics, Part I. The flow of air and water through soils.”J. Agric. Sci., 4, 1–24.
4.
Hawkins, R. H. (1982). “Interpretation of source-area variability in rainfall-runoff relationships.”Rainfall-runoff relationships, V. P. Singh, ed., Water Resources Publications, Fort Collins, Colo., 303–324.
5.
Hawkins, R. H., and Cundy, T. W.(1987). “Steady-state analysis of infiltration and overland flow for spatially-varied hillslopes.”Water Resour. Bull., 23, 251–256.
6.
Hershenhorn, J., and Woolhiser, D. A.(1987). “Disaggregation of daily rainfall.”J. Hydro., Amsterdam, The Netherlands, 95, 299–322.
7.
Hjelmfelt, A. T.(1991). “Investigation of curve number procedure.”J. Hydr. Engrg., ASCE, 117(6), 725–737.
8.
Horton, R. E.(1933). “The role of infiltration in the hydrologic cycle.”Trans. Am. Geophysical Union, 14, 446–460.
9.
Hutchinson, M. F.(1995). “Stochastic space-time weather models from ground-based data.”Agric. and Forest Meteorol., 73, 237–264.
10.
Littleboy, M., Silburn, D. M., Freebairn, D. M., Woodruff, D. R., Hammer, G. L., and Leslie, J. K.(1992). “Impact of soil erosion on production in cropping land systems. I. Development and validation of a simulation model.”Aust. J. Soil Res., Melbourne, Australia, 30, 757–774.
11.
Loague, K., and Gander, G. A.(1990). “R-5 revisited 1. Spatial variability of infiltration on a small rangeland catchment.”Water Resour. Res., 26, 957–971.
12.
Maidment, D. R., ed. (1993). Handbook of hydrology. McGraw-Hill Inc., New York.
13.
Moldenhauer, W. C., Burrows, W. C., and Swartzendruber, D.(1960). “Influence of rainfall storm characteristics on infiltration measurements.”7th Int. Congr. Soil Sci., Int. Soc. of Soil Sci., 1, 426–432.
14.
Murai, H., and Iwasaki, Y. (1975). “Studies on function of water and soil conservation based on forest land (I)—Influence of difference in forest condition upon water run-off, infiltration and erosion.”Bulletin No. 274, Gov. Forest Exp. Sta., Tokyo, Japan, 23–84.
15.
Nielsen, D. R., Biggar, J. W., and Erb, K. T.(1973). “Spatial variability of field-measured soil-water properties.”Hilgardia, 42, 215–259.
16.
Philip, J. R.(1957). “The theory of infiltration: 1. The infiltration equation and its solution.”Soil Sci., 83, 345–357.
17.
Pilgrim, D. H., and Cordery, I. (1993). “Flood runoff.”Handbook of hydrology, D. R. Maidment, ed., Chap. 9, McGraw-Hill Inc., New York, 41.
18.
Ponce, V. M. (1989). Engineering hydrology: Principles and practices. Prentice-Hall, Inc., Englewood Cliffs, N.J.
19.
Rallison, R. E. (1980). “Origin and evolution of the SCS runoff equation.”Proc., Symp. on Watershed Mgmt., ASCE, New York, 912– 924.
20.
Richardson, C. W. (1981). “Stochastic simulation of daily precipitation, temperature, and solar radiation.”Water Resour. Res., 17, 182–190. SCS National Engineering Handbook . (1985). Sec. 4, Hydrology, U.S. Dept. of Agric. Soil Conservation Service, Washington, D.C.
21.
Sharma, M. L., Gander, G. A., and Hunt, C. C.(1980). “Spatial variability of infiltration in a watershed.”J. Hydro., Amsterdam, The Netherlands, 45, 101–122.
22.
Singh, V. P. (1992). Elementary hydrology. Prentice-Hall, Inc., Englewood Cliffs, N.J.
23.
Steenhuis, T. S., Winchell, M., Rossing, J., Zollweg, J. A., and Walter, M. F.(1995). “SCS runoff equation revisited for variable-source runoff areas.”J. Irrig. and Drain. Engrg., ASCE, 121(3), 234–238.
24.
Stidd, C. K.(1973). “Estimating the precipitation climate.”Water Resour. Res., 9, 1235–1241.
25.
Todorovic, P., and Woolhiser, D. A.(1975). “A stochastic model of n-day precipitation.”J. Appl. Meteorology, 14, 17–24.
26.
Williams, J. R., Nicks, A. D., and Arnold, J. G.(1985). “Simulation for water resources in rural basins.”J. Hydr. Engrg., ASCE, 111, 970–986.
27.
Woolhiser, D. A. (1992). Modeling daily precipitation—Progress and problems. Statistics in the environmental & earth sciences, A. T. Walden and P. Guttorp, eds., Edward Arnold, Ltd., London, 71–89.
28.
USDA Soil Conservation Service. (1986). “Urban hydrology for small watersheds.”Tech. Release No. 55 (TR-55), Washington, D.C.
29.
Yu, B., Rose, C. W., Coughlan, K. J., and Fentie, B.(1997). “Plot-scale rainfall-runoff characteristics and modeling at six sites in Australia and South-East Asia.”Trans. ASAE, 40, 1295–1303.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 124 • Issue 6 • November 1998
Pages: 306 - 310
Copyright
Copyright © 1998 American Society of Civil Engineers.
History
Published online: Nov 1, 1998
Published in print: Nov 1998
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.