Estimations of Soil Conservation Service Curve Numbers for Concrete and Asphalt
Publication: Journal of Hydrologic Engineering
Volume 14, Issue 4
Abstract
The purpose of this study was to collect data to estimate curve number (CN) values for concrete and asphalt surfaces and to determine how these values are affected by rainfall intensity and duration, and pavement slope. Two concrete and two asphalt pavements of size at respective slopes of 2.2 and 4.6% and 2.4 and 5% were constructed to conduct field experiments. A water distribution system was specially designed and constructed to simulate rainfall at variable intensities. A total of 64 experiments were conducted. Rainfall intensities ranged from 0.635 to , and rainfall durations ranged from 0.25 to . The CN for concrete was 100 for all conditions. The CN values for asphalt ranged from 97 to 100 with an average of 99. Statistical tests indicated that the average CN values for concrete and asphalt were not equal. As expected, there was a direct relationship between curve number and rainfall intensity and an inverse relationship between curve number; and rainfall duration. The slope did not affect the CN value for concrete but there was an inverse relationship between curve number and slope for asphalt. It is possible that this inverse relationship was due to construction or other defects in the 5% asphalt pavement. The presence of minor cracks in the concrete pavement lowered the CN value to 99 in some cases. The presence of an enhanced “porous” area in the 5% asphalt pavement, less than 1% of the total slab area, reduced the CN values by as much as 10% for relatively low-intensity events. It is likely that the presence of cracks due to construction defects or weathering, construction joints, or other construction defects can significantly reduced the CN value.
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References
Barros, A. P., Knapton, D., Wang, M. C., and Kuo, C. Y. (1999). “Runoff in shallow soils under laboratory conditions.” J. Hydrol. Eng., 4(1), 28–37.
Bosznay, M. (1989). “Generalization of the SCS curve number method.” J. Irrig. Drain. Eng., 115(1), 139–144.
Chow, V. T., Maidment, D. R., and Mays, L. W. (1988). Applied Hydrology, McGraw-Hill, New York.
Garg, V., Chaubey, I., and Haggard, B. E. (2003). “Impact of calibration watershed on runoff model accuracy.” Trans. ASAE, 46(5), 1347–1353.
Haggard, B. E., Moore, P. A., and Brye, K. R. (2005). “Effect of slope on runoff from a small variable slope box-plot.” J. Environ. Hydrol., 13(25), 1–8.
Hawkins, R. H. (1973). “Improved prediction of storm runoff in mountain watersheds.” J. Irrig. and Drain. Div., 99(4), 519–523.
Hawkins, R. H. (1975). “The importance of accurate curve numbers in the estimation of storm runoff.” Water Resour. Bull., 11(5), 887–891.
Hawkins, R. H. (1993). “Asymptotic determination of runoff curve numbers from data.” J. Irrig. Drain. Eng., 119(2), 334–345.
Hawkins, R. H., Woodward, D. E., Hjelmfelt, A. T., Jr., Van Mullem, J. A., and Quan, Q. D. (2002). “Runoff curve number method: Examination of the initial abstraction ratio.” Proc., Federal Interagency Hydrologic Modeling Conf., Las Vegas, July 28–August 1.
Jain, M. K., Mishra, S. K., Babu, P. S., Venugopal, K., and Singh, V. P. (2006). “Enhanced runoff curve number model incorporating storm duration and a nonlinear relation.” J. Hydrol. Eng., 11(6), 631–635.
Mishra, S. K., and Singh, V. P. (1999). “Another look at the SCS-CN method.” J. Hydrol. Eng., 4(3), 257–264.
Nasalas, G. D., Miller, W. W., Gifford, G. F., and Fernandez, G. C. F. (1994). “Effects of soil type, plot condition, and slope on runoff and intersill erosion of two soils in the Lake Tahoe basin.” Water Resour. Bull., 37(6), 319–328.
Pandit, A., and Gopalakrishnan, G. (1996). “Estimation of annual storm runoff coefficients by continuous simulation.” J. Irrig. Drain. Eng., 122(4), 211–220.
Pandit, A., and Gopalakrishnan, G. (1997.) “Estimation of annual pollutant loads under wet weather conditions.” J. Hydrol. Eng., 2(4), 211–218.
Pitt, R. E., and McLean, J. (1986). Toronto area watershed management strategic study—Humber River pilot watershed project, Ontario Ministry of the Environment, Toronto.
Ponce, V. M., and Hawkins, R. H. (1996). “Runoff curve number: Has it reached maturity?” J. Hydrol. Eng., 1(1), 11–19.
Rallison, R. E. (1980). “Origin and evolution of the SCS runoff equation.” Proc., Symp. on Watershed Management, Boise, Idaho, July 21–23, ASCE, Reston, Va., 912–924.
Rawls, W. J., Shalaby, A., and McCuen, R. H. (1981). “Evaluation of methods for determining urban runoff curve numbers.” Trans. ASAE, 24(6), 1562–1566.
Soil Conservation Service (SCS). (1972). SCS national engineering handbook, Sec. 4, U.S. Dept. of Agriculture, Washington, D.C.
Soil Conservation Service (SCS). (1975). “Urban hydrology for small watersheds, SCS.” Technical Release 55, U.S. Dept. of Agriculture, Washington, D.C.
Soil Conservation Service (SCS). (1986). “Urban hydrology for small watersheds, SCS.” Technical Release 55, U.S. Dept. of Agriculture, Washington, D.C.
Soil Conservation Service (SCS). (2007). “Part 630 Hydrology.” National engineering handbook, Chap. 7, U.S. Dept. of Agriculture, Washington, D.C., ⟨http://directives.sc.egov.usda.gov/media/pdf/H_210_630_7.pdf⟩
VerWeire, K. E., Hawkins, R. H., Quan, Q. D., and Scheer, C. C. (2005). “Relationship of hydrologic soils groups to curve numbers: Results of a study.” Proc., ASCE Watershed Management Conf., Williamsburg Va., July 20, ASCE, Reston, Va.
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© 2009 ASCE.
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Received: Feb 7, 2008
Accepted: Dec 3, 2008
Published online: Apr 1, 2009
Published in print: Apr 2009
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