Calibration studies typically relate the curve number to the rainfall amount; however, this dependence is neglected in the standard application of the curve-number method. This neglect causes an underestimation of the calculated runoff, which is of concern to engineers. This study quantifies the magnitude of the underestimation of runoff, and identifies the minimum rainfall amounts required for the standard curve-number method to yield runoff estimates with nominal errors less than 10%. These minimum rainfall amounts are shown to be in the range 13-0 cm for curve numbers in the range 40-100. The results also show that a reduced standard initial abstraction ratio below the current standard of 0.2 likely would lead to lower rainfall thresholds for the 10% error.
|Original language||English (US)|
|Journal||Journal of Irrigation and Drainage Engineering|
|State||Published - Jul 1 2021|
ASJC Scopus subject areas
- Civil and Structural Engineering
- Water Science and Technology
- Agricultural and Biological Sciences (miscellaneous)