Title:
No-till and Curve Numbers – A Closer Look
No-till and Curve Numbers – A Closer Look
Author(s)
Endale, Dinku M.
Schomberg, Harry S.
Fisher, Dwight S.
Jenkins, Michael B.
Schomberg, Harry S.
Fisher, Dwight S.
Jenkins, Michael B.
Advisor(s)
Editor(s)
Carroll, G. Denise
Collections
Supplementary to
Permanent Link
Abstract
Since its inception in the 1950s, worldwide adoption and use of the Curve Number (CN) methodology for estimating runoff has highlighted some inconsistencies, limitations and problems. Analysis of curve numbers derived from 34 years of rainfall-runoff data, gathered from a 2.7 ha Georgia Piedmont catchment managed under no-till, showed that the average CN (57) that led to mean runoff estimate matching the mean measured runoff was 16 less than the average of the range of CN values (73) given in standard handbook tables for the catchment. The derived median value of the initial abstraction ratio (λ) was 0.04, compared to 0.2, the standard value. Many researchers recommend 0.05 for λ. Use of standard CN coefficients and values for fields managed in no-till, and possibly other conservation tillage systems, would likely lead to overestimation of runoff.
Sponsor
Sponsored by:
Georgia Environmental Protection Division
U.S. Geological Survey, Georgia Water Science Center
U.S. Department of Agriculture, Natural Resources Conservation Service
Georgia Institute of Technology, Georgia Water Resources Institute
The University of Georgia, Water Resources Faculty
Date Issued
2011-04
Extent
Resource Type
Text
Resource Subtype
Proceedings