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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #119282
Title: CURVE NUMBERS, RECENT DEVELOPMENTS

Author
item Hjelmfelt Jr, Allen
item WOODWARD, D
item CONAWAY, G
item PLUMMER, A
item QUAN, Q
item VAN MULLEN, J
item HAWKINS, R
item RIETZ, D

Submitted to: Congress of International Association for Hydraulic Research Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/26/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: The ARS/NRCS Work Group on Curve Numbers is nearing completion of its task of reviewing, revising, and updating the curve number procedures of the NRCS. Revision of chapters concerning Curve Numbers in the NRCS National Engineering Handbook is nearing completion. Modern data mining methods have been applied to the NRCS soils data base to establish the hydrologic soils groups. Data from ARS experimental watersheds have been analyzed to expand the empirical base for the Curve Numbers. This progress is summarized. This research will be of benefit to water resources engineers and planners who will use it in the analysis of the effects of improved practices on watershed responses to rainfall events.

Technical Abstract: A joint work group was formed by the U.S. Department of Agriculture to review the Curve Number procedure in terms of current field measurements. As a result of this work group, much of the National Engineering Handbook (USDA, 1993) has been rewritten to improve consistency and clarity. A fuzzy set theory approach was used to establish a physical basis for classifying soils into Hydrologic Soil Groups. An asymptotic method was developed for determining Curve Numbers from rainfall-runoff data and for determining quality of fit of data to the Curve Number runoff equation.