U.S.Geological Survey Water-Resources Investigations Report 94-4002, Nationwide summary of U.S. Geological Surveyregional regression equations for estimating magnitude and frequency of floods for ungaged sites, 1993, by M. E. Jennings,W. O. Thomas, Jr., and H. C. Riggs

In Reply Refer To:                                   January 6, 1995
Mail Stop 415


OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM NO. 95.02

Subject:  U.S.Geological Survey Water-Resources Investigations
          Report 94-4002, Nationwide summary of U.S. Geological Survey
          regional regression equations for estimating magnitude and 
          frequency of floods for ungaged sites, 1993, by M. E. Jennings,
          W. O. Thomas, Jr., and H. C. Riggs

The purpose of this memorandum is to announce the availability of the 
subject report and to make a distribution to Districts and other selected 
offices. In the pocket in the back of the report is a diskette containing 
version 1.1 of the U.S. Geological survey (USGS) National Flood Frequency 
(NFF) program.  This PC program represents a compilation of the current 
USGS regression equations that can be used to estimate the magnitude and 
frequency of flood-peak discharges for rural and urban ungaged sites in 
the 50 States and Puerto Rico.  The report and program should be of 
interest to those individuals involved in flood-frequency analysis.

The NFF program includes over 1,500 regression equations in 210 flood 
regions throughout the country.  Procedures for estimating flood 
hydrographs for selected recurrence-interval peak discharges are also 
available in NFF.  The regression equations and the maps and figures that 
describe the explanatory variables are documented in USGS Water-Resources 
Investigations Report 94-4002.

The USGS plans to update NFF and the documentation every year or two as 
new regression equations are published in various States.  There are also 
plans to redesign the user interface for NFF using a Microsoft Windows 
environment, develop Hypertext help instructions, develop improved 
graphics and provide additional options for hydrograph development.  
Problems with the NFF program, suggestions for improving the program, 
questions about the hydrologic procedures or requests for additional 
copies can be addressed to the Acting Chief, Office of Surface Water.


                                 Ernest F. Hubbard
                                 Acting Chief, Office of Surface Water

Attachment

WRD Distribution: FOL
                  Darrell Carlson, SR, Norcross, Georgia
                  Mike Nolan, WR, Menlo Park, California
                  Ken Wahl, CR, Lakewood, Colorado
                  Terry Lam, NR, Reston, Virginia