|WORLD METEOROLOGICAL ORGANIZATION||
|Explanation of the criteria for classification and numbering of components||
|Explanation of the dates on the component's description|
ANNUAL FLOOD FREQUENCY ANALYSIS (PEAKFQ)
1. Purpose and objectives
The program PEAKFQ performs flood-frequency analysis of annual peak
flows using Guidelines For Determining Flood Flow Frequency developed by the Interagency Advisory Committee on Water Data (IACWD, 1982).
Flood-frequency analysis using IACWD Bulletin 17B guidelines includes
the calculation of a Pearson Type III frequency curve based on the mean, standard deviation, and skew of the logarithms of the instantaneous annual
peak flows. The computer program PEAKFQ detects and adjusts for low
The program utilizes annual peak flow records in a card-image format, Watershed Data Management (WDM) format, or data input via the keyboard.
Information on the source of the input data, plotting options, historical data and other program-control data are input through a menu-driven user
a. The mean, standard deviation and skew for the systematic record and the final Bulletin 17B frequency curves.
b. A listing of peak flows for selected annual exceedance probabilities ranging from 0.995 to 0.002 both with and without the expected-probability adjustment. Also the 5 and 95 per cent one-sided confidence limits are provided for each selected exceedance probability flow.
c. A ranked listing of annual peak flows and their probability plotting positions.
d. A plot of several flood-frequency curves including the observed, the historically-adjusted, and the
final Bulletin 17B flood-frequency curves.
5. Operational requirements and restrictions
The program PEAKFQ is written in Fortran and has been used on personal computers, workstations, minicomputers and mainframe computers. The
Graphical Kernel System (GKS) is used for plotting the frequency curves. A
GKS library is required to recompile the program on a DOS-based computer and the library is needed to simply run the program on a Unix workstation.
DOS-based computers should have a math coprocessor and 4 megabytes of
6. Form of presentation
Program is distributed on a 3 1/2" floppy diskette or via the
Internet. The users manual, written in English, briefly describes the Bulletin 17B analysis technique and provides guidance on the use of the
7. Operational experience
There have been hundreds of applications of the program throughout the United States.
8. Originator and technical support
U.S. Geological Survey, Office of Surface Water, Reston, Virginia,
From the HOMS National Reference Centre for USA for 3 1/2" floppy or
printed documentation; or electronically on the Internet at: http://water.usgs.gov/software/peakfq.html or http://www.geogr.uni-jena.de/software/
10. Conditions on use
Program and documentation are available free of charge.
Interagency Advisory Committee on Water Data, 1982, Guidelines for determining flood flow frequency: Bulletin 17B of the
Hydrology Subcommittee, Office of Water Data Coordination, U.S. Geological
Kirby, W.H., Lumb, A.M., Flynn, K.M., and Thomas, W.O., Jr., 1994, Users manual for program PEAKFQ, Annual Flood Frequency Analysis Using Bulletin 17B Guidelines: U.S. Geological Survey Water-Resources Investigations Report.
|(First entered: 28 JAN 81||
Last updated: 28 NOV 94)