PROGRAM NAME: PEAKFQ - Annual Flood Frequency
Analysis Using Bulletin 17B Guidelines
VERSION/DATE: PKFQWin - Version 5.0 July 2005
OPERATING SYSTEM: Windows
DOCUMENTATION (192 pages)
Bulletin #17B of the Hydrology Committee
Guidelines for Determining Flood Flow Frequency
Revised September 1981
United States Water Resources Council
PEAKFQ performs flood-frequency analysis based on the guidelines delineated in Bulletin 17B, published by the Interagency Advisory Committee on Water Data in 1982. The program is interactive and contains the code from the WATSTORE program J407.
PEAKFQ uses the method of moments to fit the Pearson Type III distribution to the logarithms of annual flood peaks. The skew that is used may be a user-developed generalized skew for a region, from the Bulletin 17B skew map, computed from the data, or weighted between the generalized skew and station skew computed from the data. Adjustments can be made for high and low outliers and historic information. Qualification codes may be used to censor data from the analysis.
Program input can be a text file in the format described the WATSTORE User's Manual, v. 4, chap. I, sec. A; a WDM file; or interactively input with forms displayed on the screen. Input usually comes from a WDM file if regional analysis with the GLSNET program is planned. WDM files are binary, direct-access files that allow for efficient storage and fast retrieval of a large number of data sets. WDM time-series data sets with a yearly time step or table data sets are used by PEAKFQ. The most effective way to add peak-flow data to a WDM file is to use IOWDM, choosing the WATSTORE peak-flow, card-image format option.
Output tables are placed in a text file. Computed statistics are placed on the WDM data set as attributes for further processing. Frequency plots meeting USGS publication standards can be displayed on the screen, converted to a postscript file for output on a laser printer, or redirected to a pen plotter or a metafile.
DOS-based computers having a math coprocessor and 4 mb of memory (supported: IBM-compatible computers with a 386 or greater processor).
There have been hundreds of applications used throughout the United States and the results of these analyses have been published in State or regional flood-frequency reports.