NAME
peakfq - Flood-frequency analysis based on Bulletin 17B
ABSTRACT
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.
METHOD
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.
HISTORY
The program was written in the early 1980's by W. Kirby as
WATSTORE program J407. In the late 1980's, J407 was
included in the program ANNIE (Lumb and others, 1990) for
minicomputers and the PC. The current program completed in
1993 for PC's, UNIX workstations, and minicomputers was
removed from ANNIE, and is a separate program that uses the
AIDE user interface (Kittle and others, 1989), has keyboard
data entry as well as a flat file, and the Watershed Data
Management (WDM) file.
Version 4.1 2002/02/25 - Corrected problems with outputting
the 1.5 and 2.33 -year flood peaks. Revised code to
write summary of statistics to screen for case where
input is from a wdm file and the user has selected YES
for "pause between stations" and NONE for "additional
output".
Version 4.0 2000/12/01 - Revised how skew option was
handled. There were some problems with how the skew
option was handled when multiple data sets were processed
and some of the data sets did not have the skew option
defined; program now warns user and defaults to weighted
skew for those data sets. Systematic frequency curve was
previously drawn over the same probability range as the
Bulletin 17B curve, it is now drawn over the range of the
data values. The program now reports the 1.5 and 2.33
year floods.
Version 3.0 - there was no 3.0 distribution.
Version 2.5 1999/07/30 - No changes in computations.
Revised how skew option was handled. There had been some
problems when multiple wdm data sets were processed and
some of them were missing attributes for the skew option;
the program now warns the user and defaults to weighted
skew. Code groups have been slightly reorganized;
subroutine frqplg has been moved to the libanne awstat
library and duplicated code has been replaced with calls
to dsinf1 (libanne awstat library) and svati4, svatr1,
and svatr2 (libanne waide library).
Version 2.4 1998/03/06 - There are no corrections made to
the actual computations in peakfq; all changes are
cosmetic or made to clarify meaning. User's log files
may need to be modified for cases that specify no pause
and no modifications for ASCII input.
Version 2.3 1997/01/07 - Implemented option to save the
computed statistics in the WATSTORE basin characteristics
'card' format. Correction in computation of generalized
skew caused by incorrect conversion of degree-minute-
second latitude and longitude to decimal degrees (rarely
a problem as latitude and longitude are usually entered
in decimal degrees). Correction problem with incorrectly
printed y-axis scale value in the printer plot option
(roundoff problem found with pc compiler, caused some
scale values smaller than 1.0 to be incorrectly printed,
while the data were correctly scaled.)
Version 2.2 1995/10/27 - Added an option to allow user to
specify that they want to [yes/no] pause between stations
(useful when many stations are being processed). Correct
problem where option flag for including regulated flows
was not always correctly set.
Version 2.0 1994/02 - A new interpolation method for looking
up frequency-curve ordinates (discharges) for given
exceedance probabilities. The new method uses
computations equivalent to straight-line interpolation on
probability paper, whereas the original method was
equivalent to straight-line interpolation on ordinary
arithmetic (rectangular) graph paper. The
interpolations are performed only when the flood record
contains low outliers, zero flows, or flows below the
gage base. The magnitude of the difference between the
two methods can be assessed roughly by plotting the
frequency curves tabulated in Bulletin 17-B for skews of
0 and 1.0 on ordinary arithmetic graph paper and
comparing straight-line interpolation between the plotted
points with a smooth curve drawn through the points.
(For skew of -1.0, the results can be obtained by
interchanging the upper and lower tails of the +1.0-skew
curve.)
The new method is considered to be an improvement over
the original method. However, the original method also
conformed to Bulletin 17-B, and the results of the
original method are not considered significantly
different from those of the new method. In interpreting
or applying the results of any flood-frequency
computation, the statistical-sampling uncertainty
entailed by the length of the flood-data record should be
kept in mind. The magnitude of this uncertainty is
indicated by the confidence limits printed along with the
Bulletin-17B flood magnitude estimates.
Results computed with the February 1994 version (and
later) of the peakfq program are based on the new
interpolation method. Results from earlier versions of
the program are still usable.
DATA REQUIREMENTS
Program input can be a text file in the format described in
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 OPTIONS
Output tables are placed in a text file. Computed
statistics are, optionally, placed on the WDM data set as
attributes for further processing. Frequency plots meeting
USGS publication standards can be displayed on the screen.
Additional plot output options depend on the devices
supported by the GKS library used and may include
PostScript, Computer Graphics Metafile (CGM), Hewlett-
Packard Graphics Language (HP-GL), and assorted printers and
plotters. See the installation instructions (README.TXT)
for details of output devices available with precompiled
distributions of the program.
SYSTEM REQUIREMENTS
PEAKFQ is written in Fortran 77 with the following
extensions: use of include files, INTEGER*2 variables, and
Hollerith constants. Common blocks have mixed character and
noncharacter data. The ANN, WAIDE, AWSTAT, GRAPH, STATS,
AIDE, WDM, ADWDM, and UTIL libraries from LIBANNE are
required to recompile. For more information, see System
Requirements in LIBANNE.
APPLICATIONS
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.
DOCUMENTATION
Kirby, W.H., 1981, Annual flood frequency analysis using
U.S. Water Resources Council guidelines (program J407):
U.S. Geological Survey Open-File Report 79-1336-I,
WATSTORE User's Guide, v. 4, chap. I, sec. C, 56 p.
(Report was updated in 1981.)
RELATED DOCUMENTATION
Flynn, K.M., Hummel, P.R., Lumb, A.M., and Kittle, J.L.,
Jr., 1995, User's manual for ANNIE, version 2, a computer
program for interactive hydrologic data management: U.S.
Geological Survey Water-Resources Investigations Report
95-4085, 211 p.
Interagency Advisory Committee on Water Data, 1982,
Guidelines for determining flood flow frequency: Bulletin
17-B of the Hydrology Subcommittee, Office of Water Data
Coordination, U.S. Geological Survey, Reston, Va., 183
p. [Available from National Technical Information
Service, Springfield VA 22161, (telephone (703) 487-4600)
as report no. PB 86 15 7278.]
Lumb, A.M., Kittle, J.L., Jr., and Flynn, K.M., 1990, Users
manual for ANNIE, a computer program for interactive
hydrologic analyses and data management: U.S. Geological
Survey Water-Resources Investigations Report 89-4080, 236
p. (Documents the 1990 version included in the ANNIE
program.)
REFERENCES
Guimaraes, W.B., and Bohman, L.R., 1991, Techniques for
estimating magnitude and frequency of floods in South
Carolina, 1988: U.S. Geological Survey Water-Resources
Investigations Report 91-4157.
Krug, W.R., Conger, D.H., and Gebert, W.A., 1992, Flood-
frequency characteristics of Wisconsin streams: U.S.
Geological Survey Water-Resources Investigations Report
91-4128.
Landers, M.N., and Wilson, K.V., Jr., 1991, Flood
characteristics of Mississippi streams: U.S. Geological
Survey Water-Resources Investigations Report 91-4037, 82
p.
Lumia, R., 1991, Regionalization of flood discharges for
rural, unregulated streams in New York, excluding Long
Island: U.S. Geological Survey Water-Resources
Investigations Report 90-4197.
Weaver, J.D., and Gamble, C.R., 1993, Flood frequency of
streams in rural basins of Tennessee: U.S. Geological
Survey Water-Resources Investigations Report 92-4165.
Williams-Sether, T., 1992, Techniques for estimating peak-
flow frequency relations for North Dakota: U.S.
Geological Survey Water-Resources Investigations Report
92-4020.
TRAINING
Statistical Approach to Surface-Water Hydrologic Analysis
(SW2011TC), offered annually at the USGS National Training
Center.
CONTACTS
Operation and Distribution:
U.S. Geological Survey
Hydrologic Analysis Software Support Program
437 National Center
Reston, VA 20192
h2osoft@usgs.gov
Official versions of U.S. Geological Survey water-resources
analysis software are available for electronic retrieval via
the World Wide Web (WWW) at:
http://water.usgs.gov/software/
and via anonymous File Transfer Protocol (FTP) from:
water.usgs.gov (path: /pub/software).
The WWW page and anonymous FTP directory from which the
PEAKFQ software can be retrieved are, respectively:
http://water.usgs.gov/software/peakfq.html
--and--
/pub/software/surface_water/peakfq
See
http://water.usgs.gov/software/ordering_documentation.html
for information on ordering printed copies of USGS
publications.
SEE ALSO
annie(1) - Program to list, table, plot data in a WDM file
glsnet(1) - Regional hydrologic regression and network
analysis using generalized least squares
hass-cui(1) - Character-based user interface
iowdm(1) - Program to store time-series data in a WDM file
swstat(1) - Surface-water statistics
wdm(1) - Watershed Data Management system