U.S. Department of the InteriorU.S. Geological Survey

COMPUTING FLOOD FREQUENCIES USING

USGS PeakFQTransportation Research Board

Washington, DCJanuary 11, 2009

Kate FlynnU. S. Geological SurveyOffice of Surface Water

Reston, Virginia

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PeakFQ

USGS has implemented the Bulletin 17B procedures for flood frequency analysisof streamflow records in the Peak flow FreQuency analysis program. This program has recently been updated and enhanced.

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Features in PeakFQ

New interfacesPKFQWin – Windows (VB)PKFQBat – batch-style, command line

Input formatsWATSTORE text formatWatershed Data Management (.wdm) fileNew Program Specification file (.psf)

New featuresConfidence limits on plotsDocumentation in Windows Help format

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PKFQWin: opening screen

Identify input file by selecting File / Open

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Open PeakFQ File window

Standard Windows openRecognizes predefined file suffixes (pkf, inp, txt, wdm, psf)

Not restricted to predefined suffixes

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PKFQWin: Input file

WATSTORE standard format from NWISWeb

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PKFQWin: Station Specifications tab

Populated with data from the input fileParameters filled from .psf file, I-records in a WATSTORE file, WDM attributes, or defaultsShaded fields are informationalNon-shaded fields can be modifiedMultiple versions of same station are permitted

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PKFQWin: Station Specifications tab

Low outlier threshold

Historic Period

High outlier threshold

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PKFQWin: Output Options tab

Output Options tabis available afterinput file has been openedBy default, output files are named based on the name of the input fileFour graphic plot formatsLine printer plots;o)Click on Run PEAKFQ to start the analysis

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PKFQWin: Results tabResults tab is available after Run PEAKFQ has been selectedText output may be viewed using the system default viewer for text filesGraphs may be viewed

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PKFQWin: View Output FileUses default text file viewer For Notepad

ScrollableFind, select, copy, …Format - font, size, and style

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PKFQWin: View GraphsIf graphical output was selected on the Output tab, graphs will be availableA .bmp file is displayedNo editing

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PKFQWin: .wmf Graph FormatImage can be imported into word, powerpoint, etc.Image can be edited

Bull. 17-B frequencySystematic peaksSystematic frequencyHistorical adjustedConfidence limits

Peakfq 5 run 6/10/2005 13:42NOTE - Preliminary computationUser is responsible forassessment and interpretation.

102

103

104

105

ANNU

AL P

EAK

DISC

HARG

ECU

BIC

FEET

PER

SEC

OND

99.5 98 95 90 80 70 50 30 20 10 5 2 1 0.5 0.2

ANNUAL EXCEEDANCE PROBABILITY, PERCENTStation - 03606500 BIG SANDY / BRUCETON - CHNG 2 SYS PKS + HIST

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PKFQBat

Provides a batch-style interface to PeakFQRun from a command line Run from a scriptSame input and output options as PKFQWinUse .psf file and I records for parameters

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PeakFQ

Current versionRelease dateDocumentationContact

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PeakFQ

PeakFQprogramcan be found at

http://water.usgs.gov/software/PeakFQ/

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Data

USGS peakflow datacan be retrievedin theWATSTOREtext formatat:

nwis.waterdata.usgs.gov/usa/nwis/peak

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Data

Identify station(s)Exact MatchMatch From StartMatch Any Part

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Data

Match from Start

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Data

Select time periodpeakfq formatDisplay in browser or Save to fileSubmit request

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Data

From the File Menu, select Save AsIdentify folderName the file

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Peak Flow Data

peakfq-formated peak flow data can be written to a .wdm file using the IOWDM program found at:

water.usgs.gov/software/iowdm.html

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Example Session . . .