FLOOD00396

• County: Statewide
• Community: State of Colorado
• Title: Users Manual for Program PEAKFQ, Annual Flood Frequency Analysis Using Bulletin 17B Guidelines
• Date: 1/30/1998
• Prepared By: USGS
• Floodplain - Doc Type: Educational/Technical/Reference Information

CONTENTS

Symbols ....... .................. ........... ..... ........................ .......... ..... ....... i........ ..... ...... ................................................. v
Abstract........... .... .........................,.............................................. i.................................................................... I
Introduction....,..,............ ... ........ ,.."..,..... ,...,.....,......, ..,.....,. ,....,..,!, ". ,......,..... ,....,..... ,... .... ,... .....,.. ..... ....,.. ....,... 1
Peak Streamflow Records.............................,..................,......... .j.................................................................... I
Principles of Computation...................................,..................... .,..........................,......................................... 3
Systematic Record Analysis............................................... .j.................................................................... 3
Outlier and Historic Record Tests........................,...............i....................................................................5
Historic Record Adjustment......................................,.............................................................................. 6
Conditional Probability Adjustment....................................;.......,............................................................ 9
Estimation of Generalized Skew Coefficient.......................,..................................................................10
Computation of Weighted Skew Coefficient.....,.................i................................................................,. II
Expected Probability Adjustment...................................... ..I.............. .................................................... 12
Confidence Limits................................................................:.... .............................................................. 13
Compnter Program PEAKFQ .....................................................i.................................................................. 15
Example: wdm input : .
Opening Screen......... ................................................. ...;.................................................................. 43
Input................ .......... .......... .......... ............ ...... ..............;.................................. ................................ 43
Output.............................................................. ............. ,.................................................................. 47
Modify............. ................................................................................................................................ 49
Start.................. .......... ................................ ...... ...................................... .......................................... 52
Example: ascii input ,
Opening Screen.............................................................;.................................................................. 59
Input....... .......... .................. ............................ ..... ..........:......................................... .................... ..... 59
Output...........................................................................i.................................................................. 61
Start.................................... ............................ .............. +.... ........................................................ ..... 64
Modify.... ................. .......... .......... .................................L.... .......... .......................... .,........................ 65
Program Diagnostics............................................................................................................................... 76
References Cited ...................................... ..'..,............................,.:.................................................................. 77
Appendix A. Description of the AIDE Character-Based User lriterface ....................................................... 78
Appendix B.I. Station Header Records ......................................;..................................................................80
Appendix B.2. Station Option Records..................,....................i.........................,........................................81
Appendix B.3. Peak-Flow Records........................,....................!.................................................................. 83
Appendix C. Data-Set Attributes ............................................,...;..................................................................86

FIGURES

1. General Flow Chart for Bulletin 17B Flood Frequency Computations ....................................................... 4
2. Definition Sketch Showing Time Periods and Discharges Us~d in Historic Record Adjustment............... 7
3. Structure of the PEAKFQ Program ........................................:..................................................................15
4. Example of Output from PEAKFQ for the Fishkill Creek at Beacon, New York...............................:..... 17
5. Example of Output from PEAKFQ for the Floyd River at Iatites, Iowa ................................................... 22
6. Example of Output from PEAKFQ for the Back Creek near Jones Springs, West Virginia..................... 27
7. Example of Output from PEAKFQ for the Orestimba Creek pear Newman, California............ .............. 32
8. Example of Ontput from PEAKFQ for the Sugar Creek at Ciawfordsville, Indiana ................................ 37
A.I. Basic PEAKFQ Screen Layout ...........................................!...................................................................79

TABLES

1. Streamflow-qualification Codes for Peak Streamflow................................................................................ 2
I.a. Correspondence between qualification codes in the peak-flow file and in the peakfq program and
how peakfq handles the associate peaks ..............................'..................................................................... 3

2. Outlier Test KN V alues..........................................................:.....................................................................6
3. Symptoms and Courses of Action for Troubleshooting PEA~Q ............................................................ 59
C.1. Attributes associated with annual peak-flow data sets .......!................................................................... 86
C.2. Sources of attributes associated with peak-flow data sets...'................................................................... 89

PEAKFQ

III

DRAFT -1/30/98