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Minnesota Water Science Center

Methods Used to Compute Low-Flow Frequency Characteristics for Continuous-Record Streamflow Stations in Minnesota, 2006

U.S. Geological Survey, Open-File Report 2007-1033

By Thomas A. Winterstein, Allan D. Arntson, and Gregory B. Mitton

In cooperation with the Minnesota Pollution Control Agency

ONLINE ONLY


This report is available below, in multiple sections, as a 762-page PDF for viewing and printing.


Abstract

The 1-, 7-, and 30-day low-flow series were determined for 120 continuous-record streamflow stations in Minnesota having at least 20 years of continuous record. The 2-, 5-, 10-, 50-, and 100-year statistics were determined for each series by fitting a log Pearson type III distribution to the data. The methods used to determine the low-flow statistics and to construct the plots of the low-flow frequency curves are described. The low-flow series and the low-flow statistics are presented in tables and graphs.

Contents

Abstract


Introduction


Methods Used to Compute Low-Flow Statistics


References Cited


Appendix 1. Log-normal plots of low-flow frequency statistics


Appendix 2. Log Pearson type III plots of low-frequency statistics


Appendix 3. Output from the computer program SWSTAT

Figures

  1. Map showing continuous-record streamflow stations used in low-flow analysis in Minnesota, 2006.


  2. Example of output from the computer program SWSTAT.


3–6. Graphs showing:


3. Low-flow frequency curves plotted along a normal probability axis showing effects of skews on the shape of the curve.

4. Low-flow frequency curve with skew equal to zero plotted along a normal probability axis.

5. Low-flow frequency curves plotted along a Pearson type III probability axis showing effects of skew on the position of the 0.50 probability line.

6. One-day low-flow frequency curves for continuous-record streamflow station 05279000, South Fork Crow River near Mayer, Minnesota, showing the effects of zero values on the shape of the frequency curve.

 

Tables

  1. Continuous-record streamflow stations used in the analysis.

Availability

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small image of front cover


Cover 1 through page 17 - 22 pages (679 KB) (8.5" by 11" paper)


Appendix 1 - 120 pages (1.71 MB) (8.5" by 11" paper)


Appendix 2 - 120 pages (1.39 MB) (8.5" by 11" paper)


Appendix 3 - 505 pages (1.84 MB) (8.5" by 11" paper)


Cover 4 (20.7 KB) (8.5" by 11" paper)


Suggested Citation:

Winterstein, T.A., Arntson, A.D., and Mitton, G.B., 2007, Methods Used to Compute Low-Flow Frequency Characteristics for Continuous-Record Streamflow Stations in Minnesota, 2006: U.S. Geological Survey Open-File Report 2007-1033, 762 p.



For more information about USGS activities in Minnesota, visit the USGS Minnesota Water Science Center home page.


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