Scientific Investigations Report 2008–5126
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2008–5126
Prepared in cooperation with the Oregon Department of Transportation
By John Risley, Adam Stonewall, and Tana Haluska
Calculating Flow-Duration and Low-Flow Frequency Statistics at Streamflow-Gaging Stations
Estimating Flow-Duration and Low-Flow-Frequency Statistics at Ungaged Stream Sites
Figure 1. Level III ecoregions of Oregon.
Figure 2. Location of streamflow-gaging stations used in the regression equations.
Figure 3. Residuals of a simple 7Q10 regression equation for the entire study area.
Figure 4. Ten modeling regions used for the regression equations.
Table 1. Description of streamflow-gaging stations used in regression equations for estimating flow-duration and low-flow frequency statistics in Oregon.
Table 2. Selection of streamflow-gaging stations and their number of years of record used in the annual and monthly regression equations for estimating flow-duration and low-flow frequency statistics in Oregon.
Table 3. Monthly consumptive-use adjustments.
Table 4. Annual and monthly flow duration and low-flow frequency statistics for each streamflow-gaging station used in the regression equations.
Table 5. Description of basin characteristics used in regression equations to predict flow-duration and low-flow frequency statistics in Oregon.
Table 6. Basin characteristics for the streamflow-gaging stations used in the regression equations.
Table 7. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 1.
Table 8. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 2.
Table 9. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 3.
Table 10. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 4.
Table 11. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 5.
Table 12. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 6.
Table 13. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 7.
Table 14. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 8.
Table 15. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 9.
Table 16. Regression analysis results for estimating flow-duration and low-flow frequency statistics based on data from Region 10.
Table 17. Maximum and minimum values of basin characteristics used in the regression equations.
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Send questions or comments about this report to the author, John Risley, (503) 251-3279.
For more information about USGS activities in Oregon, visit the USGS Oregon Water Science Center home page.