Beta version 4 has arrived!
Beta version 4 is now available for most states on a trial basis, and version 3 remains available. Beta version 4 provides a single user interface (at http://streamstatsags.cr.usgs.gov/streamstats/) for all states that are implemented, rather than separate applications for each state, as in versions 2 and 3, and the user interface is more user friendly than previous versions. Information for user-selected ungaged sites currently cannot be obtained using beta version 4 for the States of Arkansas, Arizona, Georgia, Iowa, Indiana, Maryland, North Carolina, Oregon, South Carolina, and Tennessee because of unique functionality for those states that is not yet implemented. Users are encouraged to provide comments and report bugs by use of the Help button on the interface, which also provides access to limited beta version 4 documentation. See below for additional information about versions both 3 and 4.
Please contact the StreamStats by email at email@example.com if you have any questions.
Oklahoma StreamStats incorporates statewide regression equations for estimating instantaneous peak flows with annual exceedance probabilities of 50, 20, 10, 4, 2, 1, and 0.2 percent. These peak flows have recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years, respectively. Oklahoma StreamStats also incorporates regional regression equations for estimating the mean annual flow and annual and monthly flow exceeded 20, 50, 80, 90, and 95 percent of the time. The reports below document the regression equations, the methods used to develop them and to measure the basin characteristics used in the equations, and the errors associated with the estimates obtained from the equations. Users should familiarize themselves with these reports before using StreamStats to obtain estimates of flows for ungaged sites in drainage basins.
- Lewis, J.M., 2010, Methods for Estimating the Magnitude and Frequency of Peak Streamflows for Unregulated Streams in Oklahoma: U.S. Geological Survey Scientific Investigations Report 2010-5137, 42 p.
- Esralew, R.A., Smith, S.J., 2009, Methods for estimating flow-duration and annual mean-flow statistics for ungaged streams in Oklahoma: U.S. Geological Survey Scientific Investigations Report 2009-5267, 131 p.
Between approximately May 19, 2015 and November 1, 2015, Oklahoma’s StreamStats application was producing peakflow estimates based on an incorrect precipitation grid. Differences in the precipitation amounts varied with location and basin size, but the incorrect precipitation values averaged approximately 6 percent lower than the correct values. While these incorrect precipitation values would have resulted in peakflow estimates with a low bias, the error would be within the model error of the peakflow regression equations.
General information on the Interactive Map application, as well as specific sources and computation methods for basin characteristics are available here.
Contact Us if you experience any problems with this application.