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://ssdev.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. Limited beta version 4 documentation can be accessed by clicking on the Help button in the user interface. Also, information for user-selected ungaged sites currently cannot be obtained for the Arkansas, Arizona, Georgia, Iowa, Indiana, North Carolina, Oregon, South Carolina, Tennessee, and Washington 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. See the StreamStats home page for a description of the differences in capabilities between version 3 and beta version 4.
Please help us conserve our server system resources by closing the Interactive Map window when you are finished using it. Doing to will help ensure system availablility for all users. Thank you. Please contact the StreamStats by email at firstname.lastname@example.org if you have any questions.
The reports below document the regression equations available in StreamStats for Tennessee, the methods used to develop the equations 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 this report before using StreamStats to obtain estimates of streamflow statistics for ungaged sites.
- Ladd, D.E., and Law, G.S., 2007, Tennessee StreamStats: A Web-Enabled Geographic Information System Application for Automating the Retrieval and Calculation of Streamflow Statistics: U.S. Geological Survey Fact Sheet 2007-3081, 2 p.
- Law, G.S. and Tasker, G.D., 2003, Flood-frequency prediction methods for unregulated streams of Tennessee, 2000: U.S. Geological Survey Scientific Investigations Report 03-4176, 79 p.
- Law, G.S., Tasker, G.D., and Ladd, D.E., 2009, Streamflow-characteristic estimation methods for unregulated streams of Tennessee: U.S. Geological Survey Scientific Investigations Report 2009-5159, 212 p., 1 pl.
General information on the Interactive Map application, as well as specific sources and computation methods for basin characteristics are available here.
NOTE: StreamStats version 3 replaces the low-flow regression equations from Bingham (1986) with newer equations from Law and others (2009). This newer report contains equations for estimating the 7-day, 10-year and 30-day, 5-year low flows, the mean annual flow, the mean summer streamflow (June through August), and flows exceeded 99.5, 99, 98, 95, 90, 80, 70, 60, 50, 40, 30, 20, and 10 percent of the time. The Law and others (2009) report also contained Region-Of-Influence (ROI) methods for estimating the same statistics. The ROI methods have not yet been included in StreamStats.
A stand-alone computer program is available to estimate the flow statistics from the new report using both the conventional regression equations as well as the ROI method. This computer program requires manual entry of the basin characteristics for ungaged sites to obtain estimates of the flow statistics. All of the basin characteristics needed to solve the new equations can be obtained from StreamStats. An advantage of using this program is that it computes the probability of zero flow for the low-flow equations and then outputs zero if the probability is greater than a threshold. StreamStats can be used to obtain the basin characteristics for sites of interest, and the stand-alone program can be run to get estimates of the flow statistics. The new report and the stand-alone program can be downloaded by clicking on the embedded link in the citation above. Users should note that there are some differences in the naming of the basin characteristics between StreamStats and the stand-alone program. The geology factor needed in the stand-alone program is named the streamflow-recession index in StreamStats. Also, the soil fact needed in the stand-alone program is named the percent area underlain by soil permeability of at least 2 in/hr in StreamStats.
StreamStats for Tennessee was developed in cooperation with the Tennessee Department of Transportation and the Tennessee Department of Environment and Conservation.
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