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.
Pennsylvania StreamStats incorporates regression equations for estimating numerous streamflow statistics. Equations are included for estimating the 2-, 5-, 10-, 50-, 100-, and 500-year recurrence interval floods, which have the probability of exceedance in any single year of 50, 20, 10, 2, 1, and 0.2 percent, respectively. Equations also are included for estimating the 7-day, 10-year; 7-day, 2-year; 30-day, 10-year; 30-day, 2-year; and the 90-day, 10-year low flows, the 10-year, 25-year, and 50-year base flows, and the harmonic mean flow, and the mean annual flow. The reports below document the regression equations available in StreamStats for Pennsylvania, the methods used to develop the equations and to measure the basin characteristics used in the equations, references to GIS data layers used in the analysis, 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.
- Roland, M.A., and Stuckey, M.H., 2008, Regression equations for estimating flood flows at selected recurrence intervals for ungaged streams in Pennsylvania: U.S. Geological Survey Scientific Investigations Report 2008-5102, 57 p.
- Stuckey, M.H., 2006, Low-flow, base-flow, and mean-flow regression equations for Pennsylvania streams: U.S. Geological Survey Scientific Investigations Report 2006-5130, 84 p.
General information on the Interactive Map application, as well as specific sources and computation methods for basin characteristics are available here.
In addition to solving the above regression equations, Pennsylvania StreamStats can be used to delineate drainage areas and to provide the basin characteristics that are needed as input for the Baseline Streamflow Estimator (BASE) program, which can estimate daily mean streamflows for 1960-2008 for user-selected sites on ungaged streams. The estimates provided by BASE assume that flows at the selected site are minimally altered by human activities. Additional information on the BASE program, including instructions for downloading, installing, and operating the program are at the following web page:
Note: An adjustment factor is applied to the basin characteristic mean basin slope to more accurately replicate the values used to develop the regression equations. Mean basin slope is used in the regression equation for low-flow region 1. Both the raw (unadjusted) and adjusted basin slope values can be displayed using the BasinChars tool, however, only the adjusted value is displayed on the FlowStats form if the ungaged site of interest is within low-flow region 1.
StreamStats for Pennsylvania was developed in cooperation with the Pennsylvania Department of Protection, the Federal Emergency Management Agency, the Pennsylvania State Association of Township Supervisors, and the Susquehanna River Basin Commission.
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