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National Streamflow Statistics Program

National Streamflow Statistics Program

Contact Todd Koenig

 

Version History

National Streamflow Statistics (NSS) database update - 2014-06-12 - This version of the database corrects errors in streamflow estimates encountered in the 2014-05-09 version of the database for the States of Florida, Iowa, Ohio, Pennsylvania, Tennessee, and Utah. For more details, please see the Known Issues link on the NSS software download page.

National Streamflow Statistics (NSS) database update - 2014-05-09 - This version of the database adds new peak urban streamflow equations for Georgia, North Carolina, and South Carolina. Bank-full equations are added for Kentucky, Massachusetts, and Maine. Non-peak streamflow equations are added for Kentucky, New Jersey, and Rhode Island. Standard errors of prediction are updated for Colorado non-peak equations. Kansas non-peak equations are updated to include previously unsupported subtracted terms.

National Streamflow Statistics (NSS) database update - 2013-08-28 - This version of the database adds new peak streamflow equations for Iowa and West Virginia and adds new non-peak streamflow equations for Indiana, Iowa, and Pennsylvania. It corrects peak flow equations in Georgia and North Carolina. It also corrects errors in non-peak equations in Arkansas, Ohio, Oregon, and Vermont and copies Maryland non-peak equations to Delaware.

National Streamflow Statistics (NSS) database update - 2012-11-21 - This version of the database renames peak urban stats in Alabama, adds Standard Error of Prediction to Missouri Urban equations, and adds new peak streamflow equations for California, Florida, Rhode Island, and Virginia. It also adds new urban peak-flow equations for Georgia and low-flow equations for Iowa, Ohio, Virginia, and Washington.

National Streamflow Statistics program (NSS) Version 6.0 - 2012-08-03 - Adds a 64-bit Windows OS compatible installer, brings the flow-type selection to the NSS main screen, adds proper display of Standard errors and prediction intervals for urban scenarios, and improves results display format.

National Streamflow Statistics (NSS) database update - 2012-05-09 - This version of the database prevents negative low-flow results in Oregon, corrects errors in Region 7 peak flow prediction intervals in Illinois, removes outdated ROI equations from North Carolina, renames TAU_x variables in Arkansas, corrects BCF for New York bankfull equations, presents newer ROI routines for Tennessee, and corrects errors in Maryland low-flow equations.

National Streamflow Statistics (NSS) database update - 2011-03-24 - This version of the database adds new urban peak flow equations for Alabama, adds prediction intervals to Arkansas peak flow equations, and adds new low-flow equations for Kentucky. Corrections for low-flow equations from Utah SIR 2008-5230 were entered into this database, and the PK25 covariance matrix was corrected for Puerto Rico. This database should be used with NSS program version 5.1.2 as posted.

National Streamflow Statistics (NSS) database update - 2011-02-04 - This version of the database corrects mislabeled units in Maryland peak flow equations from AHMMD 2010 and corrects mislabeled units in Texas peak flow equations from SIR 2009-5087. This database should be used with NSS program version 5.1.2 as posted.

National Streamflow Statistics (NSS) database update - 2011-01-18 - This version of the database adds new peak-flow equations for Maryland, Oklahoma, and Texas. New urban peak-flow equations were added for Missouri, and new low-flow equations were added for Alaska. This database should be used with NSS program version 5.1.2 as posted.

National Streamflow Statistics (NSS) database update - 2010-11-15 - This version of the database adds new low-flow or flow-duration equations for Oregon, Arkansas, Tennessee, New York, Hawaii, Washington, and Ohio. Arkansas region-of-influence (ROI) equationswere removed. Errors were corrected in non-peak-flow equations for Maryland and peak-flow equations for Hawaii, Maine and Nevada. Prediction interval calculations were added for New Hampshire. This database should be used with NSS program version 5.1.2 as posted.

National Streamflow Statistics program (NSS) Version 5.1.2 - 2010-11-15 - Adds the ability to filter equations by one of three types: "Peak", "Probability" (of zero flow), and "Other" (non-peak). Please go to File...Options within the program to select a flow type before using the program. Also adds the ability to display peak flow statistics with traditional recurrence interval labels or newer percent chance exceedance labels (e.g. "PK100" vs. "1% flood").

National Streamflow Statistics (NSS) database update - 2010-07-26 - This version of the database corrects an error in Region 3 equations for Wisconsin. Peak-flow and low-flow equations in New Hampshire are updated with prediction interval computation. New peak equations for Hawaii are updated to coincide with recent revisions. This database should be used with NSS program version 5.1 as posted. There are no changes to the program version 5.1.

National Streamflow Statistics (NSS) database update - 2010-06-21 - This version of the database adds new peak-flow equations for Colorado, Georgia, Hawaii, Minnesota, North Carolina, New Jersey, Oklahoma, and South Carolina. New duration equations are added for Connecticut and Oklahoma. Equation errors are corrected for mean flow equations in Ohio. This database should be used with NSS program version 5.1 as posted.

National Streamflow Statistics Program (NSS) Version 5.1 - 2010-06-21 - Added the ability to solve a wider range of regression equations and to weight streamflow estimates by variance. Added new functionality that will eventually result in being able to describe streamflows in terms of annual exceedance probabilities or recurrence intervals. Identified and corrected a problem with prediction interval computations.

National Streamflow Statistics (NSS) database update - 2009-07-20 - This version of the database adds peak flow equations from New Hampshire report SIR 2008-5206. It also includes missing PK500 estimates for Alabama and Hawaii that were mistakenly deleted in previous versions and also includes minor modifications to equations from Kentucky report WRIR 91-4097. This database should be used with NSS program version 4.0b as posted. There are no changes to the NSS program version 4.0b.

National Streamflow Statistics (NSS) database update - 2009-04-08 - This version of the database adds peak-flow equations for West Virginia and Oklahoma and low-flow equations for Kentucky, Utah, and West Virginia. This database should be used with NSS program version 4.0b as posted. There are no changes to the NSS program version 4.0b.

National Streamflow Statistics (NSS) database update - 2009-02-27 - There are no changes to the NSS program version 4.0b. This version of the database adds peak-flow equations for New Mexico and corrects some error statistics in Florida. This database should be used with NSS program version 4.0b as posted.

National Streamflow Statistics (NSS) database update - 2009-01-27 - There are no changes to the NSS program version 4.0b. This version of the database adds peak-flow equations for Arkansas, South Carolina, and Florida. It also adds urban peak equations for New York and updates urban equations for North Carolina's Blue Ridge and Piedmont regions. This database should be used with NSS program version 4.0b as posted.

National Streamflow Statistics Program (NSS) Version 4.0b - 2008/12/08 - Added the abilities to (1) handle regression equations that have a multiple explanatory variables in the exponent term; (2) incorporate logistic regression equations that are found in some low-flow reports (ie the chance of a stream having zero flow); and (3) enable computing of area-weighted prediction intervals for sites with drainage area in more than one hydrologic region. In addition there was some cleanup in the way regression equations were presented in the output report.

New peak-flow equations have been added for Alabama, Arizona, Colorado, Florida, Louisiana, New Mexico, New York, Pennsylvania, South Carolina, and Utah, including completion of Utah Region_4. New low-flow equations have been added for Florida, Hawaii, Idaho, Montana, and Tennessee. Minor corrections were made to existing equations for Alabama, Delaware, Idaho, Illinois, Indiana, Texas, and Utah, including adding the ability to do prediction intervals for Indiana flood frequency estimates.

National Streamflow Statistics program (NSS) Version 4.0 - 2006/12/01 - Added the abilities to (1) solve regression equations for all types of streamflow statistics, not just flood-frequency statistics, (2) use region-of-influence regression for states where it is implemented, (3) compute 90-percent prediction intervals for estimates where methods for computing them are documented in reports.

National Flood Frequency program (NFF) Version 3.2 - 2004/12/14 - Updated the database to NFFv3.2_2004-12-14.mdb. Added new peak-flow equations for Connecticut and Kentucky. Corrected an error in the units displayed for conveyance in the Houston urban equations from in/hr to cubic feet per second. Corrected an error in the Wisconsin Area 1 equation for the 5-year recurrence interval.

National Streamflow Statistics program (NSS) Version 4.0 2006/12/01 - Added the abilities to (1) solve regression equations for all types of streamflow statistics, not just flood-frequency statistics, (2) use region-of-influence regression for states where it is implemented, (3) compute 90-percent prediction intervals for estimates where methods for computing them are documented in reports.

National Flood Frequency program (NFF) Version 3.2 - 2004/12/14 - Updated the database to NFFv3.2_2004-12-14.mdb. Added new peak-flow equations for Connecticut and Kentucky. Corrected an error in the units displayed for conveyance in the Houston urban equations from in/hr to cubic feet per second. Corrected an error in the Wisconsin Area 1 equation for the 5-year recurrence interval.

NFF Version 3.2 - 2004/09/29 - Updated the database to NFFv3.2_2004-09-29.mdb. This database contains new peak-flow equations for Alaska, Idaho, Ohio, Tennessee, Vermont, Wisconsin, and Wyoming. Along with the new database comes the ability to display 90-percent prediction intervals with the estimates for some of the updated States.

NFF Version 3.2 2003/04/30 - Fixed a bug in the weighting routine that occurred when equivalent years of record were missing for the regression estimates, and a bug that occurred when the drainage area for an ungaged site was in more than one region and the regions had different sets of return intervals.

NFF Version 3.1.1 - 2003/03/28 - Fixed a bug in the weighting routine that was introduced in the version 3.1 update.

NFF Version 3.1 - 2003/02/27 - Fixed a problem with solving the national urban equations that occurred when one or more of the local rural equations were missing for the region of interest. If a rural equation, such as the 5-year flow, was missing NFF would use the flow estimate for the next available recurrence interval, such as the 10-year flow, to estimate the urban flow for the missing recurrence interval. All estimates for higher recurrence intervals would also be incorrect.

NFF Version 3.0 - 2002/10/15 - Major change in converting user interface from Microsoft DOS to Microsoft Windows and converting data base from a binary file to Microsoft Access (Note: Use of trade or product names is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey). Updates or corrections to equations for

  • Alabama
  • Alaska
  • American Samoa
  • Arizona
  • Arkansas
  • Colorado
  • Delaware
  • Georgia - rural and urban
  • Hawaii
  • Idaho
  • Iowa
  • Kansas
  • Kentucky - Jefferson County urban
  • Louisiana
  • Maine
  • Maryland
  • Minnesota
  • Missouri
  • Nebraska
  • Nevada
  • New Mexico
  • North Carolina - rural and urban
  • Oklahoma
  • Pennsylvania
  • Puerto Rico
  • South Carolina - rural and urban
  • South Dakota
  • Texas - rural
  • Utah
  • Virginia
  • Washington
  • West Virginia

NFF Version 2.0 - 1996/09/15 - A non-USGS release that added conversions between English and metric units.

NFF Version 1.4 - 1996/09/30 - NFF data base updated to amend incorrect values for:

NFF Version 1.3 - 1996/02/14 - Corrected labeling of flood-frequency recurrence intervals for North Dakota. The equations developed for North Dakota are for the 2-, 10-, 15-, 25-, 50-, 100-, and 500-year recurrence intervals rather than the standard 2-, 5-, 10-, 25-, 50-, 100-, and 500-year intervals.

NFF Version 1.2 - 1995/06/02 - NFF data base updated to amend incorrect exponents in West Virginia's Region 6 equations for the 2-year and 10-year recurrence interval.

NFF Version 1.1 - 1994/11/21 - Initial release.