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Results of generalized least-squares (GLS) regression for 136 USGS streamgages in urban areas in Tennessee and parts of Alabama, Georgia, Mississippi, North Carolina, and South Carolina

Metadata Updated: October 2, 2025

This dataset contains results of generalized least-squares (GLS) regression for 136 streamflow gaging stations (streamgages) operated by the U.S. Geological Survey (USGS) on urban streams in Tennessee and parts of Alabama, Georgia, Mississippi, North Carolina, and South Carolina. GLS regression was used to relate drainage area, percentages of the drainage basins of the streamgages in developed land use (the sum of classes 21-24 from the 2011 NLCD; Homer and others, 2015), and the percentages of the streamgage basins in the Piedmont and Ridge and Valley level 3 (L3) ecoregions (U.S. Environmental Protection Agency, 2010) to previously published estimates of streamflows corresponding to the 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, 0.005, and 0.002 annual exceedance probabilities (AEPs; Wagner and Ladd, 2024). From this regression, equations were developed that can be used to predict streamflows corresponding to the eight selected AEPs at ungaged locations on urban streams (percent developed imperviousness greater than 10%; Homer and others, 2015) in the study area. Standard errors of prediction ranged from 35.8 percent for the 0.2 AEP (the 5-year flood) to 55.4 percent for the 0.002 AEP (the 500-year flood). GLS regression was conducted using version 3.0 of USGS weighted regression (WREG) software (Farmer, 2019; Eng and others, 2009); input and output files from WREG are provided. USGS site information, values of the five basin characteristics, at-site estimates of the selected AEPs and their variances (from Wagner and Ladd, 2024), GLS estimates of the selected AEPs and their variances, weighted estimates of the selected AEPs and their variances and associated 95-percent confidence limits (see Appendix 9, "Weighting of Independent Estimates", in England and others, 2019), and the residual, leverage, and influence values from GLS regression are provided in CSV format ("GLSresults.csv"). A table of the final GLS regression equations for each AEP and their associated performance metrics is also provided in CSV format ("RegressionEquations.csv"). The following input files for USGS WREG software are located in the "WREG_input" directory within the "WREG_input.zip" folder: a text file of basin characteristics for all 136 selected streamgages in the study area ("SiteInfo.txt") and a PeakFQ output (.PRT) and export (.EXP) file for each streamgage, located in the "PeakFQ" subdirectory. The following eight WREG output files, located in the "GLS_output" folder within the "GLS_output.zip" directory, are in sub-directories for each of the 8 selected AEPs: "coef.txt," "CoVarMat.txt," "FitandResid.txt," "modelInput.txt," "outputRaw.rda," "PerformanceMetrics.txt," "ResLevInf.txt," and "Weighting.txt."

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date September 14, 2025
Metadata Updated Date October 2, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 14, 2025
Metadata Updated Date October 2, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-660b183ed34e4df16bd58c24
Data Last Modified 2024-10-08T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id ffed19b9-dc67-4cb5-80ed-cbf69a133bfd
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -91.8, 30.0, -75.0, 36.7
Source Datajson Identifier True
Source Hash 08087801ddc4865faa69aa6016702c538d9ea8c99a72cac5e29f54af68fbd47e
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -91.8, 30.0, -91.8, 36.7, -75.0, 36.7, -75.0, 30.0, -91.8, 30.0}

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