USGS Scientific Investigations Report 2010–5185
Regional equations and procedures were developed for estimating seasonal 1-day 10-year, 7-day 10-year, and 30-day 5-year hydrologically based low-flow frequency values for unregulated streams in West Virginia. Regional equations and procedures also were developed for estimating the seasonal U.S. Environmental Protection Agency harmonic-mean flows and the 50-percent flow-duration values. The seasons were defined as winter (January 1–March 31), spring (April 1–June 30), summer (July 1–September 30), and fall (October 1–December 31).
Regional equations were developed using ordinary least squares regression using statistics from 117 U.S. Geological Survey continuous streamgage stations as dependent variables and basin characteristics as independent variables. Equations for three regions in West Virginia—North, South-Central, and Eastern Panhandle Regions—were determined. Drainage area, average annual precipitation, and longitude of the basin centroid are significant independent variables in one or more of the equations. The average standard error of estimates for the equations ranged from 12.6 to 299 percent.
Procedures developed to estimate the selected seasonal streamflow statistics in this study are applicable only to rural, unregulated streams within the boundaries of West Virginia that have independent variables within the limits of the stations used to develop the regional equations: drainage area from 16.3 to 1,516 square miles in the North Region, from 2.78 to 1,619 square miles in the South-Central Region, and from 8.83 to 3,041 square miles in the Eastern Panhandle Region; average annual precipitation from 42.3 to 61.4 inches in the South-Central Region and from 39.8 to 52.9 inches in the Eastern Panhandle Region; and longitude of the basin centroid from 79.618 to 82.023 decimal degrees in the North Region. All estimates of seasonal streamflow statistics are representative of the period from the 1930 to the 2002 climatic year.
First posted December 9, 2010
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Wiley, J.B., and Atkins, J.T., Jr., 2010, Estimation of selected seasonal streamflow statistics representative of 1930-2002 in West Virginia: U.S. Geological Survey Scientific Investigations Report 2010-5185, 20 p.
Description of Study Area
Selected Seasonal Streamflow Statistics
Development of Equations for Estimating Selected Seasonal Streamflow Statistics
Regional Regression Analysis
Procedures for Estimating Selected Seasonal Streamflow Statistics
At a Streamgage
At a Partial-Record Station
At an Ungaged Location
Upstream From a Streamgage Station or Partial-Record Station
Downstream From a Streamgage Station or Partial-Record Station
Between Streamgage Stations and (or) Partial-Record Stations
Hydrologic Conditions Change Linearly Between Streamgage Stations and (or) Partial-Record Stations
Hydrologic Conditions Change Linearly to the Regional Hydrologic Conditions Between Streamgage Stations and (or) Partial-Record Stations
Not on the Same Stream as a Streamgage Station or Partial-Record Station
Example Applications of Procedures for Estimating Selected Seasonal Streamflow Statistics
Limitations of Procedures for Estimating Selected Seasonal Streamflow Statistics