Scientific Investigations Report 2015–5031
The U.S. Geological Survey, in cooperation with the Arkansas Department of Environmental Quality, Southwestern Energy, the Arkansas Natural Resources Commission, and the Arkansas Game and Fish Commission, developed regression equations for estimation of dry season mean monthly flows and harmonic mean flows that are representative of natural streamflow conditions at selected ungaged basins in Arkansas. Observed values of dry season mean monthly flow and harmonic mean flow computed from daily-mean flow data were used with basin characteristics to identify significant explanatory variables for multiple-linear-regression equations to estimate predicted values of dry season mean monthly flow and harmonic mean flow. Five dry season mean monthly flow regression equations and two harmonic mean flow regression equations were developed using dry season mean monthly flows and harmonic mean flows established for 91 and 93 U.S. Geological Survey continuous-record streamflow-gaging stations, respectively. The dry season in Arkansas is defined as the months of July through November for this study. For harmonic mean flow calculations and regression equations, the study area is composed of the Springfield-Salem Plateaus (Arkansas and Missouri), Boston Mountains, Arkansas Valley, Ouachita Mountains (Arkansas and Oklahoma), and West Gulf Coastal Plain (Arkansas) physiographic sections. All continuous-record streamflow-gaging stations used to compute dry season mean monthly flows were located within Arkansas.
Equations for two regions were found to be statistically significant for developing regression equations for estimating harmonic mean flows at ungaged basins; thus, equations are applicable only to streams in those respective regions in Arkansas. Regression equations for dry season mean monthly flows are applicable only to streams located throughout Arkansas. All regression equations are applicable only to unaltered streams where flows were not significantly affected by regulation, diversion, or urbanization. The median number of years used for dry season mean monthly flow calculation was 43, and the median number of years used for harmonic mean flow calculations was 34 for region 1 and 43 for region 2.
First posted March 17, 2015
Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information about viewing, downloading, and printing report files can be found here.
Breaker, B.K., 2015, Dry season mean monthly flow and harmonic mean flow regression equations for selected ungaged basins in Arkansas (ver. 1.1, July 2015): U.S. Geological Survey Scientific Investigations Report 2015–5031, 25 p., http://dx.doi.org/10.3133/sir20155031.
ISSN 2328-0328 (online)
Methods of Analysis for Data from U.S. Geological Survey Continuous-Record Streamflow Gages
Dry Season Mean Monthly Flow and Harmonic Mean Flow Regression Equations
Appendix 1. U.S. Geological Survey Streamflow Gages Used for Regression Analysis for Dry Season Mean Monthly Flow and Harmonic Mean Flow
Appendix 2. Definitions of Basin Characteristics Evaluated as Response Variables for Inclusion in the Regression Analysis
Appendix 3. Dry Season Mean Monthly Flow, Harmonic Mean Flow, and Explanatory Variable Values for Final Regression Equations