Implementation of the U.S. Geological Survey's StreamStats Program in Arkansas -- A Web Application for Streamflow Statistics and Basin Characteristics

Estimates of streamflow statistics are also needed at ungaged sites where no observed flow data are available. Estimates of streamflow statistics for ungaged sites can be made by using regional flow equations developed from data collected at continuous-record streamflow gaging stations that are physiographically similar to the ungaged streams. To determine estimates of flow at ungaged streams, basin characteristics that are used as explanatory variables in the equations are computed using maps or GIS databases and inserted into the regional flow equations.

Over the past 15 years, the USGS Arkansas Water Science Center has conducted three separate studies to develop regional flow equations for Arkansas. Funkhouser and others (2008) have utilized low-flow characteristics from streamflow gaging stations, and unique basin characteristics to develop regional regression equations for the western two-thirds of Arkansas. Funkhouser and Barks (2004) have utilized a regression analysis of dye-tracing measurements to derive an equation to estimate peak velocities. Hodge and Tasker (1995) used regression analysis of flood frequencies and basin characteristics to estimate 50%- to 0.2%-recurrence interval (2- to 500-year magnitude floods) flows at ungaged streams in Arkansas.

To address the needs of entities requiring streamflow information, the USGS has developed a web-based application called StreamStats that serves published streamflow statistics to the public and facilitates the estimation of streamflow statistics for ungaged sites on streams. StreamStats is an integrated web-based GIS application used to make the process of computing streamflow statistics much faster, more accurate, and more consistent than previous methods. StreamStats allows a user to select any point on a stream using a web-based GIS interface, and then determines and displays the area contributing drainage to that point (fig. 1). Once the user confirms the drainage boundary, StreamStats determines the basin characteristics required and which regional equations are available for the location. The basin characteristic values and appropriate regional equations are then used to compute the streamflow statistics and a report showing the computed basin-characteristic values and streamflow statistics is provided.

Implementation of StreamStats in Arkansas will provide planners and managers with an efficient, consistent, and accurate means of obtaining streamflow statistics at gaged stations and estimated streamflow statistics at ungaged stream sites. The URL for the National StreamStats home page is: https://streamstats.usgs.gov