Walker Branch Watershed Stream Discharge and Annual Runoff

The long-term Walker Branch Hydrology Monitoring project is intended to document changes in the water balance (precipitation inputs, stream discharge outputs) for the Walker Branch Watershed over time.

This data set contains annual runoff records (annual discharge divided by subcatchment area) beginning 1969, daily stream discharge records beginning 1969, and 15-minute stream discharge records beginning 1996.

Spatial Extent:
West Fork subcatchment = 38.4 ha
East Fork subcatchment = 59.1 ha
Entire watershed = 97.5 ha

GIS data set information - See Walker Branch Watershed Project website: http://walkerbranch.ornl.gov/

Parameters measured and methods:

The streams draining each of the two subcatchments of Walker Branch (East and West Forks) are monitored for discharge with 120-degree V-notch weirs. Discharge up to 1.18 m3/s can be measured with the V-notch weirs, and higher discharges up to 1.86 m3/s are monitored with a sharp-crested, rectangular cross section above the V-notch weir. The stream stage heights were monitored with a Fisher and Porter model 1542 punched-tape water-level recorder at 5-minute (until 1989) or 15-minute intervals with a resolution of 0.3 mm. Beginning in 1999 stream stage heights were monitored electronically with a Stevens Type A/F encoder at 15-min intervals. The conversion of stage height to discharge for stage heights <2.5 feet is calculated by means of a regression equation as follows:

Discharge (L/s) = 125.37 x (stage height in feet)**2.449

The measurement uncertainty is +/- 5% at low flows (<0.004 m3/s) and +/- 0.5% at flows > 0.125 m3/s. Flows seldom exceed 0.7 m3/s.

Publications:

Curlin, J. W., and D. J. Nelson. 1968. Walker Branch Watershed project: Objectives, facilities, and ecological characteristics. ORNL/TM-2271. Oak Ridge National Laboratory, Oak Ridge, TN.

Luxmoore, R. J. 1983. Water budget of an eastern deciduous forest stand. Soil Science Society of America Journal 47:785-791.

Luxmoore, R. J., and D. D. Huff. 1989. Water. Chapter 5, pages 164-196. In : D. W. Johnson and R. I. Van Hook, eds., Analysis of Biogeochemical Cycling Processes in Walker Branch Watershed. Springer-Verlag, New York.

Research on Walker Branch Watershed is funded by the U.S. Department of Energy, Office of Biological and Environmental Research.