Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2007
Publication Date: 4/4/2008
Citation: Stone, J.J., Nichols, M.H., Goodrich, D.C., Buono, J. 2008. Long-term runoff database, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research, Vol. 44, W05S05, doi:10.1029/2006WR005733. Interpretive Summary: The American Geophysical Union has a new thrust to make high-quality data available for research by publishing metadata for a data set that will be available on the web in an AGU-approved web site. This is one of a set of thirteen manuscripts describing data from fifty years of research and data collection at the USDA-ARS Walnut Gulch Experimental Watershed (WGEW) in southeast Arizona, USA. This work describes the long-term runoff data set of the WGEW. The runoff data are from 30 watersheds ranging in size from .18 to 14933 ha. This report provides background information on the type of measurement structures, period of record, data quality, and examples of use of the data. Runoff records including hydrographs and summary data are available in several formats via a web interface at http://www.tucson.ars.ag.gov/dap/.
Technical Abstract: Runoff measurement at the semi-arid Walnut Gulch Experimental Watershed began in the middle 1950’s with five critical depth flumes. Since that time, the measurement network has evolved to include measurement structures on 11 large watersheds (227 – 14,933 ha), 8 medium watersheds (35 – 160 ha), and 11 small watersheds (.2 – 5.91 ha). The ephemeral nature of runoff, high flow velocities, and high sediment concentrations in the flow led to the development of the Walnut Gulch supercritical flume used on the large watersheds and the Smith supercritical flume used on the small watersheds. The period of record considered good to excellent ranges from 47 to 26 years. In 1999, the existing analog recording systems were augmented with digital recorders. Runoff occurs at Walnut Gulch primarily as a result of convective thunderstorms during the months of July through September. Runoff volume, peak discharge rate, and flow duration are correlated with drainage area as a result of the limited areal extent of runoff producing rainfall and transmission losses or infiltration of the flood wave into the channel alluvium. Runoff records including hydrographs and summary data are available in several formats via a web interface at http://www.tucson.ars.ag.gov/dap/.