Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/11/2008
Publication Date: 4/3/2008
Citation: Mckinnon, R.J., Dowd, J.F., Endale, D.M., Franklin, D.H. 2008. Artificial rainfall simulation of pressure wave generated runoff [abstract]. The 16th Annual David S. Snipes/Clemson Hyrogeology Symposium, April 3-4, 2008, Clemson, South Carolina.
Technical Abstract: Previous gutter experiments, monitoring nearly a year of natural rainfall and subsequent runoff in a study plot situated on a hill slope at the USDA-ARS J, Phil Campbell Sr. Natural Resource Conservation Center in Watkinsville, Georgia, suggest a close relationship between rainfall intensity and shallow subsurface runoff. To further evaluate the rainfall/runoff relationship, a pair of artificial rainfall simulations was conducted within the same Piedmont region study plot. Environmental and climatic conditions, such as timing, intensity, and volume of rainfall, were manipulated to observe the runoff response with the gutter collection system. During rainfall simulation, gutter flow abruptly started and stopped with rainfall. This was similar to the gutter response to natural rainfall. Abrupt cessation of gutter flow suggests that saturated subsurface flow was not a mechanism. Tensiometers installed in the gutter soil face indicate a threshold gutter response, but were not well-correlated with runoff. No overland flow was observed until very late in the experiment. Deuterium analysis confirmed that the runoff was primarily pre-event soil water. Further research regarding the observed phenomena may lead to a better understanding of storm flow pathways and chemical/pollutant transport within a catchment.