ARS | Publication request: How Soil Roughness Affects Runoff and Sediment Production?

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 15, 2006
Publication Date: September 26, 2006
Citation: Huang, C., Darboux, F. 2006. How Soil Roughness Affects Runoff and Sediment Production? [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. November 12-16,2006, Indianapolis, IN. 2006 CDROM.

Technical Abstract: Effects of soil surface roughness on runoff and sediment production have not been clearly quantified, mostly due to the lack of a logical separation between geometric (i.e., surface microtopography) and process (i.e., runoff generation, soil detachment by raindrop and runoff) scales. In this research, we separated soil roughness, based on its functional form, into depressions and mounds due to their converging and diverging nature and studied their effects under laboratory rainfall simulation. Our results showed that the only significant roughness effect is the delayed runoff initiation from surface depressions. At steady state, surface with depressions produced slightly greater runoff, possibly due to more water on the surface and sealing of the depressions. At steady state runoff, there is no difference in sediment production between surfaces with depressions or mounds and those without. Current erosion prediction models, i.e., RUSLE and WEPP predict a reduced soil erosion with an increased soil roughness. This prediction is only partially correct when rainfall is not sufficient enough to produce full runoff.