Location: National Soil Erosion Research Lab
Title: Mechanics of Interrill Erosion with Wind-Driven Rain (WDR) Authors
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: June 15, 2010
Publication Date: June 16, 2010
Citation: Erpul, G., Gabriels, D., Norton, L.D., Flanagan, D.C., Huang, C., Visser, S. 2010. Mechanics of Interrill Erosion with Wind-Driven Rain (WDR) [abstract]. United Nations Educational, Scientific and Cultural Organization Chair on Eremology Workshop 'Action of Rain and Wind in Soil Degredation Processes.' June 16, 2010, Ghent, Belgium. 2010 CDROM. Technical Abstract: This article provides an evaluation analysis for the performance of the interrill component of the Water Erosion Prediction Project (WEPP) model for Wind-Driven Rain (WDR) events. The interrill delivery rates (Di) were collected in the wind tunnel rainfall simulator facility of the International Center for Eremology (ICE), Ghent University, Belgium by an experimental setup to work with different raindrop impact velocity vector (RIVV). Synchronized wind and rain simulations with wind velocities of 6, 10 and 14 ms-1 were applied to a test surface placed on both windward (Ww) and leeward (Lw) slopes of 7, 15 and 20%. Based on “Raindrop Detachment and Rain Impacted Flow Transport” (RD-RIFT) mechanics, the measured Di values were compared by using three RIVV responsive parameters which replaced the model term of the effective rainfall intensity (Ie). In the first case, WDR intensity, which vectorally changed with the angle of rain incidence (ARI), was used. The second and third parameters used in the analysis were the resultant kinetic energy flux (KEr) and the normal kinetic energy flux (KErn) of WDR, respectively. The results showed that WDR physics was strongly related to RIVV. There was no significant model enhancement with the described WDR direction only as a function of ARI and with the described resultant velocity without decoupling the distinct roles of two of its components in the interrill erosion processes. The comparative analysis conclusively indicated that vectorally partitioning KErn from KEr for the RD part of RD-RIFT not only explained its individual function in the sub-process but also significantly improved the model’s ability to estimate Di. This finding suggests an area of potential enhancement of the WEPP model components related to interrill detachment for WDR events.