Submitted to: GIS Applications in Conservation Planning
Publication Type: Book / Chapter
Publication Acceptance Date: September 20, 2012
Publication Date: N/A
Interpretive Summary: The availability of high-resolution topographic information has created the opportunity to improve erosion estimates by more accurately defining the flow paths of runoff water. We modified the Revised Universal Soil Loss Equation, version 2 (RUSLE2) to take advantage of this new source of data. This report describes the approach being taken that enables RUSLE2 to create a detailed map of erosion and deposition within fields and compares predictions to measurements made from 1975 through 2001 at a research watershed located near Treynor, IA. We found that indicate that the approach is feasible and that results can make visible critical areas needing erosion protection. Linking RUSLE2 to a concentrated flow (ephemeral gully) erosion model is still needed and will be the objective of ongoing research.
Technical Abstract: The availability of high-resolution topographic information has created the opportunity for the automatic determination realistic runoff flow paths. To take advantage of this capability, RUSLE2 was modified so that local slope length could be determined based on accumulated runoff, thus creating the opportunity for distributed sheet and rill erosion estimation in a GIS. This report describes the approach being taken to develop a distributed version of RUSLE2, reports on the status of these efforts, and highlights some problems that remain to be resolved. The approach is illustrated through application to the W11 research watershed located near Treynor, IA, that was used as an illustration of how to define proper hillslope flow paths in the RUSLE documentation (Renard et al., 1997). Results indicate that the approach is feasible, but that linking RUSLE2 sheet and rill erosion estimates with a model that accounts for erosion, sediment transport, and deposition in channels will be needed to improve correspondence between predictions and observed field sediment yield.