2012 Annual Report 1a.Objectives (from AD-416): 1) Develop enhanced fluvial bank erosion formulations and algorithms for the ARS CONCEPTS channel evolution computer model that incorporate the role of secondary currents and turbulence. . 2)Improve the resistance-to-erosion formulation used to quantify the rate of erosion of cohesive bank materials. . 3)Evaluate the improved algorithms using fluvial bank erosion measurements in the Clear Creek watershed, Iowa. 1b.Approach (from AD-416): Improved understanding of fluvial streambank erosion mechanics will be developed from ongoing studies along two sites on the Clear Creek watershed, Iowa. At the two sites data are continuously collected that comprise both driving and resisting forces, such as bank topography, bank erosion rate, flow field, and boundary material properties. These data will be used to determine a relationship between fluvial bank erosion rate and those factors controlling bank erosion, which will then be incorporated into the CONCEPTS streambank erosion algorithms. The enhanced fluvial streambank erosion algorithm will be utilized in sediment source assessments. 3.Progress Report: The objectives of this agreement were to develop enhanced fluvial bank erosion formulations and algorithms for the CONCEPTS channel evolution computer model that incorporate the role of secondary currents and turbulence, and to improve the resistance-to-erosion formulation used to quantify the rate of erosion of cohesive bank materials. In the first year, we hired a Ph.D. student to work on these objectives. The source code of CONCEPTS was transferred from ARS to the University of Iowa for familiarization of the streambank erosion algorithms. Unfortunately, at the end of the first year the student transferred and no new students were found to work on this agreement. Therefore, no progress was made during the last two years of the agreement.