Investigation of Interactions Among Near-bank Turbulence, Flow Structure, and Bank Retreat in a Compound Meander Loop

Despite a wealth of research on meandering rivers, few if any studies have examined the structure of turbulence near the outer bank in a field setting or the connections among turbulence, outer bank stresses, and patterns of bank erosion in compound meander bends. Current theory concerning planform migration and meander dynamics is based mainly on findings from experimental settings, modeling approaches, and a limited number of process-based field studies in simple bends. Detailed field studies of compound meander loops, or elongate bends with multiple arcs of curvature, are rare. The aim of this research is to conduct a systematic, process-based field investigation of the interactions between near-bank turbulence, the mean flow field, and bank erosion in a compound meander loop in Central Illinois. This study will answer the following questions: R1 What is the spatial structure of turbulence near the outer bank of a compound meander loop? R1a How does this structure vary spatially and temporally in relation to evolving patterns of the 3-D flow structure as water moves through the bend at various flow stages? R1b How does this structure vary locally in relation to characteristics of the channel bank? R1c How does this structure vary temporally with variations in flow stage? R1d Are coherent turbulent structures detectable near the bank and, how do these structures vary spatially and temporally with position within the loop, bank characteristics, and variations in flow stage? R2 How i