Is river avulsion style controlled by floodplain morphodynamics? E.A. Hajek, Department of Geosciences, Pennsylvania State University, 511 Deike Building, University Park, Pennsylvania 16803, USA, email@example.com; and D.A. Edmonds, Department of Geological Sciences and Center for Geospatial Data Analysis, Indiana University, 1001 East 10th Street, Bloomington, Indiana 47405, USA. Posted online 10 January 2014, http://dx.doi.org/10.1130/G35045.1.
River relocation, or avulsion, is an important process that distributes sediment, water, and nutrients across landscapes, and can be the cause of unexpected flooding hazards. Two distinct end-member avulsion styles have been observed: one where significant sedimentation occurs on a floodplain as a new river channel is built, and another where a new channel is excavated or eroded into the floodplain. This study explores the degree to which floodplain conditions can be used to predict how new channels form during river avulsion. By comparing generalized floodplain erosion and deposition rates in a given system, it may be possible to predict the likelihood of deposition- or erosional-style river avulsions. This broad rate comparison is shown to explain trends in a series of numerical models and is also consistent with data from ancient river deposits. These results demonstrate that understanding deposition and erosion patterns on floodplains may be useful for anti
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Geological Society of America