9304104 Slingerland This study will investigate the processes of avulsion, i.e., the permanent diversion of flow away from an existing river channel, and the role of avulsion in the evolution of river floodplains and alluvial sedimentary deposits. The approach will be collaborative, focusing on mathematical modelling experiments, and modern and near-modern river floodplains. The project will attempt to address such questions as the causes of avulsion, the processes by which avulsions initiate and propagate through flood basins, the manner in which floodplains subsequently react to avulsion, and the effects of avulsion on the character of floodplain deposits. Because avulsion is an inevitable consequence of floodplain aggradation, it may play a vital, and heretofore underappreciated, role int he evolution of alluvial sedimentary sequences because it is likely to be a major process of deposition instead of merely a mechanism by which old channels are abandoned and new ones formed. When properly understood, avulsions may require modifications in the way we view the origin and role of meander belts, the relative importance of avulsive vs overbank flooding, and the manners in which floodplain deposits are generated. ***
