Causes of River Avulsion: Insights from the Late Holocene Avulsion History of the Mississippi River, U.S.A.—Discussion

Our understanding of river avulsions is still in its infancy, especially if we are to rationally predict how, when, and where avulsions will occur. The recent paper by Aslan et al. (2005) sheds new light on the late Holocene evolution of the Lower Mississippi Valley, with particular emphasis on the avulsion that led to the formation of the Atchafalaya River. Although we welcome their contribution and agree with most of their conclusions, we also feel that a key point raised in their paper is somewhat misleading. Aslan et al. (2005) contend that factors other than gradient advantage (notably the presence of buried sand bodies and/or floodplain topography associated with residual channels) are at least as important in determining the occurrence …