GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 257-6
Presentation Time: 9:00 AM-6:30 PM

SNAPSHOTS OF A CHANGING LANDSCAPE:  THE HISTORICAL GEOMORPHOLOGY OF THE LOWER MISSISSIPPI RIVER


BLONIARZ, Andrew and CONSTANTINE, José Antonio, Geosciences, Williams College, Clark Hall, 947 Main Street, Williamstown, MA 01267, ab18@williams.edu

The Mississippi River system has undergone a dramatic transformation since the early days of European exploration throughout the North American heartland in the 16th and 17th centuries.The alteration of the river channel by levees and dams, the near-total deforestation of the river bank, and the dredging of the channel to promote/protect high volume river traffic are just a few examples of how the way the Mississippi operates has been fundamentally changed. Scientific observations of the river and its processes prior to human intervention are scarce and far less comprehensive than what would be made today. This results in a significant lack of trustworthy scientific information about the behavior of the river before the addition of dams, the clearing of debris, and the dredging of the channel. A better understanding of how the Mississippi and its tributaries operated prior to human intervention could provide insight as to how rivers around the world operate/operated before human intervention and how ecosystems and landscapes surrounding these rivers might change as a result of engineering of the rivers. The observations cataloged in this study could influence future research pertaining to the relationship between vegetation and bank stability, changes in land use and sinuosity of the river, and effects of sediment trapping by dams. Using historical descriptions of forms and processes, we describe the conditions of a natural river system just prior to the moment of profound change. These observations seem to parallel conditions in modern river systems at the cusp of extensive land cover classification.