ESTIMATING AEOLIAN TRANSPORT ALONG THE MISSOURI RIVER AFTER THE 2011 FLOOD

In 2011 the Missouri River experienced the most extensive flooding since the river was dammed in the 1950s. Large sections of the river banks, islands, and floodplains experienced weeks of prolonged inundation, resulting in extensive sand deposition up to 1 km inland from the established channel. Though locally variable, up to several meters of loose sand was deposited and extensive areas of shrub and grassland were completely buried in the inundation zone. The flooding also created a number of new unvegetated islands, an important habitat for endangered species such as the Piping Plover (Charadrius melodus).These newly created sand surfaces are unconsolidated and have very little vegetation to prevent aeolian transport. Strong regional winds have caused substantial sediment fluxes which have modified landscape topography, shifted river morphology, and increased regional dust levels. Using Leatherman style sand traps and erosion pins, we measured transport and accumulation rates at 9 sites of varying vegetation densities along the Garrison Reach, a 110 km section of free flowing Missouri River in North Dakota. Sediment fluxes are applied to transportation model which uses high resolution (~0.4m) remote sensing data of vegetation cover to estimate and map aeolian sediment flux along the river. This project is part of a 3 year study examining the temporal response of aeolian fluxes following a flood as new vegetation growth stabilizes the landscape.