Author(s): Kevin D. Denn; A. N. Thanos Papanicolaou; Christopher G. Wilson
Linked Author(s): Thanos N. Papanicolaou, Kevin Denn
Keywords: Sediment transport; Radionuclide; Flood
Abstract: In June 2008, catastrophic flooding of the Cedar River inundated much of downtown Cedar Rapids, Iowa. As a result, floodwaters deposited a large amount of sediment throughout the city. The sediment origin is of intense scientific and public interest due to the quantity of deposited sediment and the potential presence of persistent organic pollutants attached to the sediment. The primary objective of this study was to determine the temporal and spatial patterns of deposited sediment. Three potential sediment sources were identified: the bed of the Cedar River, the channel banks, and upland areas upstream of Cedar Rapids inundated during the flood. Sediment from the three sources is hypothesized to have been distributed heterogeneously throughout the inundated areas. Samples were gathered from the potential source areas, as well as from terrestrial areas within and adjacent to the flooded region. Radionuclide activities of the samples gathered from the terrestrial areas were compared with samples from the source areas to determine sediment provenance. This comparison will assist in developing a sediment budget for the segment of the Cedar River that flows through downtown Cedar Rapids and identifying the key processes affecting sediment delivery and redistribution that occurred during the flood. Sediment dynamics during floods are poorly described in the existing scientific literature. The goal of this study is to address this lack of knowledge by determining the temporal and spatial patterns of the deposited sediments. The methods established in this study will provide for engineers and researchers the ability to track the transport of sediments in similar events.
Year: 2009