HR: 1340h
AN: H43A-0362    [Abstracts]
TI: Dynamic Sediment Modeling in Iowa Streams and Rivers: A Case Study at Walnut Creek
AU: * Li, Z
EM: zhongwei-li@uiowa.edu
AF: University of Iowa, 121 TH Department of Geoscience, Iowa City, IA 52242 United States
AU: Zhang, Y
EM: you-kuan-zhang@uiowa.edu
AF: University of Iowa, 121 TH Department of Geoscience, Iowa City, IA 52242 United States
AU: Skopec, M
EM: mskopec@igsb.uiowa.edu
AF: Iowa Geological Survey Bureau, Iowa Department of Natural Resources , Iowa City, IA 52242 United States
AB: Deep channel bed incision and severe channel bank erosion, which have strong effects on the evolution of channel and watershed morphology, are becoming serious problems in natural rivers and streams in Iowa as a result of wide distribution of loess soil material, agricultural activity, river training and human intervention. Consequent high sediment concentration can also cause low water quality and jeopardize aquatic habitat. Dynamic modeling of sediment transport in rivers and streams provides a useful tool for monitoring, controlling and forecasting the morphology change and water quality in channels and watersheds. In order to gain insight into sediment transport process, a dynamic sediment model is built for a 7-mile segment of Walnut Creek in Jasper County, Iowa. This creek was intensively surveyed by Iowa Geological Survey Bureau (IGSB) as part of the Walnut Creek Nonpoint Source Monitoring Project. Besides channel geometry data from the survey, hydraulic and sediment data were collected at two gauges upstream and downstream operated by USGS. A software GSTARS3 developed by USGS is adopted to model both channel bed incision and bank erosion which are typical phenomena in Iowa. The dynamic sediment model is calibrated using channel bathymetry data from recent survey conducted by IGSB. Finally, based on forecasting of flow and sediment discharge time series at the upstream and stage time series at the downstream, a sediment forecasting model is developed to see if the stream can go back to the clarity and morphology of original creek. The study on this small surveyed and controlled creek will benefit our research in other Iowa rivers and streams.
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting