|Wells, Robert - Rob|
Submitted to: Laboratory Publication
Publication Type: Government Publication
Publication Acceptance Date: 10/2/2007
Publication Date: 10/3/2007
Citation: Wells, R.R., Simon, A., Alonso, C.V. 2007. Goodwin Creek Experimental Watershed: Bendway Model Data Report. USDA-ARS National Sedimentation Laboratory Research Report. No. 57. 102 pp. Interpretive Summary: Many streams in agricultural watersheds are characterized by unstable channel boundaries. Erosion in these unstable channels destroys valuable agricultural land, and also degrades the stream habitat for fish and other aquatic organisms. Determining the velocity and area of the flows in a stream that are responsible for maintaining the channel and the aquatic habitat are essential information for use by river engineers to restore impacted channels to a more natural state. Current technologies to predict channel responses are hindered by an incomplete understanding of the processes controlling erosion of streambanks, channel meandering and migration, erosion of cohesive sediment, and the links between bed and bank processes. An eroding bendway is being intensely studied to improve knowledge of these processes. Data collected at this actively eroding streambank includes cross-section surveys, water levels, bank pore-water pressures, and bank-material strength. These data have been used as a prototype for the evaluation of Total Maximum Daily Loads (TMDLs) for clean sediment in streams and rivers. Watershed-scale models employing best management practices have been developed using the GCEW database and are a valuable component for guiding management strategies to rectify impaired streams of the U.S. The Goodwin Creek bendway modeling project was initiated in cooperation with the National Center for Computational Hydroscience and Engineering (NCCHE), located on the University of Mississippi campus at Oxford, MS, in 2004 to simulate flow along the bendway with 2-dimensional and 3-dimensional free-surface flow models using recent cross-sectional geometry and data from an extreme flow event that occurred April 6, 2005. The goal of the project is to better understand the dynamic nature of the flow in the bendway and gain logistical information concerning points/zones of special interest for more detailed study. This report focuses on the data compiled for the model simulations.
Technical Abstract: The Goodwin Creek Experimental Watershed is a 21.3 km2 watershed near Batesville, Mississippi. The watershed is organized and instrumented for conducting extensive research on upstream erosion, stream erosion and sedimentation, and watershed hydrology. Data collection is directed towards providing information needed to test physical concepts and mathematical models of watershed runoff, streamflow, and sediment transport processes. The Goodwin Creek bendway modeling project was initiated in cooperation with the National Center for Computational Hydroscience and Engineering (NCCHE) at the University of Mississippi in 2004 to simulate the flow along the bendway with 2-dimensional and 3-dimensional free surface flow models using recent cross-sectional geometry and data from an extreme flow event that occurred April 6, 2005. This report focuses on the data compiled for the model simulations. The Goodwin Creek bendway project encompasses many types of instrumentation for measurement of streamflow, sediment transport, streambank stability, and morphological change. The bendway instrumentation consists of numerous tensiometers at various depths within the streambanks to monitor pore-water pressure, pressure transducers for water level (stage) at upstream and downstream ends of the bendway, crest stage gages (at the same location as the pressure transducers) to record peak flow depth, two recording raingages, suspended sediment samplers at upstream and downstream ends of the bendway, and an acoustic sensor (EasyQ) at the downstream end of the model reach to record water level and velocities.