Proceedings of the Seventh Federal Interagency Sedimentation Conference, March 25 through 29, 2001, Reno, NV Volume 1 I. Sediment and Flow Modeling Sediment and Flow Modeling Proceedings of the Seventh Federal Interagency Sedimentation Conference, March 25 through 29, 2001, Reno, NV I. Sediment and Flow Modeling TABLE OF CONTENTS Page ANNAGNPS: ESTIMATING SEDIMENT YIELD BY PARTICLE SIZE FOR SHEET AND RILL I – 1 EROSION: Ronald L. Bingner, USDA-ARS, NSL, Oxford, MS; and Fred D. Theurer, USDA-NRCS, Beltsville, MD A SEDIMENT TRANSPORT AND YIELD MODEL FOR ALLUVIAL STREAMS: L. J. Lane, I – 8 USDA-ARS, Tucson, AZ MODES OF SHALLOW AND DISPERSED PARTICULATE TRANSPORT IN SLOPING I – 16 CHANNELS: D. Pal and S. N. Prasad, U. of Mississippi, University, MS; and M. J. M. Römkens, USDA-ARS NSL, Oxford, MS TECHNIQUES FOR ESTIMATING SEDIMENT YIELD OF UNGAGED TRIBUTARIES ON THE I – 24 SOUTHERN COLORADO PLATEAU: Robert H. Webb, Peter G. Griffiths, and Daniel R. Hartley, USGS, Tuscon, AZ PREDICTION OF COHESIVE SEDIMENT TRANSPORT AND BED DYNAMICS IN ESTUARIES I – 32 AND COASTAL ZONES WITH INTEGRATED NUMERICAL SIMULATION MODELS: J. Berlamont, Katholieke Universiteit, Leuven, Belgium; K. Dyer, U. of Plymouth, U.K.; M. Markofsky, Universität Hannover, Germany; H. Michallet, Université Joseph Fourrier, Grenoble, France; O. Petersen, Danish Hydraulic Institute, Denmark; W. Roberts & M. Dearnally, H.R. Wallingford, U.K.; G. Sills, U. of Oxford, U.K.; E. Toorman, Katholieke Universiteit, Leuven, Belgium; D. Violeau, LNHE, Electricité de France; and H. Winterwerp, Delft Hydraulics and T.U. Delft, the Netherlands SMALL SCALE PHYSICAL SEDIMENT TRANSPORT MODELING APPROACH USED TO I – 40 SOLVE A CHRONIC DREDGING PROBLEM ON THE ATCHAFALAYA RIVER AT MORGAN CITY, LOUISIANA: David C. Gordon and Robert D. Davinroy, USACE, St. Louis, MO; James W. Austin, USACE, New Orleans, LA NUMERICAL MODELING OF DYNAMIC RIVER ADJUSTMENT: Blair Greimann, USBR, I – 47 Denver, CO; Chih Ted Yang, USBR, Denver, CO; and Drew Baird, USBR, Albuquerque, NM MODELING OF SEDIMENTATION PROCESSES IN CHANNEL NETWORKS: Dalmo A. Vieira, I – 55 Weiming Wu and Sam S.Y. Wang, The University of Mississippi, NCCHE, University, MS THREE-DIMENSIONAL SIMULATION OF SEDIMENT TRANSPORT IN SCOURING PROCESS: I – 63 Yafei Jia and Sam S. Y. Wang, The University of Mississippi, NCCHE, University, MS APPLICATION OF CCHE2D MODEL TO FLOW SIMULATION IN LOCK AND DAM: Abdul A. I – 70 Khan, Sam S. Y. Wang, National Center for Computational Hydroscience and Engineering, University of Mississippi. APPLICATION OF AERIAL INFRARED VIDEOGRAPHY AND A 2-DIMENSIONAL FLOW I – 77 MODEL TO INVESTIGATE SANDHILL CRANE ROOSTING HABITAT ALONG THE PLATTE RIVER, NEBRASKA: P. J. Kinzel, J. M. Nelson, and R. S. Parker, USGS, Lakewood, CO THREE-DIMENSIONAL MODELING OF FLOW THROUGH SPARSE VEGETATION: Francisco I – 85 J. M. Simões, USBR, Denver, CO Proceedings of the Seventh Federal Interagency Sedimentation Conference, March 25 through 29, 2001, Reno, NV SEDIMENT IMPACTS OF PROPOSED MODIFICATIONS TO THE RIO GRANDE AND LOW I – 93 FLOW CONVEYANCE CHANNEL BELOW SAN MARCIAL: Christi Young, USBR, Denver, CO; Cassie Klumpp, USBR, Denver, CO; and Drew Baird, USBR, Albuquerque, NM EVENT BASED SEDIMENT TRANSPORT SIMULATION OF A RIVER REACH UPSTREAM OF I – 101 A TEMPORARY DREDGE CHANNEL, ELEPHANT BUTTE DAM, NEW MEXICO: Robert S. Padilla, USBR, Albuquerque, NM; and Richard Heggen, University of New Mexico, Albuquerque, NM SEDIMENTATION ANALYSIS--PANOLA-QUITMAN FLOODWAY, MISSISSIPPI: Michael J. I – 107 Trawle, Basil K. Arthur, and Larry E. Banks, USACE, Vicksburg, MS SAND TRANSPORT AND BED EVOLUTION MODELING APPLICATIONS IN THE COLORADO I – 115 RIVER, GRAND CANYON: Stephen M. Wiele and Margaret A. Franseen, USGS, Denver, CO EVALUATING SELECTED SCOUR EQUATIONS FOR BRIDGE PIERS IN COARSE I – 120 STREAMBEDS IN NEW YORK: Laurence J. Welch, Jr., and Gerard K. Butch, USGS, Troy, NY BRIDGE ABUTMENT EROSION PROBLEM SOLVED WITH A SMALL SCALE PHYSICAL I – 128 SEDIMENT TRANSPORT MODELING APPROACH: David C. Gordon and Robert D. Davinroy, USACE, St. Louis, MO SUSPENDED SEDIMENT BUDGET AND YIELDS FOR THE LAGRANGE POOL OF THE I – 136 ILLINOIS RIVER, OCTOBER 1994--SEPTEMBER 1997: Gary P. Johnson, USGS, Urbana, IL EVOLUTION AND TIMING OF SUSPENDED-SEDIMENT TRANSPORT FOLLOWING THE 1980 I – 137 MOUNT ST. HELENS ERUPTION: Jon J. Major, USGS, Vancouver, WA MIXED-SIZE SEDIMENT TRANSPORT MODEL FOR NETWORKS OF ONE-DIMENSIONAL I – 145 OPEN CHANNELS: James P. Bennett, USGS, Denver, CO SPACING OF STEP-POOL SYSTEMS IN GRAVEL-BED RIVERS: A. R. Maxwell and A. N. I – 153 Papanicolaou, Washington State U., Pullman, WA THE USGS MULTI-DIMENSIONAL SURFACE WATER MODELING SYSTEM: R. R. McDonald, I – 161 J. P. Bennett, and J. M. Nelson, USGS, Denver, CO ECO-HYDRAULIC MODEL APPLICATION IN A STEEP RANGELAND WATERSHED: Shawkat I – 168 Ali, Peter Goodwin, and Charles W. Slaughter, U. of Idaho, Boise, ID CHARACTERISTICS OF FLOW AND EROSION IN A NATURAL STREAM WITH LOESS-TYPE I – 176 BANKS: Rob Hilldale and Athanasios Papanicolaou, Washington State U., Pullman, WA APPLICATION OF MODIFIED EINSTEIN METHOD USING INCREMENTAL CHANNEL I – 184 GEOMETRY: Patrick S. O'Brien, USACE, New Orleans, LA; and Alex McCorquodale, U. of New Orleans, LA EVALUATION OF SELECTED BEDLOAD EQUATIONS UNDER TRANSPORT- AND SUPPLY- I – 192 LIMITED CONDITIONS: Vicente L. Lopes, U. of Arizona, Tuscon, AZ; W. R. Osterkamp, USGS, Tuscon, AZ; Miguel Bravo-Espinosa, Centro Nacional de Investigacion para Produccion Sostenible, Morelia, Mexico WHAT REGULATES SUSPENDED-SEDIMENT TRANSPORT IN A GIVEN SETTING? GRAIN I – 199 SIZE OF BED SEDIMENT OR FLOW?: David M. Rubin, USGS, Santa Cruz, CA; and David J. Topping, USGS, Reston, VA Proceedings of the Seventh Federal Interagency Sedimentation Conference, March 25 to 29, 2001, Reno, Nevada AnnAGNPS: ESTIMATING SEDIMENT YIELD BY PARTICLE SIZE FOR SHEET & RILL EROSION By: Ronald L. Bingner, Agricultural Engineer, National Sedimentation Laboratory-Agricultural Research Service-USDA, Oxford, MS and Fred D. Theurer, Agricultural Engineer, National Water & Climate Center-Natural Resources Conservation Service-USDA, Beltsville, MD ABSTRACT: RUSLE (Revised Universal Soil Loss Equation) is the basis within AnnAGNPS (Annualized AGricultural Non-Point Source Pollution watershed model) for estimating sheet and rill erosion (clay, silt, sand, small and large aggregates) of a watershed’s landscape. This sheet and rill erosion is used to predict the sediment yield (clay, silt, and sand) from the watershed landscape by AnnAGNPS, which is a continuous-simulation, agricultural-related, non-point source, pollutant loading watershed model. The fine sediment yield (clay and silt) from sheet and rill erosion of agricultural lands is a major concern for pollutant loadings into water bodies, such as streams and channels. While other sources of sediment (gullies, bed, and bank erosion) are also predicted by AnnAGNPS, RUSLE is used only to estimate the sheet and rill erosion. A simple procedure to estimate the sediment delivery by particle size is necessary to link the sheet and rill erosion to the sediment yield in water bodies. Determining the sediment yield by particle size from each homogenous land area within the watershed (defined as a cell in AnnAGNPS) is critical in assessing the effectiveness of best management practices. The application of RUSLE is used to determine where and when sheet and rill erosion can occur. Algorithms within RUSLE for irregular and segmented slopes are defined in the USDA Agricultural Handbook Number 703, and can be used to determine a raster-weighted LS-factor for each homogenous land area. The delivery ratio procedure in AnnAGNPS is based upon HUSLE (Hydro-geomorphic Universal Soil Loss Equation) and the respective fall velocities of the particle-size classes predicted by RUSLE. The results show that most coarse sediment (sand-size particles) deposit in the fields while most fine sediments (eroded clay and silt size particles that become entrained in the runoff) become wash load and enter the streams and channels. INTRODUCTION AnnAGNPS is the pollutant loading (PL) model within a suite of computer models that is designed to analyze the impact of non-point source pollutants from predominately agricultural watersheds on the environment (Cronshey and Theurer, 1998; Theurer et al, 1999). This suite of computer models is called AGNPS 98 and can be located on the Internet at: “http://www.sedlab.olemiss.edu/AGNPS98.html” The pollutant loading most frequently of concern to conservationist dealing with agricultural watersheds is fine sediment generally originating from sheet and rill erosion. AnnAGNPS predicts: (1) water; (2) sediment by particle size from sheet and rill, gully, and stream bed and bank; and (3) chemicals from the landscape. Although AnnAGNPS predicts all of these pollutant loadings, this paper will concentrate on the prediction of sheet and rill erosion and subsequent sediment yield. This paper will briefly describe how predictions are made for: (1) sheet and rill erosion (RUSLE); (2) delivery ratio for the sheet and rill erosion to determine sediment yield to receiving reaches of the stream system (HUSLE); and (3) particle-size distribution for the delivered sediment yield to the stream system from sheet and rill erosion. And finally, a comparison of measured sediment data to predicted will be made. An extremely important point for watershed modeling is that AnnAGNPS predicts the average erosion and subsequent sediment yield from each field or cell in the watershed,