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Through my interactions and collaborations with many researchers at the University of Illinois and elsewhere, I have been able to participate at various levels of involvement with several research projects. Below are brief descriptions of some of the major projects I have been involved with, including related publications and conference talks associated with each project.

Velocity Mapping Tool (VMT)

Use of hydroacoustic technologies, especially acoustic Doppler current profilers (aDcp) for discharge measurements and mapping of three dimensional flow patterns has become more and more common in recent years. In a collaborative effort between the University of Illinois, and the USGS Illinois Water Science Center, we have been developing the Velocity Mapping Tool (VMT), custom aDcp processing and research analyses software. VMT allows for quick processing, visualization, and analysis of aDcp data for a variety of flow environments. 

Associated Presentations and Publications
  1. Parsons, D.R., P.R. Jackson, J.A. Czuba, F.L. Engel, B.L. Rhoads, K. Oberg, J.L Best, D.S. Mueller, K.K. Johnson, and J.D. Riley. Accepted. Velocity Mapping Toolbox (VMT): A processing and visualization suite for moving-vessel ADCP measurements. Earth Surface Processes & Landforms.

Morphodynamics of a Large River Meander Cut-Off

Massive floods on the Wabash River in June 2008 caused the river to cut off the main channel near Mackey Island, just upstream of the confluence with the Ohio River. This presents a unique opportunity to document a large meander cut off, including examining the sedimentation processes leading to the eventual plugging of the old channel. Detailed measurement of flow structure, deposition and erosion in and around the cut off channel will shed light on how these channels form. This work will greatly improve our understanding of the morphodynamics of cut off channels.

Associated Presentations and Publications
  1. Zinger, Jessica A., Bruce L. Rhoads and James L. Best. 2011. Extreme sediment pulses generated by bend cutoffs along a large meandering river. Nature-Geoscience. doi:10.1038/ngeo1260
  2. Zinger, Jessica A., Bruce L. Rhoads, James L. Best, Frank L. Engel, and Kory M. Konsoer. 2010. Mobilization of Floodplain Sediments by Chute Cutoffs on a Large River: Lower Wabash River Illinois-Indiana. Eos Transaction AGU Fall Meeting Supplement. Abstract EP31C-0753.
  3. Rhoads, Bruce L., Jim Best, Kevin K. Johnson, and Frank L. Engel. 2010. Fluvial Dynamics of a Chute Cutoff (or Two) along a Large Meandering River. 106th Meeting of the American Association of Geographers, Washington D.C.. Apr. 14-18, 2010.
  4. Rhoads, Bruce L., Jim Best, Kevin K. Johnson, and Frank L. Engel. 2009. Flow Structure and Channel Change in a ChuteCutoff along a Large Meandering River. Eos Transactions AGU Fall Meeting Supplement. 90(52). AbstractH41B-0883.

Shear Layer Dynamics in Large River Confluences

Taking flow measurements in a shear layer on the Wabash-White River Confluence
In this research, we are examining the flow structure of large river confluences, particularly confluent meander bends (CMB). Through detailed measurement of flow using Acoustic Doppler Velocimeters (ADCPs), we hope to document the occurrence and patterns of coherent flow structures within the shear layers of several CMBs. This includes attempting to measure the spatial lag of these structures through the deployment of anchored ADCP sensors. Questions we are seeking to answer are: (1) Are there coherent structures which travel along the shear layer in large confluences?; (2) What, if any patterns are present in the structures, including periodicity, size, and positioning?; (3) Do these structures maintain their shape and size throughout the shear layer? If not, how do they evolve? My role in this research is to assist in data collection and processing, as well as analysis of results.

For more information, see my colleague Kory Konsoer's webpage.

Copper Slough Ditch, Champaign, IL

Stream naturalization has become increasingly popular as river managers realize the need to improve aquatic habitats in highly impacted systems. A major goal of naturalization projects is to increase the geomorphic and hydraulic diversity in streams (i.e., flow depths, velocities, and substrate) to enhance biotic diversity. However, implemented designs must also perform as intended for a variety of flow conditions. A common technique is to construct riffle structures in a reach of river in the form of rock weirs. However in low-gradient systems with large amounts of fine bedload, the pools upstream from these structures can infill over time and fail to function according to design. A successful channel design should function at all expected flows in the system and be self-maintaining through time. Pool-riffle sequences are common features in natural rivers that are self-maintaining through a range of flows. This study evaluates the hydraulic performance of a pool-riffle design for straight, human-modified channel using 1D steady flow modeling.

Associated Presentations and Publications
  1. Rhoads, Bruce L., Jorge Abad, and Frank L. Engel. 2011. “Geomorphologically Based Design for Naturalizing Straight Channels.” In Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools. A. Simon, S. J. Bennett, J. M. Castro, and C. Thorne (eds.). AGU Monograph. 500pp.
  2. Engel, Frank L. Stream Naturalization Design: HEC-RAS Modeling of Pool-Riffle Structure Designs, Copper Slough Ditch, Champaign County, IL. Illinois Water Conference 2008, Champaign, IL. Oct. 8-9, 2008.

Geomorphic Characterization of the San Antonio River, Texas

Large river systems can consist of a variety of complex channel shapes and geomorphologic forms and features which create a diverse and complex array of physical habitats. In Texas the implementation of a state wide in-stream flow program has prompted the need to process and interpret the geomorphology and habitat in these complex systems. The San Antonio River watershed (~11,000 sq. km) has been indicated as a priority basin due to issues of water reuse and wastewater return flows. Geomorphic features form discrete habitats (e.g. pool, riffle, stream confluences) and therefore characterization and classification can be used as a surrogate for determining habitat and in-stream flow characteristics. This study evaluates a technique for characterizing the geomorphology of the Lower San Antonio River using a cluster algorithm to group river reaches together based on similarity of measured geomorphic process variables. The results using the cluster algorithm are evaluated against a non-statistical approach to characterize the river into geomorphologically significant reaches. Comparison between the cluster algorithm and non-statistical techniques shows a strong agreement in the results suggesting that the cluster algorithm approach may be a useful tool in beginning a thorough geomorphic analysis of large systems.

Associated Presentations and Publications
  1. Engel, Frank L. 2007. Geomorphic Classification of the Lower San Antonio River, Texas. Technical Report. Texas Water Development Board. Available online: ( 
  2. Engel, Frank L. 2007. Classification of the Lower San Antonio River Using a Multivariate Statistical Approach. Masters Thesis. Geography, Texas State University. San Marcos, TX.
  3. Engel, Frank L. Geomorphic Characterization of a Fluvial System Using Clustering Algorithms. 104th Meeting of the American Association of Geographers, Boston, MA. Apr. 14-19, 2008. 
  4. Engel, Frank L. Geomorphic Characterization of the Lower San Antonio River, Texas. West Lakes Regional Meeting of the American Association of Geographers, Urbana, IL. Nov. 7-9, 2007. 
  5. Engel, Frank L. Classification of the Lower San Antonio River Using Clustering Algorithms. Texas Fluvial Geomorphology Symposium, Austin, TX. June 8, 2007.

Channel Aggradation due to Flood Management Practices

In 1998, the San Marcos River, located along the Balcones Escarpment in Central Texas, experienced the largest flood in its recorded history. The San Marcos is a heavily managed watershed containing flood control dams, reaches of channelized flow, and a man made lake. This study examines changes to the fluvial system as a result of the combination of an extreme flow event and watershed management practices. The flood caused mass wasting and channel bed aggradation. Since the flood, watershed management practices and flood retention structures have reduced the ability of the flows to transport sediment through the channel. Results indicate that since flood control measures were implemented, only two flood events could have produced any significant transport of material in the study reach. The lasting effect has been an increase in the width to depth ratio in the downstream portion of the river and the creation of a large sediment bar in the upstream channel reach.

Associated Presentations and Publications
  1. Engel, Frank L. and J. C. Curran. 2006. Aggradation in Response to Extreme Flooding and Watershed Management. Eos Transactions AGU, Fall Meeting Supplement. 87(52). Abstract H51G-0571. 
  2. Engel, Frank L. and J. C. Curran. Effects of Flood Management Practices in the San Marcos River, Texas. 37th International Binghamton Geomorphology Symposium: The Human Role in Changing Fluvial Systems, Columbia, SC. Oct. 20-22, 2006. 
  3. Engel, Frank L. and J. C. Curran. Channel Bed Changes in Response to Control Structures on the San Marcos River, Texas. Texas Rivers and Reservoirs Management Symposium, Austin, TX. May 19-20, 2006. 
  4. Engel, Frank L. and J. C. Curran. Effects of Flood Control Structures on the San Marcos River, Texas. 2005 Environmental Flows for the Future Conference, San Marcos, TX. Oct. 31-Nov. 1, 2005.