Wednesday, November 15, 2006 - 3:35 PM

Assessing the Impact of Riparian Buffer Systems on Streambank Stability Using the CONCEPTS Channel Evolution Model.

Eddy J. Langendoen, USDA-ARS National Sedimentation Laboratory, 598 McElroy Dr, Oxford, MS 38655

Many federal, state, and local organizations are active in restoring damaged channel systems or assessing sediment TMDLs for sediment-impaired streams.  A particular challenge we face today is the lack of integrated, comprehensive modeling tools to evaluate the long-term response of restored stream-riparian corridors, and the long-term effectiveness of BMPs for instream sediment source reduction.  Any restoration design needs careful scrutiny because it long-term impact on corridor response is not easy to predict, and the cost of computer modeling is small compared to the cost of prototype failure.


The CONCEPTS (CONservational Channel Evolution and Pollutant Transport System) computer model has been developed among others to evaluate stream-corridor restoration designs.  CONCEPTS simulates channel evolution by tracking bed changes and channel widening.  Bank erosion accounts for basal scour and mass wasting of cohesive banks.  CONCEPTS simulates transport of cohesive and cohesionless sediments, both in suspension and on the bed, and selectively by size classes.  It can predict the dynamic response of flow and sediment transport to instream structures.  Recently, technology from the USDA-ARS Riparian Ecosystem Management Model (REMM) has been integrated with CONCEPTS.  REMM estimates the nonpoint source pollution control by field-scale riparian ecosystems and the evolution of these ecosystems.  The integration has a resulted in a comprehensive stream-riparian corridor model that can be used to assess the effects of riparian buffer systems and forests on stream stability.

 CONCEPTS has been applied to simulate channel morphology and response in diverse environments.  It has been used to study mitigation strategies in disturbed channels with both cohesive and cohesionless bed materials in Alabama, California, Michigan, Mississippi, Nebraska, and New Mexico.