Water Resources Research Act Program

Details for Project ID 2017TN131B

Characteristics of Fine Sediment Embeddedness: Towards Understanding Drainage Network Transport Lags

Institute: Tennessee
Year Established: 2017 Start Date: 2017-03-01 End Date: 2019-02-28
Total Federal Funds: $8,000 Total Non-Federal Funds: $18,972

Principal Investigators: John Schwartz

Project Summary: The State of Tennessee contains many waterbodies that have been identified on the 303(d) list as impaired or threatened, by which they do not meet designated beneficial uses including biological integrity [40 CFR Part 130; TCA 69-3-101 and TDEC Rules Chapter 1200-4]. A majority of streams listed are impacted by excessive sedimentation in channels causing physical habitat degradation, thus reducing biological integrity. The Tennessee Department of Environment and Conservation (TDEC) is required by statutes to produce total daily maximum loads (TMDLs) for 303(d) listed streams impacted by siltation and habitat alteration. Watershed impacts from excessive sedimentation are an international issue, including the Czech Republic. Colleagues at the Czech Technical University (CTU), Civil Engineering Faculty are interested in collaborating on sediment transport and channel erosion problems. We have agreed to investigate sediment dynamics in the channel associated with embeddedness, where fine sediment (silt or smaller) becomes embedded into alluvial channel materials consisting of mixed bedload. The focus of this research will be assessing the role of biofilms associated with the retention of fine sediment into the channel bed alluvium. A McNeil sediment sampler will be used to sample bed material without the loss of the fine sediment fraction, in which the samples will be analyzed for particle size fractions and organic content. Sediment collections will be co-located conducted at sites with Tennessee benthic macroinvertebrate index (TMI) bioassessment data. In addition, field experiments will be conducted examining the influx of fine sediment into a standard gravel matrix, in a specially constructed sampling device placed on the stream bed. This research project will be conducted by an undergraduate student over the summer period (May-August 2017). Similar research will be conducted on a research stream by the CTU. For the long-term, Dr. Schwartz will use this CTU collaboration to publish a peer-reviewed journal article, and start building the case for a future National Science Foundation (NSF) Partnership for International Research and Education (PIRE) grant. As hypotheses, the expected outcomes include a statistically significant response that biofilms play a key role in embeddedness, embeddedness quantified by a McNeil sampler will be correlated to TMI scores and directly correlated with biological impairment, and development of a relationship of fine sediment influx into a gravel matrix, used towards predicting embeddedness in streams.