Comparison of Hydraulic Function and Channel-Floodplain Connectivity Between Actively and Passively Restored Reaches of Stroubles Creek 11 Years After Restoration

A hydraulic model was developed to determine differences in the hydraulic characteristics of three different reaches of an urban- and agriculturally-impacted stream in southwest Virginia. The three reaches all had cattle excluded from the channel in 2010. The farthest upstream, Treatment 1, was left to progress without intervention beyond cattle removal while the other two, Treatments 2 and 3, were regraded and stabilized using common stream restoration techniques and a forested riparian was established. The banks of Treatment 2 were regraded to a slope of 3:1 while Treatment 3 was designed with a flat inset floodplain cut into the banks. The model results showed that the self-adjustment in Treatment 1 exhibited inset floodplains with diverse topographical structure including floodplain channels. These adjustments provided higher floodplain volume and mass exchange between the channel and the floodplain when compared with the stable, straight Treatment 2. Comparisons between Treatment 1 and Treatment 3 did not clearly show which treatment was more well connected, with some metrics showing Treatment 1 was more connected while others indicated the opposite. Overall, the findings indicate that stabilization of channelized streams without consideration of the natural planform prolongs adjustment to a channel-floodplain form with more exchange of water, sediment, nutrients and providing refuge for biota.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biological Systems Engineering

Department dc:contributor.department

Biological Systems Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2022

Author dc:creator

• Christensen, Nicholas Daniel

Chair dc:contributor.committeechair

• Czuba, Jonathan A.

Committee members dc:contributor.committeemember

• Hession, W. Cully
• Strom, Kyle Brent

• Stream Restoration
• Passive restoration
• Stream Hydraulics
• Fluvial Geomorphology

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:35028

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/110935