Date of Completion

2023

Document Type

Honors College Thesis

Department

Environmental Sciences

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

Beverley C. Wemple

Second Advisor

Cheryl E. Morse

Third Advisor

Ana M. Morales-Williams

Keywords

headwater streams, first-order streams, restoration, geomorphology, hydrology

Abstract

Headwater streams, comprising as much as 80% of river networks, substantially influence the hydrological regimes, ecological character, and sediment and nutrient fluxes associated with the river networks in which they exist. Historic stream degradation across the United States, however, has altered the geomorphology of streams, consequently compromising their ability to store incoming nutrients and water as well as foster healthy ecological communities. Process- based restoration (PBR) approaches have been increasingly implemented to address the needs of degraded streams. Twenty-nine in-stream woody structures were installed in a degraded headwater stream in northwestern Vermont to reduce water velocity, induce streambed aggradation, and restore floodplain connectivity. The structures, along with 12 cross-sections of the stream, were monitored over the course of a year to assess the capacity of the structures to cause geomorphic changes in the channel. A repeated LiDAR survey of the study site also provided information on channel changes after one year. These data show that about one-third of the cross-sections experienced notable streambed aggradation, and lateral migration was also observed in some locations. Most installed structures remained intact over the duration of the study period, though their efficacy diminished with time. These results not only have implications for the form and function of this stream, but also for the role of PBR in the greater context of river restoration, particularly in headwaters. The low-tech nature of this practice also presents the opportunity for community involvement in river restoration.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Wednesday, June 05, 2024

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