Date of Completion

2021

Document Type

Honors College Thesis

Department

Department of Civil and Environmental Engineering

Thesis Type

Honors College

First Advisor

Eric Roy

Second Advisor

Kristen Underwood

Third Advisor

Breck Bowden

Keywords

wetland, HydroCAD, Vermont, beaver dam, hydrology, phosphorus

Abstract

Phosphorus (P) is an important nutrient in ecosystems and is often limiting in freshwater systems and the human application of P in agriculture has made P management a priority to maintain freshwater ecosystem health. Previous studies suggest that small wetlands play a disproportionately large role in landscape-scale nutrient processing. Modeling watershed P dynamics requires estimates of water budgets within the areas of interest. The objective of this work is to model the inflow, outflow, stage, and storage relationships of a small wetland with an active beaver dam in the Prindle Brook floodplain in Addison, VT using HydroCAD. A sensitivity analysis was performed to assess how various parameters, such as curve number, antecedent moisture condition, and the length of storms affect results. The sensitivity analysis also addressed the outlet structure which represents an active beaver dam. Limited research has been published with guidance for modeling a beaver dam in HydroCAD. Changing the parameters in the sensitivity analysis had a much larger effect on smaller storms than larger ones. Antecedent moisture conditions affected the peak inflow, outflow, and water level values while changing the length of storms altered the time to peak. Altering the outlet structure changes the water level within the wetland and how quickly it drops but does not generally change the peak outflow. This model will be coupled with a P model to understand P dynamics in restored riparian wetlands on former agricultural land during flood events. These results will be important for recommendations to the state and non-profit agencies about how to best prioritize potential restoration sites.

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.

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