ORCID
0000-0001-8417-462X
Date of Award
2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Natural Resources
First Advisor
Paul R. Bierman
Abstract
Human environmental impacts have repercussions for present and future generations. Mismanaged landscapes catalyze soil erosion, water pollution, and slope instability. My research sits at the intersection of Earth surface processes, environmental justice, and education, exploring landscape change in fluvial systems on geologic and human timescales through three interdisciplinary research projects. In the first project, I used historic records and modern imagery to create an inventory of landslides along an incised river valley in urban Burlington, Vermont, USA. I found record of 20 landslide events between 1952 and 2024, occurring mostly in noncohesive fill materials emplaced at the top of a well-trafficked slope beginning in the 1930s. This project explores the unforeseen consequences of land use and environmental modification and underscores the importance of informed land management. Education about surface processes and hazards is an important aspect of improving environmental management on individual and systemic levels. However, many educational opportunities are not equitably accessible, and best-practice informed models for environmental research training are needed to increase accessibility. In my second project, I developed an immersive undergraduate environmental science education program and solicited participant feedback to evaluate the effectiveness of the program model. Participants suggested that the program effectively met goals of financial and academic accessibility, supportive mentoring environment, and professional network building, and could benefit from additional scaffolding of research methods. Informed by this feedback, the model provides a framework that others may use to develop similar programs. In my final project, I used in situ cosmogenic 10Be and stream water geochemistry data to estimate rates of erosion and rock dissolution in Puerto Rico, contributing to a growing body of literature on tropical mass transfer from land to sea. In SE Puerto Rico, I found that rock erosion and dissolution rates are comparable agents of mass flux, with respective mean rates of 144 and 147 Mg km⁻² yr⁻¹ and an average ratio of 1.2. Using in situ 10Be erosion rates derived from samples collected in 19 basins before and after hurricane Fiona, I found that calculated rates of erosion increased by 28.4 Mg km⁻² yr⁻¹ on average (range: -9.0 – 114.0 Mg km⁻² yr⁻¹), indicating a change in sediment source that measurably diluted cosmogenic 10Be concentrations in stream sediment. This shift was particularly significant in small basins (<2 km2) characterized by high relief (mean 345 m) and steep slopes (mean 24º). These findings indicate that rock dissolution is a significant driver of regional mass loss and support previous work suggesting caution when using fluvial 10Be concentrations to measure erosion rates in small basins following large storm events. These background rates of erosion can inform landscape management by providing a baseline to compare with impacts of human activity. Collectively, these projects contribute new insights regarding landscape change and emphasize the importance of both informed landscape management and broadening participation in Earth science. As human-environmental impacts increasingly alter landscapes and the global climate, the magnitude and frequency of hazard events is increasing. Mitigating these impacts requires scientists with diverse backgrounds and expertise, which in turn requires improving and increasing access and inclusion efforts that serve people with identities underrepresented in Earth science.
Language
en
Number of Pages
276 p.
Recommended Citation
Bennett, Isabella Beatrice, "Investigating Human-Landscape Interactions Through Historical Landslide Reconstruction, Educational Program Development, and Quantification of Tropical Denudation in Puerto Rico" (2025). Graduate College Dissertations and Theses. 2021.
https://scholarworks.uvm.edu/graddis/2021
