Digital Commons Network^™

Pesticides And Poverty: How Socioeconomic Factors Relate To Pesticide Application In The Continental Us, Reed Smetter

Theses and Dissertations

Pesticides are often used to help reduce the populations of weeds, insects, and pathogens in agricultural and urban settings, reducing the risk of outbreaks and losses of agricultural yield. The communities that surround agricultural areas often bear the brunt of the negative community and environmental health effects of these chemicals, and are frequently rural, poor, and lack critical infrastructure resources. Pesticide application volumes are often linked closely with specific health effects. In this study, I apply social vulnerability theory to compare the potential connections between the application rates of pesticides and socioeconomic variables across the United States using a nationwide …

Spatiotemporal Evolution Of Flow Decline And Water Consumption In A Highly Regulated Transboundary River: The Lower Rio Grande/Bravo, Ana Yarely Casillas Rodriguez

Theses and Dissertations

Long-term flow variability in transboundary rivers reflects the combined influence of water availability, infrastructure development, and binational water use. Integrating historical discharge with evolving water-use data remains challenging due to fragmented records and nationally bounded assessments. This study reconstructs a 125-year discharge record (1900–2025) from historical Water Bulletins and modern observations at 12 gauging stations, providing a spatiotemporal assessment of flow evolution and water-budget components in the Lower Rio Grande/Bravo (LRG).

Discharge records were grouped into four hydrologic regimes—natural (1900–1913), pre-dam (1935–1950), post-dam (1974–1989), and modern (2010–2025)—and analyzed alongside binational water-use data across major sectors. A basin-scale water budget, using …

Soil Water Content Beneath Agrivoltaic Installations In A Subtropical Semi-Arid Climate, John Justin Rodriguez

Theses and Dissertations

Agrivoltaics (AV) not only beneficially influences agricultural microclimates in the field, AV systems can generate on-site energy to offset operational costs, diversify income sources, and improve overall resilience, while providing environmental co-benefits such as reduced heat stress on plants and improved resource use efficiency. This thesis evaluated agrivoltaic shading effects on SWC and soil temperature using high-resolution in situ measurements collected over one year in an active vineyard, incorporating row type, soil depth, shading, and time of day. With precipitation as the primary water source, shaded soils exhibited up to 24.53% lower SWC relative to sun-exposed soils, likely due to …

Post-Wildfire Erosion And Biogeochemistry: Integrating Aerial Imagery And Soil Testing To Assess Landscape Recovery, Justin A. Allred

All Graduate Theses and Dissertations, Fall 2023 to Present

After a wildfire, land managers are required to monitor large tracts of land with limited time and budgets. Traditionally, tracking landscape recovery is a time intensive process. This research explored the effectiveness of using drones (UAVs), strategic soil sampling, and computer modeling as additional tools for land managers in order to monitor the recovery more efficiently.

By using drones to collect aerial imagery and using machine learning, plant regrowth was monitored in back-to-back years. The machine learning model performed well at telling broad groups apart (trees vs grass) but it struggled to identify differences between plant species. Because many plants …

On The Paleontology Of Belize, Alson Ovando

Electronic Theses and Dissertations

Paleontology can be considered an underrepresented and emerging area of science in Belize. A primary aim of this thesis is to provide a background of paleontology in Belize and present the first comprehensive study of Quaternary vertebrate fossils known from the country. Quaternary fossil sites across Belize include caves, rivers, and sinkholes. In addition to reviewing and assessing material from known sites, this thesis presents new information and discoveries that were made while investigating Belize’s Quaternary fossil record. This thesis also includes a geospatial model depicting ecoregions in Belize during the last glacial maximum. Overall, the results presented here demonstrate …

Environmental And Structural Drivers Of Hurricane Edouard (2014) Intensification, Elizabeth Smith

Atmospheric and Environmental Sciences Honors Program

Forecasting tropical cyclone (TC) intensification remains challenging due to the complex kinematic and thermodynamic processes that control storm evolution. This study examines the structural and environmental changes associated with the intensification of Hurricane Edouard (2014) by analyzing multiple observational datasets during its development. The analysis is divided into four categories: (1) environmental moistening, evaluated using dropsonde and aircraft flight-level data; (2) vortex structure, examining changes in the storm’s circulation and organization; (3) convective structure, assessed through radar and satellite observations; and (4) lightning bursts, using lightning detection data in the storm’s outer and inner rainbands. By comparing the timing of …

Quantifying Macrophyte Ecosystem Services And Improving Environmental Nonprofit Messaging, Peyton R. Hughey

All Theses

Environmental nonprofits are essential to the management and restoration of our natural spaces. They are also tasked with engaging the public via outreach, education, and advocacy. As natural spaces are degraded, the ability of environmental nonprofits to deliver on their missions will become increasingly important. This study aimed to improve two approaches to environmental nonprofits’ missions: ecological restoration and social media communication.

Environmental nonprofits operate with limited resources, and ecological restoration can be an exhaustive task; therefore, we explore functional restoration as a tool. In this study, we focus on the use of functional, trait-based restoration to restore ecological function …

Low Methane Emissions From Nutrient-Rich Former River Channels In A Hydrologically Managed Dryland Delta, Siena Stassi, Jude A. Benavides, Chu-Lin Cheng, Marcelo Gomes Da Silva, Nicholas E. Ray, Nathan O. Barros, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Anthropogenic stresses in dryland regions can alter hydrology, salinization, and biogeochemical processes. How these pressures influence methane (CH4) cycling and emissions from aquatic ecosystems remains poorly understood. Over the course of 1 year, we measured diffusive and ebullitive CH4 emissions from resacas—shallow, hydrologically managed distributary channels prevalent throughout the Lower Rio Grande Valley along the US–Mexico border. Despite warm, nutrient-rich waters, CH4 emissions from resacas were low, and more comparable to rates observed in estuarine systems. CH4 fluxes were positively related to temperature but negatively related to salinity and rainfall. Elevated salinity, driven by evaporation and source water from the …

Landscape Connectivity And Wildlife Access To Water Across An International Border: Barriers And Opportunities For Facilitating Transboundary Movement, Bogdan Chivoiu, Erin L. Koen, Michael J. Osland, Christopher A. Gabler, Jerald T. Garrett, Ernesto Reyes, Stephanie A. Bilodeau, Mitch A. Sternberg, Jude A. Benavides, James Martinez

School of Earth, Environmental, & Marine Sciences Faculty Publications

Rapid global acceleration in the construction of physical barriers along international borders has greatly influenced biodiversity and animal movement. Physical barriers can fragment landscapes, hinder access to essential resources, impact long-distance migrations, and inhibit dispersal and gene flow. The effects of physical barriers on animal movement and landscape connectivity can be exacerbated in dryland environments where access to water is a limiting factor. In recent decades, the construction of border barrier infrastructure has accelerated along the international boundary between the United States and Mexico. Here, we used a landscape connectivity model to investigate the effects of barriers on wildlife access …

The Impact Of Label Material On Perceived Value And Environmental-Friendliness Of Beverages In Returnable Glass Bottles Versus Actual Environmental Impact Via Life Cycle Assessment, Toni Sharp

All Dissertations

With guidance from the EPA to reduce virgin packaging use and alternatively increase reuse, the concept of reusable packaging has re-emerged as a potential sustainable alternative to single-use and recyclable packaging. For businesses, an understanding of the potential environmental benefits of switching from single-use packaging to reusable packaging, along with consumer willingness to pay for sustainable packaging are paramount. Existing literature on willingness to pay (WTP) for ethical or sustainable products typically relies on consumers’ stated preferences found through surveys using hypothetical products and prices. It has been revealed that sustainability claims printed on the label or products in glass …

Detecting Sophisticated Cyberattacks On Public Water Infrastructure, Ayrton Purdy

Graduate Theses and Dissertations (2019 - present)

In recent years there has been an increasing number of cyberattacks on public water generation and distribution systems. Advanced persistent attackers could usurp sensors and control systems to contaminate public drinking water. In order to conceal their malicious activity, they can manipulate sensor data flows to give the appearance of normal activity. The compromised sensors would report normal chemical levels even though unsafe water is entering the distribution system. In response, this research proposes a multi-sensor, cross-comparison approach to anomaly detection. The proposed approach is designed to detect sophisticated cyberattacks which are not easily detectable using traditional cyber tools. The …

Passive Microwave Remote Sensing Of Flash Drought Impacts On Vegetation, Quinton R. Deppert

School of Natural Resources: Dissertations, Theses, and Student Research

In 2002, Dr. Mark Svoboda characterized a new form of drought known as flash drought. Flash drought was defined as a rapid decline in vegetation health caused by severe heat and drought. In recent years, attempts to quantify the impacts of flash drought via precipitation, soil moisture, evapotranspiration, and temperature indicators have proliferated. What has rarely been quantified is what the rapid decline in vegetation health amid flash drought looks like through remote sensing. This is because vegetation health indices like the Normalized Difference Vegetation Index (NDVI) are derived from the visible and infrared regions of the electromagnetic spectrum and …

Plant Communities Of Arid Ephemeral Stream Streams, Biogeographic Filters, Climatic Sensitivity, Urban Impacts Across Spatial And Temporal Scales, Luis Miranda

Open Access Theses & Dissertations

Ephemeral stream networks, locally known as arroyos, are among the most ecologically significant yet least protected habitats in arid landscapes. Despite supporting a disproportionately high plant biodiversity compared to surrounding uplands, these riparian systems lack regulatory protection in most arid U.S. states and face increasing pressure from urban expansion and intensifying climate change. There is an urgent need to understand how these factors influence riparian plant communities and hinder their ability to recover, enabling effective conservation and management strategies. In this dissertation, I explored the interplay of biogeographic gradients, precipitation variability, and urbanization in shaping arroyo riparian plant communities across …

Environmental Movements In El Paso And Ciudad Juarez: Possibilities And Limitations Of Cross-Border Organization At The U.S.-Mexico Border, Vanessa Maria Almada

Open Access Theses & Dissertations

At the U.S.-Mexico border, the anthropogenic and nationalistic construction of the landscape has accelerated urbanization and unequal development without establishing effective binational institutions for governance over a shared commons. Borderlanders, then, contest unsustainable development with the added complexity of navigating a barrier which creates diverse socioeconomic and political realities that challenge cross-border cooperation. This qualitative research analyzes environmental organizations in El Paso and Ciudad Juarez. Through ethnographic study of mobilization in response to environmental legislation and administrative action in each city, the immediate barriers to cross-border cooperation and limitations of nationalistic institutions in the borderlands can be better understood.

Exploring Connectivity And Element Distribution In The Critical Zone Using Deep Cores Below Agricultural And Natural Drylands In The American Southwest, Angie Lynette Cano

Open Access Theses & Dissertations

Water movement controls how solutes are transported and stored in arid Critical Zone (CZ) systems. In natural drylands, low precipitation and high evapotranspiration lead to long term salt accumulation in the CZ, whereas irrigation increases water input and increases downward solute transport. This study investigates how agricultural practices alter subsurface hydrology and geochemistry by comparing two deep CZ cores from the southwestern United States: a 50 m deep core beneath a flood irrigated pecan farm named 5R farm, in the Rio Grande Valley in Tornillo, Texas, and a 97.5 m deep core from the Red Lake Playa in the Jornada …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Advancing Apparel Education Through 3d Simulation In Vstitcher: Confidence, Competence, And Career Readiness In Higher Education, Jonah Diniakos Graham

Graduate Theses and Dissertations

The rapid adoption of 3D garment simulation in the apparel industry has created new demands of higher education to better prepare students with both technical proficiency and confidence within digital design platforms to better enable them for many career avenues. This study examines the integration of Browzwear’s VStitcher in an undergraduate apparel production course, addressing the need to assess both competence and self-confidence in digital garment construction while also fostering broader career readiness competencies. Guided by a combination of Self-Determination Theory (SDT) and Situated Expectancy-Value Theory (SEVT), the study emphasizes the role of autonomy, competence, and relatedness in the shaping …

Evaluating The Rural/Urban Divide In Conservation: Methods Of Improvement In Conservation Programming Across Kentucky, Lauren Tackett

Honors College Theses

Kentucky’s lands and waterways have always defined the state. Our unique karst landscape, combined with the Appalachian Mountains and Ohio River, help characterize the state and its identity. However, across Kentucky conservation efforts within recent years have been under attack. Through legislation changes and policy challenges, various bills have sought to repeal Kentucky’s conservation efforts regarding water, soil, and land use. Furthermore, there has been a rise in environmental disasters within the state that cause long term issues for both rural and urban communities to contend with. The responsibility of land stewardship falls on a variety of entities but weighs …

Microplastic Composition And Exposure Pathways In Freshwater Systems: A Multi-Matrix Comparison Between Streams And Retention Ponds In Hamilton County, In, Mya Whaley

All-Inclusive List of Electronic Theses and Dissertations

Since the early 1900s, the use of plastics has increased exponentially. The breakdown of plastic materials has exposed all ecosystems to microplastics (small particles of plastic < 5 mm), which are now ubiquitous in natural settings. Microplastics have a relatively large surface area, and many chemicals adsorb to these small particles, impacting their fate and transport of pollution. While microplastics have been found in virtually every setting on Earth, research is necessary to understand their impact on freshwater ecosystems and biogeochemical cycles. The focus of this research was to investigate microplastic compositions in crayfish, sediments, and water samples collected in streams and retention ponds. We analyzed trends in microplastic counts across different land-cover classes, waterbody types, and species, and compared concentrations among matrices to improve our understanding of microplastic exposure pathways in freshwater ecosystems. As a secondary objective, lead and arsenic concentrations were analyzed from sediment samples to investigate metal burdens and compare them to microplastic concentrations. Our findings revealed that, in general, urban streams had the highest microplastic concentrations within land cover categories, and retention ponds had higher microplastic counts than streams. Crayfish, such as F. rusticus had higher microplastic concentrations than F. virilis and F. propinquus, although these results may be influenced by study design. The most common microplastic type was fibers, and most common color was transparent. There was no significant correlation between microplastic and metal concentrations in sediments. We found crayfish to be adequate bioindicators of microplastic pollution, because they were less impacted by environmental variability than sediment and water samples. This research presents the first evidence of microplastics in our study species, F. propinquus, F. rusticus, and F. virlis. This work presents new evidence of microplastic accumulation in crayfish, sediments, and water from freshwater systems in the Midwestern United States. Microplastics were found in every sample type—crayfish, water, and sediment—across urban, rural, and forested landscapes, highlighting their pervasive distribution. The findings provide foundational data for assessing emerging ecological and human-health risks and emphasize the importance of sustained monitoring and research on MP contamination in freshwater environments.

Draft Final Annual Operations And Maintenance (O&M) Report: Butte Treatment Lagoon (Btl) System – 2025, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Silver Bow Creek Conservation Area Materials Management Plan, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Revised Silver Bow Creek Conservation Area (Sbcca) Construction Quality Assurance Plan (Cqap), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Feasibility Study Of Transitioning From Thick Plates (0.250”) Mounted On 30-Point Pvc Carriers To Thinner Plate Technologies Mounted On Recyclable Foam And Pet (0.155”) For Post-Print Corrugated, Nathaniel J. Poole

All Theses

In the United States, the most common press configuration for brown-box printing is a 0.280” undercut press. These press configurations have long relied on thick 0.250” plates mounted on 0.030” PVC sheets to print onto corrugated substrates. Each year, around twenty million pounds of waste are produced by the printing industry, through paper waste, plate waste, among other materials. One large factor of that waste is flexographic plate waste, which either ends its life in a landfill or is repurposed into other products. This study establishes a comparison between traditionally used 0.250” plates on 30pt PVC versus 0.155” plates mounted …

Environmental Sustainability Assessment Of Field Phosphate Monitoring Methods For Creeks, Quintino Medi

All Theses

Creeks serve as conduits for water, nutrients, and contaminants to larger water bodies such as rivers and lakes, and their health is a key indicator of overall watershed water quality condition. Unlike rivers, creeks are under-monitored due to their small size, hydrological variability, and limited accessibility. Many technologies exist for monitoring phosphorus in surface waters. Technologies may be classified into two general categories: i) proxy real-time sensors, which record generic water quality parameters, and ii) chemical reagent-based assays, which quantify soluble reactive phosphorus (SRP) in batch samples. There is a lack of studies that compare the features and benefits of …

Regional Assessment Of South Texas Wells Produced Water, Hunter T. Barnett

Water Resources Science and Technology Theses and Graduate Research Reports (Archived)

This study presents a regional assessment of produced water (PW) quality from oil and gas wells in South Texas, with a focus on variability and its implications for treatment and reuse. As oil and gas production continues to expand, PW waste streams will continue to grow. With a focus on the Eagle Ford Shale, understanding the chemical composition is critical for effective PW management. A total of 28 PW samples were collected from wells located in Pleasanton, Jourdanton, and Tilden, Texas. Samples were analyzed for key parameters including total dissolved solids (TDS), chloride, total hardness, and calcium. The results showed …

Assessment Of Mississippi Landfill Capacity In Relation To Waste Generation And Land-Use Constraints, Jason C. Anderson

Master's Theses

Municipal solid waste (MSW) management presents a growing challenge in Mississippi as population trends, socioeconomic change and regional development continue to place pressure on existing landfill capacity. This thesis examines waste generation and disposal patterns from 2000 through 2022 across Mississippi counties, with projections extending to 2050. Historical landfill tonnage data was gathered and compiled from the Mississippi Department of Environmental Quality (MDEQ) and analyzed using regression models in Excel and RStudio, with forecasts generated for both in-state and out-of-state waste flow. Results highlight significant variations among landfills, including differing closure timelines, changing county service areas and notable shifts in …

Quantifying Discard Mortality Of Undersized And Ovigerous Crabs In The Gulf Of Mexico Blue Crab Fishery, Micayla Cochran

Master's Theses

Blue crabs support a valuable commercial fishery in the Gulf of Mexico. Most states require the release of undersized and ovigerous blue crabs, yet mortality of these discarded crabs is an understudied component of total mortality. The first objective of this project was to quantify discard mortality of non-target crabs using bycatch surveys across the Lake Pontchartrain–Mississippi Sound coastal system. Ovigerous crabs were most common at high salinities and temperatures, whereas undersized crab presence was inversely correlated with soak time, temperature, and the number of crabs per trap, and also varied among geographic locations. A reflex action mortality prediction assessment …

Public Pool Usage As Adaptation Against Urban Heat, Stefan Borsky, Eric Fesselmeyer

Research Collection College of Integrative Studies

This paper examines the relationship between urban heat and outdoor public pool usage. Using attendance data from all 53 outdoor public pools in New York City, we analyze nonlinear effects of heat on pool usage across socioeconomic contexts. Pool attendance rises sharply with heat, especially in low-income neighborhoods where alternative coping options are likely limited. We also find that public pools reduce heat-related emergency medical service calls. Our findings highlight the need for equitable investment in blue infrastructure to enhance urban climate resilience and demonstrate how this type of adaptive infrastructure can play a critical role in managing urban heat.

At The Intersection Of Science And Sustainability: A Qualitative Study Of Food Scientists' Personal And Professional Perspectives, Srushti Parikh

Theses, Dissertations and Culminating Projects

Sustainable food systems require not only technological innovation but a more profound understanding of the professionals involved in the field. Even though the topic of sustainability is currently gaining importance throughout the food industry, the real expertise of food scientists is under-researched. PURPOSE: The purpose of this study is to explore food scientists' perspectives on sustainability, how these perceptions influence the way they pursue their careers, and how they view their impact in the larger sustainability agenda of the food industry. METHODS AND MATERIALS: This study captured detailed insights of 22 food scientists’ perspectives through qualitative methods. Food scientists in …

Conservation Agriculture Effects On Greenhouse Gas Emissions From Cotton, Soybean, And Corn In Southeast Arkansas, Jonathan Benjamin Brye

Graduate Theses and Dissertations

The slow degradation of natural resources has resulted in the focus of agriculture shifting towards conservation practices, such as reduced/no-tillage, cover crops (CC), and organic amendments (i.e., biochar), that conserve and improve natural resource quality. The objectives of this thesis were to i) quantify the impacts of biochar rate (i.e., 0, 2000, and 4000 kg ha-1) and ii) the combination of CC and tillage practice on carbon dioxide (CO¬2), methane (CH4), and nitrous oxide (N2O) fluxes, growing-season-long emissions, global warming potential (GWP), soil properties, and plant response from a minimally tilled cotton (Gossypium hirsutum)-corn (Zea mays) rotation and a soybean …