Environmental Sciences Commons^™

Beyond Emergency: Charting Pathways To Sustainable Development In Fragile And Conflict-Affected Settings: A Case Study Of Yemen, Sharif Abdurabu Salem Farid Alsahbool

Theses and Dissertations

For nearly a decade, Yemen's eastern governorates of Hadramawt, Shabwah, and Al‑Mahrah have been relatively stable, yet the international aid system has kept delivering short‑term humanitarian relief like food baskets and water trucking instead of shifting to sustainable development that could rebuild people's lives, create jobs, fix infrastructure, and strengthen local government. This thesis investigates why this transition has taken so long. Based on 21 interviews with government officials, international NGO staff, and local NGO managers in these three governorates, the study develops a new way of understanding the problem. It introduces three ideas: the 'emergency mentality', which is a …

Assessment Of Local Ecological Knowledge, Oyster Predation, And Habitat Function To Improve Management Of Nearshore Habitats, Cynthia Evelyn Marie Lupton

Theses and Dissertations

Coastal ecosystems along the northern Gulf of Mexico are ecologically and economically vital yet increasingly threatened by environmental change, habitat degradation, and knowledge gaps that complicate restoration and management efforts. This dissertation integrates social and ecological approaches to improve understanding of predator dynamics, stakeholder perceptions, and habitat function related to nearshore habitats. Thereby, providing information that can inform adaptive management and restoration in the region through addressing three overarching objectives: 1) evaluate stakeholder perceptions of oyster (Crassostrea virginica) predation and management practices; 2) quantify environmental and habitat factors influencing oyster drill (Stramonita haemastoma complex) abundance; and, 3) assess the influence …

Assessing Water Quality And Nitrogen Dynamics In Bahia Grande, Texas Using Field And Remote Sensing Data, Sk Taufiqul Islam

Theses and Dissertations

An 8,220-acre estuary in South Texas, Bahia Grande has recently been restored from a disconnected hypersaline basin to a tidal estuary. A spatially explicit water quality index (WQI) was developed and in situ physicochemical data coupled with remote sensing data from Sentinel-2 were used to determine ecological integrity. A WQI from 29.45-53.20 yielded a spatial distribution of water quality that displayed a non-linear spatial trend throughout the estuary. Water quality close to the Brownsville Ship Channel inlet yielded values of 'Moderate/Stressed' water quality (> 50). These areas represent local zones of disturbance where ammonium concentrations were more than 11 µmol/L. …

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 …

Metal-Free Nitrogen-Enriched Graphitic Carbon Nitride Architectures For Advanced Supercapacitor Energy Storage: Design, Synthesis, And Electrochemical Performance Optimization, Loujain Gamal Mohamed

Theses and Dissertations

Abstract

This thesis addresses the urgent global requirement for efficient energy storage materials by developing and characterizing advanced graphitic carbon nitride (g-C3N4)-based electrode materials for supercapacitors. A facile, low-cost thermal polymerization method produces 2D nitrogen-rich GCN nanosheets exhibiting excellent electrochemical stability and wide voltage windows, enabling symmetric devices with 19.33 Wh/kg energy density and remarkable cycling stability over 21,000 cycles. To overcome intrinsic limitations of pristine GCN, a 3D/2D metal free composite with bio-derived carbon (Bio-Cx) is synthesized, delivering high capacitance, wide potential windows, and ultrahigh energy density of 53.72 Wh/kg in asymmetric configurations paired with mesoporous nitrogen-doped carbon (MPNDC). …

Characterizing A Low-Gradient Stream In Central Illinois As Gaining Or Losing And Observing Seasonal Changes In This Behavior, Eric Timothy Brunner

Theses and Dissertations

While the seasonal behaviors of low-gradient streams have been studied, the behavior of surface water and groundwater interactions within low-gradient streams in glaciated terrain is not fully understood. A third order, low-gradient glacial stream with a saturated riparian buffer in central Illinois was studied to determine the direction of flow between the surface water and groundwater. The goals of this study were to determine 1) whether the stream was gaining or losing water, and 2) whether the gaining or losing nature of the stream-aquifer system changes seasonally. At both an upgradient and downgradient location, two wells were installed: one in …

An Integrated Data-Driven Framework For Arctic Shipping: Analyzing Vessel Speed, Environmental And Ecological Factors Through Innovative Statistical Spatio-Temporal Methods, Inverse Optimization And Machine Learning, Mauli Pant

Theses and Dissertations

This dissertation develops an integrated data-driven framework to analyze vessel navigation and ecological risk in the United States Arctic from 2010 to 2019. As environmental change and maritime activity increase in the region, understanding how vessels respond to dynamic conditions and how those responses interact with marine ecosystems has become increasingly important. A central theme of this dissertation is the treatment of vessel speed as both an observed outcome and a decision variable reflecting trade- offs among operational, environmental, and ecological factors. The first chapter develops a predictive framework for vessel speed over ground (SOG) using Gaussian Process Boosting (GPBoost), …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Environmental Monitoring In Shallow Lakes: Public Health Threats In Urban Waters, Kyleigh E. Johnson

Theses and Dissertations

Lakes are an integral part of urban and suburban communities, providing ecological, recreational, and public health benefits. Many of these lakes are located in densely populated areas and are subject to urban influences on water quality. Algal toxins and Escherichia coli are two common recreational concerns. Algal toxins come from harmful algal blooms that are influenced by nutrient availability and temperature, while bacteria are often introduced through run-off and animal waste. Sampling every 3-4 weeks from May-October 2025 allowed for the assessment of seasonal patterns and site-specific differences across nine lakes in the Richmond area. The highest bacterial concentrations appeared …

The Effects Of Overwash On Barrier Island Evolution And Building A Barrier Island Measure Of Resistance, Beth Thomas

Theses and Dissertations

Barrier islands are critical for coastal communities, as they serve as a natural buffer against storm surge, waves, and the effects of rising sea levels, protecting life and property. These islands continuously evolve due to both normal and severe environmental conditions; global warming makes it increasingly difficult to predict the evolution of these islands due to increases in storm frequency and intensity. We present a cellular model of barrier island evolution consisting of biotic and abiotic processes including the effects of vegetation, wind, ocean currents, and gravity. The model is used to predict the future evolution of barrier islands off …

Machine Learning-Based Spatio-Temporal Modeling Of Climate Dynamics And Desertification In The Sahara–Sahel Region, Stephen M. Tivenan

Theses and Dissertations

Arid climate classifications are threshold-dependent and easily interpretable mappings that are widely used in ecological, agricultural, and climate-related studies. These classifications inform scientific understanding, support policy and land management decisions, and provide an intuitive summary of environmental conditions. Despite their usefulness, traditional arid climate classifications often fail to quantify uncertainty, incorporate spatial context, or account for complex relationships among relevant environmental variables. Existing approaches to uncertainty assessment have largely relied on comparing classifications across multiple datasets or alternative formulas, but these methods generally overlook important spatial dependence and latent structure in the data.

This dissertation develops three machine learning-based statistical …

High-Resolution Mapping Of Soil Moisture Variation Using Uas Thermal And Multispectral Imagery, Jackline Amma Timah

Theses and Dissertations

In agricultural landscapes, soil moisture regulates hydrologic partitioning, nutrient transport and water quality, land-atmosphere energy exchange that shapes local climate, and ecosystem resilience. However, traditional monitoring approaches, such as in-situ sensors and satellite imagery, often lack the spatial resolution required to capture fine-scale soil moisture variability. This study evaluated whether unmanned aerial system (UAS)-derived thermal, multispectral, and terrain variables can capture fine-scale spatial variability in volumetric water content (VWC) within an SRB in central Illinois.

High-resolution imagery was collected and paired with 50 field-measured VWC observations. Land surface temperature (LST), vegetation indices (NDVI and NDRE), spectral bands, and slope were …

Assessing Water Quality And Algae In Wetland Reserve Easements In The Alluvial Valleys Of Mississippi And Louisiana, Avery June Wissmueller

Theses and Dissertations

Wetlands in agricultural landscapes play a critical role in improving water quality by retaining and transforming nutrients and pollutants. In the Mississippi Alluvial Valley (MAV), widespread conversion of bottomland hardwood forests to row-crop agriculture has diminished this natural function. The Wetland Reserve Easement (WRE) program restores wetlands on marginal farmland to recover ecosystem services. In this study, I evaluated water quality and algal productivity in WREs compared to natural reference wetlands and crop sites. Restored wetlands showed improved water quality compared to crop sites and were often comparable to or intermediate between reference wetlands. Seasonal variation and hydrologic differences shaped …

Collective Agency And Community Resilience Among Farmworkers In The Lower Rio Grande Valley, Angel Velazquez

Theses and Dissertations

This research assesses how farmworkers in the Lower Rio Grande Valley of Texas use everyday practices to build resilience and adapt to changes in their lives. I apply two interconnected theories, White’s (2017, 2019) framework of collective agency and community resilience and Castro and Sen’s (2022) framework of everyday adaptation actions, to study these practices. I conducted 19 semi-structured interviews with Latino farmworkers and professionals who work with local farmworker organizations in the Rio Grande Valley (RGV) of Texas. Interview transcripts were analyzed to determine if and how Latino farmworkers in the RGV can work towards community resilience and implement …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Seagrass Preference Among Pinfish In The Lower Laguna Madre, Nathaniel Garza

Theses and Dissertations

Pinfish (Lagodon rhomboides) is a common estuarine fish species found from Massachusetts to the Yucatan, Mexico. As juveniles, pinfish spend a significant portion of their life in coastal seagrasses which provide both shelter from predators and food. Along the Texas coast, there are three major species of seagrass- turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii) that differ in structural complexity. The goal of this study was to determine if pinfish associate more with one seagrass species than the others. A year-long field study was completed using twelve sample sites in the Lower Laguna Madre, …

Interactive Effects Of Nutrient Loading And Hyposalinityon The Physiological Responses Of The Red Macroalga Gracilaria Tikvahiae, Donavuan Vincent Salazar

Theses and Dissertations

Coastal macroalgae face anthropogenic stressors such as nutrient enrichment from nitrogen fertilizers and reduced salinity linked to flooding. The physiological impacts of these combined stressors remain unclear. This study examined interactive effects of nitrogen loading and hyposalinity on Gracilaria tikvahiae through a 9‑day laboratory experiment. Samples experienced declining salinity (35–0 ppt) with nitrate or ammonia enrichment (120 µmol/L). Measurements included primary production, respiration, biomass, nitrate uptake, and chlorophyll‑a. Hyposalinity significantly reduced physiological performance, with gross primary production declining over 100%, chlorophyll‑a content 25–45% lower, biomass loss, and reduced nitrogen uptake. Nitrogen enrichment failed to mitigate the adverse impacts under hyposaline …

Population Structure Of Red Drum (Sciaenops Ocellatus (Linnaeus, 1766)) In Two Systems In The Northwestern Gulf Of Mexico, Sandra Antonia Leal

Theses and Dissertations

Red drum (Sciaenops ocellatus) are an economically significant species of fish inhabiting the Gulf of Mexico. There are limited studies assessing S. ocellatus population structure focused on the southern coast of Texas. A total of 1,008 fish were collected over one year on a quarterly basis at South Bay (SB) and Holly Beach (HB) in the Lower Laguna Madre (LLM) of Texas to assess population structure. Juvenile S. ocellatus utilize the water systems of the LLM as a nursery ground and were more abundant at SB (n = 718) than HB (n = 290). The most abundant age classes were …

Modern Water And Sediment Transport Patterns In Alluvial Ridge Basins Of The Rio Grande Delta, South Texas, Usa, Waqid Nabi

Theses and Dissertations

Alluvial ridge (AR) basins are shallow, marine-influenced depressions within river deltas, yet their flow and sediment dynamics remain poorly understood. This study examines hydrodynamics and sediment transport patterns in the Bahia Grande Complex, which are AR basins of the Rio Grande Delta, using tilt current meters, water-level and turbidity loggers, and suspended and bed-sediment sampling. The AR basins function as wind-dominated, microtidal environments, where pre-existing basin geometry and hydrodynamic forcings control water flow and sediment distribution patterns. Seasonal wind patterns and storms modulate water levels and flow connectivity. Substrate patterns reflect frequent resuspension in the shallow northern basin, maintaining coarse …

Benthic Infaunal Responses To Shoreline Restoration, Jessica Lauren Cline

Theses and Dissertations

In the age of increasing urban coastal sprawl, natural shorelines are being replaced by hard armoring structures, which result in the loss of valuable ecosystem services. Hybrid living shorelines, areas that include limited and less intensive armoring strategies paired with the integration of plants and other natural materials, present an opportunity to marry the need for more aggressive stabilization with the continued preservation of ecosystem functions and biological communities. This project uses benthic infauna to evaluate the success of a living shoreline installation in Palm Bay, Florida. The deployment features experimental treatments of breakwaters and red mangroves to explore how …

Assessing Inclusion Within Naaee Affiliate Ee Associations And Where To Go From Here, Connor Chilton

Theses and Dissertations

Environmental Education (EE) has a history that has been typically defined by traditionally dominant identities (White, male, able-bodied, etc.). The North American Association for Environmental Education (NAAEE) offers a unique position as frontrunners for the field of EE and have the duty to provide an inclusive-minded education for and about the environments throughout the world. Through NAAEE’s affiliate network within the United States, this paper details a glimpse into the work towards inclusion by surveying its leadership position holders about the broad subject and several interconnections of inclusion. Upon completion of the survey, participants who opted to participate in a …

Determining The Toxic Threshold And Other Use Characteristics For Industrial Hemp Seed Oil Used For Wood Product Protection, Daylan M. Barnes

Theses and Dissertations

Plant-based wood treatments have been utilized for many years, with varying success. Oils such as those extracted from linseed (flax), tung, and hemp plants have been used for thousands of years as finishes on wood. These are all drying oils, which dry to a film when exposed to air. Hemp seed oil has a high fatty acid content and can take a long time to dry on wood products but is valued in woodworking for being easy to use, food-safe, and having little to no odor. In this study, cold-pressed hemp seed oil, blended with a soybean carrier oil, is …

The Effect Of An Invasive Species (Lantana Camara) And A Fast-Growing Herb (Acanthus Pubescens) On The Plant And Animal Communities In Kibale National Park, Uganda, Kathleen Bufka

Theses and Dissertations

Fast-growing plant species, like Lantana camara and Acanthus pubescens, could threaten biodiversity in Kibale National Park, Uganda. I surveyed plants and wildlife in areas where these plants were frequently encountered compared to those areas where they are infrequent. I found mixed results based on plant traits and the animals considered. My findings support management efforts on these two species to prevent forest degradation.

Arginine Vasotocin And Corticosterone In Nesting And Non-Nesting Loggerhead Sea Turtles In X’Cacel-X’Cacelito Sanctuary, Krista Blair Reed

Theses and Dissertations

Sea turtles exhibit distinct behaviors before and after egg laying, however, not all individuals successfully oviposit. Some females display disruptions in their typical nesting behavior, returning to the water without laying eggs, which is referred to as a non-nesting emergence (NNE). NNEs can be due to external disturbances on the beach, but why they occur is often unclear. Arginine vasotocin (AVT) is a neuropeptide involved in various physiological processes, including stimulating smooth muscle contraction of the oviduct to facilitate egg deposition in nesting sea turtles. On the other hand, corticosterone is the primary stress hormone in sea turtles and is …

Machine Learning Applications For Evaporation Predictions From Small Reservoirs: Potential Water Savings For Lower Rio Grande Valley, Texas, Syed Muhammad Fahad Abdullah

Theses and Dissertations

Local-scale reservoirs are important to regional water balance, but these are often overlooked. This study presents a robust machine learning (ML) approach leveraging reanalysis datasets to estimate daily evaporation for local-scale reservoirs in semi-arid South Texas. Selected models were trained with daily lake evaporation model (DLEM) estimates and used climatic and reservoir-specific properties as feature input variables. The multi-reservoirs training approach ensured applicable model generalization. Results show promising predictive performance with R² values ranging from 0.55–0.67 (testing) and 0.64–0.78 (validation), NSE values ranged from 0.54 0.67 (testing) and 0.64–0.78 (validation), and RMSE values ranged between 1.52–1.80 mm/day (testing) and 1.22–1.58 …

Transformation With Genes To Improve Lipid Production And Barcoding To Identify Unknown Algal Species, Michelle T. Rada

Theses and Dissertations

With the rising demand for alternative fuels, algal-based biofuels are a promising, sustainable source that meets commercial interest while producing lower greenhouse gas emissions compared to fossil fuels. This thesis explored two studies, evaluating microalgae for their future potential in lipid yield for biofuel production.

The first study involved developing a cost-efficient electroporation protocol that allowed for the genetic transformation of Chlamydomonas reinhardtii using the pChlamy_4 vector, which supports future cloning of genes to enhance lipid production. Parameters affecting DNA uptake and integration into algal genomes were studied: the effect of cell density, the settings of the electroporation device, and …

Electrocatalytic Degradation Of Methylene Blue Using Graphene Oxide, Antimony Oxide, And Graphene Oxide-Supported Antimony Oxide Ink-Based Electrodes, Maria Irene Myers Armas

Theses and Dissertations

This study investigates the electrocatalytic degradation of methylene blue (MB) using copper mesh electrodes coated with graphene oxide (GO), antimony oxide (Sb₂O₃), and their composite (GO/Sb₂O₃). These materials were evaluated across a pH range of 2 to 8 using sodium sulfate as the supporting electrolyte. UV-Vis spectroscopy at 665 nm confirmed dye degradation, with removal efficiencies reaching up to 95% at pH 2. However, degradation decreased at higher pH, with 40 – 60% removal at pH 8, depending on the electrode. Kinetic analyses revealed optimum performance under acidic conditions. GO/Sb₂O₃ electrodes demonstrated the most consistent and effective performance across all …

Assessing The Effect Of Covid-19 On Air Quality For Five Texas Metro Areas Using Daily Air Quality Index Values, Rahul Sahajpal

Theses and Dissertations

Air pollution is one of the biggest health hazards known to humans. The quality of the air that we breath is mainly determined by the level of six major air pollutants, Carbon Monoxide (CO), Nitrogen dioxide (NO₂), Particulate Matter 10 (PM 10), Particulate Matter 2.5 (PM 2.5), Sulfur dioxide (SO₂) and Ozone (O₃). The main source of these air pollutants are fossil fuels (Oil, Coal and Natural gas). Their levels in the air are reported using an Air Quality Index (AQI). Higher AQI values indicate bad air quality and vice versa. In this study …