Physical Sciences and Mathematics Commons^™

Innovative Machine Learning, Isotopic, And Hydrogeochemical Techniques For Groundwater Analysis In Arid Landscapes In Egypt’S Eastern Desert, Saad Ahmed Mohallel, Hesham Morgan, Ali Elgendy, Surendra Maharjan, Shahryar Fazli, Wenzhao Li, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Groundwater serves as a lifeline in Egypt’s hyper-arid Eastern Desert, particularly for agricultural and domestic uses. However, a comprehensive understanding of groundwater origin, quality, and recharge dynamics in the region remains limited due to geological complexity, data scarcity, and the high cost of isotopic analysis. This study addresses these challenges by integrating stable isotopes (δ¹⁸O and δ²H), hydrogeochemical parameters, remote sensing, and explainable artificial intelligence (AI) to investigate groundwater dynamics and support sustainable water management strategies. A total of 34 groundwater samples were collected from three key aquifers: the Quaternary alluvium, Nubian Sandstone, and fractured Basement aquifers. Hydrochemical analyses and …

Urbanization Impacts Dissolved Organic Matter Concentration And Quality In A Southeastern United States Watershed, Gwendolyn M. Hopper, Erik M. Smith, Jade Dormoy-Boulanger, Claudia R. Benitez-Nelson

Faculty Publications

Blackwater rivers are named due to their exceptionally high concentrations of chromophoric dissolved organic matter (CDOM). They are the predominant lotic ecosystem in the United States Southeastern Coastal Plain, a region experiencing some of the nation’s highest rates of development. This study assessed variability in DOM concentration and composition across forested to urbanized blackwater systems in coastal South Carolina, U.S. Dissolved organic carbon and nutrient concentrations as well as absorbance and fluorescence optical properties reveal that urban sites have lower concentrations, elemental ratios, and less complex DOM. In contrast, forested blackwater sites have concentrations an order of magnitude higher, elevated …

Quantifying Dust Nutrient Mobility Through An Alpine Watershed, Jeffrey R. Nielson, Janice Brahney

Watershed Sciences Faculty Publications

Dust has the potential to play a significant role in the nutrient dynamics of alpine watersheds with important ecological implications. However, little is known about how dust nutrients circulate through the environment and which watershed characteristics facilitate dust impacts on water quality. This study explored the contribution of dust-deposited nutrients, focusing on a high-elevation Long Term Ecological Research site, where dust samples have been continuously collected since 2017. We incorporated observed dust nutrient compositions, including fractions of inorganic and organic nitrogen and phosphorus, into a popular hydrological model, the Soil and Water Assessment Tool, and ran simulations for 2019–2021. By …

Supplementary Files For: "Structure Identification For High-Dimensional Data In The Vicinity Of Bear Lake", Ben Shaw, Haley Burger, Brennan Bean, Kevin Moon

Browse all Datasets

This report focuses on seven water quality measurements taken at 43 different depths on the Bear Lake for the months of June - November in the years 2018 - 2023. These measurements create a high-dimensional dataset on which we apply state-of-the-art machine learning (ML) techniques to look for low-dimensional structure in the data. A similar effort was made for weather measurements taken near the lake. Our analysis revealed that water quality measurements tend to cluster (i.e., group together) by year, while weather measurements tend to cluster by time of the year. This suggests that the structure observed in the water …

The Effect Of Zebra Mussels On Minnesota Fish Communities, Benjamin D. Strei

Journal of Earth and Life Science

Zebra mussels Dreissena polymorpha are an aquatic invasive species that has been spreading quickly throughout Minnesota water bodies since 1989. Zebra mussels are known to change certain morphological conditions in lakes such as turbidity, phytoplankton abundance, and aquatic invertebrate populations. However, studies showing impacts of the infestation of zebra mussels on the health of a fish community have been hard to prove due to a lack of repeated surveys and a suite of other confounding variables such as natural and seasonal variability, plant community, and lake morphometry. Therefore, the objective of this study is to determine whether zebra mussels have …

Multi-Scale Analysis Of Karst Aquifer Vulnerability To Climate Change And Contamination Processes, Shishir Sarker

Theses and Dissertations--Earth and Environmental Sciences

Karst aquifers represent some of the world’s most productive yet vulnerable groundwater systems, supplying freshwater to approximately 10% of the global population across 15% of Earth’s ice-free land surface. Their distinctive hydrological characteristics— including rapid recharge, preferential flow paths, and limited natural filtration— create unique vulnerabilities to both climate variability and contamination that pose significant challenges for sustainable water resource management. This dissertation presents a comprehensive multi-scale analysis of karst aquifer vulnerability through three interconnected studies that examine climate change impacts, microbial contamination dynamics, and contaminant transport processes across diverse geographic and hydrogeologic settings.

Chapter two investigates climate change impacts …

Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen

OES Faculty Publications

In coastal urban areas, tidal flooding brings water carrying nutrients and particles back from land to estuarine and coastal waters. A statistical model to predict nutrient loads during tidal flooding events can help estimate nutrient loading from previous and future flooding events and adapt nutrient reduction strategies. We measured concentrations of dissolved inorganic nitrogen and phosphorus in floodwater at seven sentinel sites during 15 tidal flooding events from January 2019 to September 2020. The study area was the Lafayette River watershed in Norfolk, VA, USA, which is prone to tidal flooding and is predicted to experience more frequent and intense …

Mxene-Based Materials For Enhanced Water Quality: Advances In Remediation Strategies, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Mostafa Shafiee, Lobat Tayebi, Ahmad Vaez, Atefeh Najafian, Ehsan Vafa, Sareh Mosleh-Shirazi

Electrical & Computer Engineering Faculty Publications

Two-dimensional MXenes are promising candidates for water treatment because of their large surface area (e.g., exceeding 1000 m²/g for certain structures), high electrical conductivity (e.g., >1000 S/m), hydrophilicity, and chemical stability. Their strong sorption selectivity and effective reduction capacity, exemplified by heavy metal adsorption efficiencies exceeding 95 % in several studies, coupled with facile surface modification, make them suitable for removing diverse contaminants. Applications include the removal of heavy metals (e.g., achieving >90 % removal of Pb(II)), dye removal (e.g., demonstrating >80 % removal of methylene blue), and radioactive waste elimination. Furthermore, 3D MXene architecture exhibit enhanced performance in antibacterial …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

Spectrum Of The Lakes: Using Satellite Remote Sensing To Unveil Water Color In Minnesota's Sentinel Lakes For Water Quality Monitoring, Andrew J. Dooley, Wondwosen M. Seyoum, Catherine M. O'Reilly

Faculty Publications - Geography, Geology, and the Environment

Traditional water quality monitoring methods often face limitations of equipment costs and labor demands, requiring innovative approaches to effectively assess the ecological health of inland lakes across vast areas. This research explores the application of free, publicly available water color chromaticity analysis for midcontinent lakes in Minnesota, USA. We examined water color variations in Minnesota’s Sentinel Lakes using Landsat 8 OLI data to analyze surface reflectance samples collected from the deepest area within each lake during the late summer, corresponding to peak annual insolation and trophic activity. The median dominant visible wavelength was used to characterize water color. Results indicate …

Water Quality And Microplastic Contamination In An Urbanizing City Nakhon Pathom, Thailand, Boonyarak Chuanchit

Graduate Research Theses & Dissertations

Microplastics (MPs) are synthetic polymer particles less than 5 mm in size that originate from both primary manufacturing and the breakdown of larger plastics. Extensive studies have examined their occurrence in other environments, while little is known about their presence and behavior in groundwater, especially in urbanizing regions in Southeast Asia. This study investigates the occurrence and abundance of microplastics within groundwater systems of Nakhon Pathom, an urbanizing province in central Thailand.

Groundwater was collected representing shallow and deep aquifers between May 2023 and May 2025. The analyses included physical-chemical parameters, major ions, heavy metals, and microplastic abundance and composition. …

Sandy Subterranean Estuaries Minimize Groundwater Nitrogen Pollution Impacts On Coastal Waters, Xiaogang Chen, Isaac R. Santos, Jinzhou Du, Bochao Xu, Joseph J. Tamborski, Ding He, Neven Cukrov, Christian J. Sanders, Jianan Liu, Peiyuan Zhu, Yan Zhang, Ling Li

OES Faculty Publications

Widespread anthropogenic activities pollute groundwater that eventually seeps out to the coastal ocean. Here, we resolve nutrient transformations and fluxes in 11 sandy subterranean estuaries (STEs) with contrasting nutrient sources and development trajectories. Coastal groundwater nitrogen pollution stems from sewage discharge and land use change. Anthropogenically derived groundwater nutrient fluxes with high N/P ratios (∼170) accounted for 22%–61% of riverine inputs into China's coastal waters, providing an additional source of nutrients that can fuel coastal eutrophication and algal blooms. Sandy STEs remarkably attenuated ∼84% of nitrogen pollution, minimizing the impact of submarine groundwater discharge (SGD) on coastal water quality. Hence, …

Changes In Climate And Their Implications For Cattle Nutrition And Management, Bashiri Iddy Muzzo, R. Douglas Ramsey, Juan J. Villalba

Wildland Resources Faculty Publications

Climate change is a global challenge that impacts rangeland and pastureland landscapes by inducing shifts in temperature variability, precipitation patterns, and extreme weather events. These changes alter soil and plant conditions, reducing forage availability and chemical composition and leading to nutritional stress in cattle. This stress occurs when animals lack adequate water and feed sources or when these resources are insufficient in quantity, composition, or nutrient balance. Several strategies are essential to address these impacts. Genetic selection, epigenetic biomarkers, and exploration of epigenetic memories present promising avenues for enhancing the resilience of cattle populations and improving adaptation to environmental stresses. …

Evaluating The Effectiveness Of Benguet Pine (Pinus Kesiya) Xylem For Deep Well Water Filtration, Allen Conner C. Hizon, Robert Zachary M. Santos, Juan Jose B. Lacson, Jefferson Danilo G. Villarin, Juan Carlo T. Gumangan

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Even today, many rural and remote communities still do not have access to safe drinking water, which is a basic right of every human. To address this problem, the effectiveness of the Benguet pine tree (Pinus kesiya) xylem as a sustainable water filtration method for well water was investigated. The physical and chemical properties of the filtered and unfiltered deep well water were tested: the total dissolved solids (TDS) and the electrical conductivity using a 5-in-1 electronic water quality tester and the pH level using pH strips. On the other hand, the microbiological metrics, such as heterotrophic plate …

The Relationship Between Salvinia Molesta Infestation And The Microbial Ecology Of Wetlands At Caddo Lake, Tx, Usa, Martin Hadsell

Electronic Theses and Dissertations

Wetlands are known to host many beneficial geochemical processes such as nutrient cycling and carbon sequestration. These processes are primarily driven by the microbial communities within a wetland. The establishment of non-native invasive species within wetlands has the potential to alter the once beneficial functionality of wetland microbial communities due to the sensitivity microbes have towards environmental changes. Because of this, several metagenomic studies have been conducted to assess microbial community response to aquatic plant invasion; however, there haven’t been any studies researching the influence of Salvinia molesta (D.S. Mitch.), commonly known as Giant Salvinia, on microbial communities. The goal …

Leveraging High-Frequency Water Quality Data And Machine Learning For Monitoring Harmful Algal Blooms, Ibrahim Busari

All Dissertations

Freshwater management is one of the most critical resources on the earth due to the plethora of water use and its limited availability. Increased algae proliferation is one of the significant problems of freshwater bodies that is triggered by nutrient enrichment and enabling conditions such as light and warm temperatures. This algal proliferation is toxic to the ecosystem through their biomass and potential toxin production that can cause hypoxic conditions and is often referred to as Harmful Algal Blooms (HABs). Current monitoring approaches include laboratory analysis of water samples to observe algal cells, monitoring of water quality parameters using water …

Extension Education For Real Estate Professionals: Teaching Regulations And Sharing Resources That Protect Water Quality And Property Values, Linda Patterson, Shari Halik, Kristine F. Stepenuck

Journal of Extension

Real estate professionals can be an important source of information for home buyers and sellers about regulations and practices that protect water quality and properties from environmental damage. Lake Champlain Sea Grant (LCSG) Extension identified a deficit in real estate education covering these topics for real estate professionals. Accredited real estate workshops were initially developed by LCSG Extension and Vermont Agency of Natural Resources specialists. The program was later expanded to New York. Six-month follow-up surveys indicated that the majority of participants continued to use knowledge and tools gained in the workshops. Suggestions for replicating this program elsewhere are provided.

Impact Of Grazing Dairy Cattle On Phosphorus Cycling And Water Quality In A High Water Table Pasture, Bruce W. Mathews, L E. Sollenberger, C R. Staples, C B. Mathews, C G. Chambliss

IGC Proceedings (1977-2023)

During 1990 and 1991 Callie bermudagrass (Cynodon dactylon (L.) Pers.) pastures were used to determine the effects of 3 grazing management systems (short-duration rotational, long-duration rotational and continuous stocking) on P cycling and runoff water quality from intensively managed pastures used to raise replacement heifers (Bos taurus). A hay system also was included to compare soil responses under grazing and clipping. Soil P redistribution was not different among grazing systems, but accumulated in the third of the pastures closest to shade and water. Amounts of soil P were lower in the hay system than in the grazed …

Water Quality Of The Napo River Basin: A Comparative Study Of Streams In Polycultures And Oil Palm Monocultures, Eva C. Andersen

Ecuador: Comparative Ecology and Conservation

Oil palm cultivation has grown rapidly in recent years in Ecuador, resulting in significant economic and environmental changes to the country. In the Northeast Ecuadorian Amazon, a hotspot for both petroleum extraction and oil palm production, poor water quality has been a persistent issue for decades. However, knowledge gaps exist regarding to what extent intensive monocultures, such as oil palm, contribute to poor water quality in this region, and how they compare to other forms of agriculture. This investigation compared water quality in streams of the Napo River watershed running through oil palm monocultures and traditional polycultures. Water quality was …

Nitrate Removal By Floating Treatment Wetlands Under Aerated And Unaerated Conditions: Field And Laboratory Results, Jenna Mccoy, Matt Chaffee, Aaron Mittelstet, Tiffany L. Messer, Steve Comfort

Earth and Environmental Sciences Faculty Publications

Urban and storm water retention ponds eventually become eutrophic after years of receiving runoff water. In 2020, a novel biological and chemical treatment was initiated to remove accumulated nutrients from an urban retention pond that had severe algae and weed growth. Our approach installed two 6.1 m × 6.1 m floating treatment wetlands (FTWs) and two airlift pumps that contained slow-release lanthanum composites, which facilitated phosphate precipitation. Four years of treatment (2020–2023) resulted in median nitrate-N concentrations decreasing from 23 μg L−1 in 2020 to 1.3 μg L−1 in 2023, while PO4-P decreased from 42 μg L−1 to 19 μg …

Detection And Analysis Of Solid-Phase Nutrients In Complex Benthic Cyanobacterium Communities, Cassidy Ann Crandell

Theses and Dissertations

Eutrophication is one of the most serious water quality issues affecting aquatic systems in the United States. Densely populated urban areas as well as mining and agriculture are major sources of anthropogenic nutrient loading into lakes and rivers. Excess loading of nutrients like phosphorus (P) into these ecosystems can cause native algal species to be outcompeted by harmful algal bloom (HAB) species. Increases in these HAB events are a growing public health concern as contact with excreted toxins can be harmful for human, aquatic, and land species. Remediation techniques like total maximum daily loads (TMDLs) have been implemented to reduce …

Refining A Residual Dry Matter Technique For Assessing Standing Biomass Estimates In Grazed Mediterranean Ecosystems, J R. Brown, M Cocke, L Steffen

IGC Proceedings (1977-2023)

Because most water quality objectives are set at the watershed level, it is important to determine hydrologic characteristics of land units within watersheds and predict the impact of land uses and treatments on watershed outputs. Rangeland hydrology research indicates that vegetative cover and biomass are reliable indicators of sediment production from uplands, The Residual Dry Matter (RDM) technique (Clawson et al. 1980} is a proven method of assessing standing crop biomass. This technique is easily learned and observer independent. After one training session, observers were able to estimate accurately (R2>0.90) the amount of biomass on the soil surface. RDM …

Remotely Sensed Early Warning Of Algal Blooms In An Eastern Nebraska Reservoir: A Comparison Of Temporal And Spatial Indicators, Mercy Kipenda

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

Cyanobacterial harmful algal blooms (CyanoHABs) detrimentally affect human, animal, and ecosystem health. Remotely sensed early warning systems for cyanoHABs in inland lakes could contribute to more proactive water quality monitoring and help mitigate negative impacts. Advances in freely available remote sensing imagery, with finer spatial, temporal, and spectral resolutions, present new opportunities for the development and comparative analysis of methods to detect sudden deterioration in lake water quality. In this thesis, I compared and tested for temporal and spatial early warning signals of cyanoHABs in field-based and remotely sensed datasets from 2019 to 2023 in Pawnee Lake in southeast Nebraska, …

The Influence Of Recycled Water On Microbial Source Tracking Techniques That Aim To Identify Untreated Sewage In Surface Waters, Aldo E. Lobos

USF Tampa Graduate Theses and Dissertations

Fecal pollution in recreational waters can introduce pathogens that cause increased human health risk, where exposure can occur during recreational activities such as swimming, diving, surfing, and fishing. Furthermore, human fecal pollution (i.e., sewage) can introduce nutrients and other harmful chemicals that may negatively affect the environment and aquatic species. Generally, sewage is considered the highest risk to human health compared to animal fecal pollution because it typically contains a high diversity of pathogens (including human specific viruses), antibiotic resistant bacteria and genes associated with antibiotic resistance. However, pathogens are difficult to detect due to their low concentrations in the …

Nitrogen Leaching From Dairy Pastures In The Northeast United States, W L. Stout, G F. Elwinger, S L. Fales, L D. Muller, R R. Schnabel, W E. Priddy

IGC Proceedings (1977-2023)

While intensive grazing has the potential to increase dairy farm profitability in the Northeast United States, the uneven recycling of N through feces and urine can increase NO3 - leaching. We measured NO3 - leaching loss from urine and feces beneath N-fertilized orchardgrass using 60 cm diameter by 90 cm deep drainage lysimeters. Mean NO3-N levels in leachate beneath these areas were 3.8, 6.5, 93.5, 110 and 139 mg l-1 for the control, feces, and spring, summer and fall applied urine. Extrapolation of the leaching data over a grazed landscape indicates that a grazing intensity for a 180-day grazing season …

Rock Glaciers In Utah, Scott Hotaling, Kendall Becker, Matthew Morriss

All Current Publications

Utah’s primary water supply––winter snowpack––is in decline due to climate warming coupled with more precipitation falling as rain instead of snow. As snowpack dwindles, other sources of cold stream water, such as rock glaciers, will become more important. Rock glaciers contain significant volumes of internal ice covered by debris. This internal ice provides cold meltwater to mountain streams, sustaining flows in summer and supporting biodiversity. Rock glaciers are common in Utah’s mountains and are projected to be more stable under climate change than Utah’s snowpack. Thus, rock glaciers are likely to persist in their current form even as snowpack volumes …

Surface Water Quality Assessment Of Mingo Creek County Park: The Impacts Of Extractive Industries, Mikayla J. Bayto

Electronic Theses and Dissertations

Historical and current extraction operations and infrastructure, including natural gas pipelines, conventional and unconventional oil and natural gas drilling, longwall coal mining, and strip coal mining, occur throughout the Mingo Creek watershed of Washington County, Pennsylvania, including Mingo Creek County Park. Mingo Creek and several associated tributaries flow through Mingo Creek County Park, eventually discharging into the Monongahela River. An independent water quality study was conducted from June 2020 through July 2023 in Mingo Creek County Park to determine if historical and current extraction activities impact Mingo Creek and its associated tributaries. Weekly sampling of Mingo Creek and associated tributaries …

Water Justice And Equity: The Disproportionate Effects Of Pollution On Black, Indigenous, And Other Communities Of Color, Rae Cade

Theses, Dissertations and Culminating Projects

Access to clean drinking water is a basic human right, regardless of an individual’s background. Yet, discriminatory practices in the United States have disproportionately burdened Black, Indigenous, and other people of color (BIPOC) with contaminated sources of water. Understanding how and why water is disproportionately contaminated in areas with increased diversity, and identifying and targeting areas of environmental injustice, are essential steps for ensuring future water equity. Here, I examine the drivers of inequitable access to clean drinking water within the northeastern United States. In chapter one, I look at the historical drivers of land inequity within the United States. …

Impacts Of Lake Elevation Decline On Tui Chub, A Critical Forage Species For Lahontan Cutthroat Trout In Pyramid Lake, Nevada, Usa, Sarah Barnes

All Graduate Theses and Dissertations, Fall 2023 to Present

Lake level decline affects lakes worldwide, changing the availability and character of nearshore habitat used by fish to spawn, and increasing total dissolved solids (TDS), similar to salinity, a factor that negatively impacts fish health. Lake level decline can affect different lakes in different ways, but typically when lake level declines significantly, there is less nearshore habitat overall, and what nearshore habitat remains has less diverse habitat for fish. We investigated whether both impacts of lake level decline may be causing declines of Tui Chub Siphateles bicolor, a large minnow native to Pyramid Lake that spawns in nearshore habitat. …

General Hydrogeochemical Characterization Of Groundwater In Coastal Aquifers Of Kilwa Kisiwani Oceanic Island, South East Tanzania, Simon R Melchioly

Tanzania Journal of Engineering and Technology (TJET)

The main objective of this study was to determine the hydrogeochemical processes controlling the groundwater chemistry on the Island and assess its suitability for human consumption and irrigation. The methodology used in the study include hydrogeological assessment of the study area and laboratory analysis for general physico-chemical parameters of groundwater. Other parameters such as Soluble sodium percentage (SSP) or % Na+, Sodium Adsorption Ratio (SAR), Magnesium adsorption ratio (MAR), Residual sodium carbonate (RSC), hydrochemical facies classification, and Water Quality Index (WQI) were calculated using empirical formulae. The effects of salinization of groundwater were classified using the chloride-Bicarbonate (Cl/HCO3) and the …