Digital Commons Network^™

Fine-Scale Mangrove Species Classification Based On Uav Multispectral And Hyperspectral Remote Sensing Using Machine Learning, Yuanzheng Yang, Zhouju Meng, Jiaxing Zu, Wenhua Cai, Jiali Wang, Hongxin Su, Jian Yang

Earth and Environmental Sciences Faculty Publications

Mangrove ecosystems play an irreplaceable role in coastal environments by providing essential ecosystem services. Diverse mangrove species have different functions due to their morpho- logical and physiological characteristics. A precise spatial distribution map of mangrove species is therefore crucial for biodiversity maintenance and environmental conservation of coastal ecosystems. Traditional satellite data are limited in fine-scale mangrove species classification due to low spatial resolution and less spectral information. This study employed unmanned aerial vehicle (UAV) technology to acquire high-resolution multispectral and hyperspectral mangrove forest imagery in Guangxi, China. We leveraged advanced algorithms, including RFE-RF for feature selection and machine learning models …

Land-Use Change As A Major Driver For Mid-20th-Century Flood Intensity Reduction In The Southeastern Us, Zhixiong Shen, Nicholas Conway, Shaowu Bao, Samuel Muñoz, Andreas Lang

Marine Science

Land-use changes affect hydrologic processes, but their impact on flooding remains obscure amid increasingly heavy precipitation. Instrumental records are short relative to land-use change history and inadequate for flood attribution studies. Here we integrate a high-resolution paleodischarge record spanning the past ∼200 years from the largest basin in the Southeastern United States with instrumental data and hydrological modeling. We find that the 100 yr flood magnitude for large regional rivers exhibits 50%–75% reductions in the mid-20th century. We attribute at least 50% of the reductions to a regional shift from widespread agricultural land to conservation and reforestation and the rest …

Coal Creek Carbon Capture, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about Coal Creek Carbon Capture project, a CarbonSAFE initiative. The Coal Creek Carbon Capture project is investigating the feasibility of developing safe, permanent geologic storage of CO₂ captured from Coal Creek Station.

Preguntas Más Frecuentes De Perforación, Universidad De Dakota Del Norte. Centro De Investigación De Energía Y Ambiental

EERC Brochures and Fact Sheets

Hoja informativa acerca de la investigación geológica de la perforación. Muestras de roca cilíndricas, llamadas núcleos de roca, y datos geológicos serán adquiridos en un pozo exploratorio perforado en el Condado McKenzie, Dakota del Norte

Transferred Benefits In Inter-Community Beach Nourishment: A Field Study On Efficiency, Owen Thomas

Theses, Dissertations and Culminating Projects

To combat the effects of relative sea level rise and the natural erosional processes affecting the sandy, diffusive beaches of New Jersey, most communities utilize beach nourishment to stabilize their beaches. Beach nourishment, the practice of artificially widening the beach berm with sand from other areas, not only stabilizes beaches but also protects oceanfront homes from storm surges, while adding recreational space and tourism value. These benefits are reflected in increased property values, most notably in oceanfront properties. The diffusive nature of these beaches, however, means that individual nourishment events are inherently shared with neighboring communities as sand is readily …

Onset Of Antarctic Glaciation At The Eocene-Oligocene Transition In The Weddell Sea And Its Impact On Ocean Circulation, Victoria Hojnacki

Theses, Dissertations and Culminating Projects

The Eocene – Oligocene Transition (EOT) (34 Ma) represents a greenhouse to icehouse climate transition that is marked by the appearance of permanent ice sheets in Antarctica. Studying this period of climate change allows us to understand how different Earth systems reacted under changing atmospheric CO₂ conditions. Though the timing of the development of the East Antarctic Ice Sheet is well supported, the development of the West Antarctic Ice Sheet is still up for debate. Ocean Drilling Program Site 696 is the only paleoarchive of the EOT in the Weddell Sea region and offers an opportunity to better constrain the …

The Roughrider Carbon Storage Hub, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet regarding the Roughrider Carbon Storage Hub, a CarbonSAFE project. The Roughrider Carbon Storage Hub project is investigating the feasibility of safe, permanent storage of CO₂ in McKenzie County, North Dakota.

Palynostratigraphy And Bayesian Age Stratigraphic Model Of New Ca-Id-Tims Zircon Ages From The Walloon Coal Measures, Surat Basin, Australia, K. Sobczak, J. Cooling, T. Crossingham, H. G. Holl, M. Reilly, J. Esterle, J. L. Crowley, C. Hannaford, M. T. Mohr, Z. Hamerli, S. Hurter

Geosciences Faculty Publications and Presentations

The Surat Basin hosts significant coal and coal seam gas resources. New high-precision CA-TIMS U/Pb zircon ages from tuffs and Bayesian age stratigraphic models are combined with palynology from fine-grained sedimentary rocks and zircon trace elements to provide further chronostratigraphic and biostratigraphic constrains on the Walloon Coal Measures in the eastern margin of the Surat Basin and infer the palaeoenvironment and tectonic setting. The tuff ages range from 165.88 ± 0.11 Ma to 158.84 ± 0.05 Ma, with those from the stratigraphically lower Taroom Coal Measures ranging from 165.88 ± 0.11 to 163.05 ± 0.08 Ma and Juandah Coal Measures …

Evaluation Of Future Sea-Level Impacts Using A Sharp Interface Saltwater Intrusion Model, Caroline Hiott

All Theses

Saltwater intrusion is a growing problem that is being exacerbated by climate change. Saltwater intrusion is the process by which saltwater moves towards freshwater supplies driven by saltwater’s greater density compared to freshwater. Saltwater intrusion can contribute to the salinization of freshwater resources, degradation of underground storage tanks, communication systems, and pipelines, as well as lead to groundwater flooding (Ketabchi et al., 2016). Numerical modeling can be used to simulate saltwater intrusion along coastal areas. One of the more computationally efficient modeling tools is the sharp interface approach, SWI2, that is a part of the MODFLOW 2005 suite (Werner et …

Diatom-Inferred Hydroclimate Variability In Marl Lake, Wi Over The Past ~2050 Years, Christian E. Sizemore

All-Inclusive List of Electronic Theses and Dissertations

Hydroclimate variability in the Midwest has increased over the past few decades, as as evidenced by increases in average precipitation and frequency of extreme hydroclimate events. Understanding natural climate variability in this region will help communities in the Midwest to better prepare and mitigate the risks associated with extreme hydroclimate variability in the future. Natural lakes in the Midwest are often effective archives of hydroclimate; many have been shown to respond directly to changes in climate both locally and regionally. We extracted a 4.5-meter sediment core, representing approximately 2050 years of sediment accumulation, from the deepest part of Marl Lake …

Rock Wall Fracturing As A Potential Control On River Valley Width In The Buffalo National River, Arkansas, Kindle Hon

Graduate Theses and Dissertations

Quantifying bedrock properties that control the persistence of fallen rock material (talus) along bedrock walls bounding river valleys may be a key factor in understanding what controls the rate at which these river valleys widen. My work is a component of a collaborative research project focused on the overarching hypothesis that the persistence vs. erodibility of talus that buffers river valley walls can be a first-order control on valley widening rates. I hypothesize that the primary control for creating erodible or persistent talus is the fracture spacing of bedrock valley walls as it sets the maximum block size of collapsed …

Environments And Controls Of Erosional Bedforms In Soluble Channels, Ethan W. Oleson

Graduate Theses and Dissertations

Erosional bedforms, such as scallops, preserve valuable information on the paleohydrologic conditions forming soluble channels in karst systems. While these bedforms are commonly used to interpret past conditions, questions about their formation remain. Mathematical models of speleogenesis in turbulent flow predict that the conditions for forming scallops do not occur in natural carbonate systems. However, scallops are readily found in caves throughout the world. This conundrum has several possible resolutions, but each lacks field-based observations. We present a field-based study of the environments and controls of scallops in gypsum, limestone, and dolostone caves. Our results are based on field observation, …

Cover-Crop Effects On Near-Surface Soil Properties Over Time In The Lower Mississippi River Valley, Cooper Fanning

Graduate Theses and Dissertations

Human population growth and climate change are present stressors that continue to put pressure on current agricultural production systems, where typical row-crop agricultural practices can negatively impact soil health. Extensive use of cover crops (CC) to increase soil health remains widely unrealized. Soil health in Arkansas is a major concern for sustaining agricultural output, therefore research into CC implementation across Arkansas to maintain or improve soil health is needed. The objective of this study was to evaluate the effects of CC (i.e., with and without CC) across various physical, hydraulic, biological, and chemical soil indicators in the Lower Mississippi River …

Struvite Effects On Greenhouse Gas Emissions From Flood- And Furrow-Irrigated Rice In The Greenhouse, Chandler Arel

Graduate Theses and Dissertations

Over time, as the influences of climate-change and declining, mineable, global phosphorus (P) reserves begin to impact agricultural production systems, alternative fertilizer sources and management practices, such as struvite (MgNH₄PO₄ · 6H₂O) and furrow-irrigation, will be necessary to accommodate nutrient and water demands. The precipitation and use of struvite as a fertilizer-P source could reduce environmental damages caused by nutrient-rich wastewater streams, supplement domestic P supply, and improve the sustainability of flood-, and furrow-irrigated rice production by reducing greenhouse gas emissions. The study of struvite from both chemical and electrochemical precipitation processes is well documented, …

Controls On The Development Of Hummocky Topography On Debris-Covered Glaciers, Ryan M. Strickland

Graduate Theses and Dissertations

Rock debris covers many glaciers in Earth’s highest mountains and the debris impacts glacier response to changes in climate. Interactions between debris, drainage, glacier dynamics, and climate produce contrasts in melt rates that cause debris-covered glaciers to develop complex, hummocky topography. Contrasts in melt rate produce thousands of hills–hummocks–and depressions. Ponds and ice cliffs often form in the depressions. Although ponds and ice cliffs occupy only a small fraction of the surface, they account for nearly half of glacier melt. Understanding the processes that control the development of hummocky topography is key to predicting the evolution of debris-covered glaciers. In …

El Centro De Almacenamiento De Carbono Roughrider, Universidad De Dakota Del Norte. Centro De Investigación De Energía Y Ambiental

EERC Brochures and Fact Sheets

Hojas informativas acerca del Centro de Almacenamiento de Carbono Roughrider, un Proyecto de CarbonSAFE. El Proyecto del Centro de Almacenamiento de Carbono Roughrider está investigando la viabilidad para el almacenamiento Seguro y permanente de CO₂ en el condado McKenzie, Dakota del Norte.

Drilling Faqs, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about geological research drilling. Cylindrical rock samples, called cores, and geologic data will be collected from an exploratory hole drilled in McKenzie County, North Dakota.

Characterizing Groundwater Flow Across The Barrier Island-High Marsh Interface, Dean Michael Wrobel

Electronic Theses and Dissertations

The freshwater resources of barrier islands are influenced by a variety of hydrogeologic factors, which create unique regions of groundwater composition. Factors including evapotranspiration, geologic constraints, tidal forcing, and meteoric inputs influence subterranean flow creating a groundwater salinity gradient throughout the island-marsh setting which directly influences the spatial distribution of dominant vegetation on the island. Rising sea levels and variation in local climate may alter the hydrologic balance on barrier islands, potentially shifting salinity gradients and ecological baselines on short timescales. The intrusion of saltwater into the barrier island freshwater system could result in the shifting of ecotones and potential …

Exploring Intraplate Seismicity In The Midwest, Alexa Fernández

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Intraplate seismicity represents a notable occurrence within the stable North American Craton. This research explores the potential sources of stresses that could reactivate older faults and influence seismic activity within this region. Among these sources, the enduring impact of the last glacial period is considered, which includes continued glacial isostatic adjustments (GIA). During GIA the lithosphere rebounds due to the retreating ice, and the forebulge caused by far-field flexure in response to the glacial load, collapses. This results in significant faulting, fracturing, and seismic activity associated with the deglaciation phase. The adjustment of the lithosphere manifests as both near surface …

Applying Circuit Theory To Describe Changes In Structural Landscape Connectivity In Response To Wildfire, Christian Ross Nielsen

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

Understanding and conserving ecological connectivity is critical to the preservation of vulnerable landscapes. Circuit theory, in which landscapes are imagined as circuit boards with varying resistances to the flow of current, is being increasingly used to model spatially explicit connectivity of landscapes and to inform land management and conservation decision-making. Utilizing continuous, quantitative estimates of percent cover by five land cover functional groups to create a conductance surface, this study expanded upon an established application of circuit theory that used the open-source software Circuitscape to model species-agnostic, omnidirectional connectivity. This model was automated using Python to create time-series connectivity maps …

Occurrence, Inputs, And Ecological Significance Of Antibiotics And Pharmaceuticals In Western Nebraska Streams, Katelyn F. Glause

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

Few emerging environmental contaminants are as concerning as antibiotics. Human and animal health benefits greatly from the prudent use of antibiotics, yet we give little thought to environmental release of these biologically active compounds. Environmental occurrence of these and other pharmaceutical compounds must be measured in different environmental compartments such as municipal wastewater and in the vicinity of large animal feeding operations to understand potential effects. This study reports the results of a monitoring study in western Nebraska, with a large population of livestock and smaller but more concentrated population of humans, comparing the relative environmental concentrations and loading from …

Analysis Of Drought-Flood Abrupt Alternation Events And Their Impacts In Kenya, Betty Makena

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

Drought-Flood Abrupt Alternation (DFAA) is a compound disaster event that refers to the abrupt shift of extreme drought events to extreme floods resulting in exacerbated impacts on already vulnerable communities and hindering their coping abilities. This study aimed to analyze drought-flood abrupt alternation events and their impacts in Kenya. The first chapter aimed to understand historical drought events in the Greater Horn of Africa and their impacts, while drawing comparisons with the recent 2020-2022 drought period, referred to as the ‘triple dip La Niña’. Datasets used in this study include the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), Normalized …

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, …

Impacts Of Invasive Carp And Their Population Dynamics On Fish Communities In The Missouri River, Joshua F. Kocik

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

Invasive Carp species: Silver Carp Hypophthalmichthys molitrix, Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Black Carp Mylopharyngodon piceus have both potential and realized abilities to negatively impact native species. Specifically, Bighead Carp and Silver Carp as filter feeders have been theorized to be detrimental not only to adult filter-feeding species, but to many fish which rely on plankton and algae in their early-life stages. The impact of Invasive Carp on the overall fish community remains underexplored. The fish communities below Gavins Point Dam (Invasive Carp present) and Fort Randall Dam (Invasive Carp absent) afford the …

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

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

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

Assessing, Restoring, And Centering Social–Ecological Relationships For Advancing Social–Ecological Resilience In The Northern Great Plains Grasslands, Katia Pilar Carranza Bernal

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

The Northern Great Plains grasslands are social-ecological systems that were shaped by evolutionary and Indigenous social-ecological relationships. European colonization disrupted many of these interactions, including the coupling of fire and grazing, and degraded social-ecological resilience, shifting these grasslands to a new state. For those reasons, my research focused on assessing, restoring, and centering evolutionary and Indigenous social-ecological relationships for advancing social-ecological resilience in the Northern Great Plains grasslands. I first performed a study in the Nebraska Sandhillls assessing the potential of patch-burn grazing to support grassland resilience by comparing its effects to those of rotational grazing. Through vegetation and bird …

Sensitivity Of Present And Future Seasonal Precipitation Over Central United States To The Representation Of Rocky Mountain Topography, Ranasinghe Disanayakalage Sherly Shelton Ranathunga

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Precipitation change across the Central United States (USA) is of great interest to the research community. Studies using global climate simulations suggest that the “100^th-Meridian”, which separates the “dry west” from the “moist east” will shift to the east as the climate responds to future emissions pathways. However, these simulations are run at relatively coarse resolutions, which do not accurately represent topography. Here, we perform regional simulations using the Weather Research and Forecasting (WRF) model to explore the sensitivity of present and future precipitation patterns across the central USA to the representation of the Rocky Mountains (RM). We …

Integration Of Matlab And Machine Learning To Accelerate Evaluation Of Biological Activity In Agricultural Soils And Promote Soil Health Improvement Goals, Andrew Stiven Ortiz Balsero

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Traditionally, assessments of soil biological activity have been confined to laboratory settings, creating a disconnect with practical in-field methods. To bridge this gap, cotton fabric degradation has been used to illustrate soil microbial activity under different management practices. While effective, these demonstrations are subjective and labor-intensive.

Researchers have explored using image processing software like ImageJ and Adobe Photoshop to streamline this process. Although these tools accurately quantified fabric degradation under varying soil conditions, the methods remained labor-intensive and complex. Consequently, these methods were still not ideal for on-farm use by agricultural practitioners.

To further address labor and complexity limitations, the …

Staying Fresh: Unconventional Approaches Towards Advancing Energy Sustainability, Water Resources, And Community Resiliency In The Southwestern United States, Judith Hoyt

Open Access Theses & Dissertations

This dissertation addresses critical challenges in urban heat management, sustainable energy resource utilization, and water quality communication through three studies. Study 1 investigates the impact of roof color on urban heat islands in Tucson, Arizona where approximately 70% of roofs display high albedo (i.e., light) colors. Energy consumption simulations conducted indicate that converting dark- to light-colored roofs could save Tucson approximately $1,400,000 annually in energy costs, highlighting the potential of cool roofs for energy savings and improved thermal comfort. Study 2 assesses the sources of lithium in subsurface waters in West Texas and South Central New Mexico. Water chemistry data …

Zebra Limestone From The Gypsum Valley Salt Diapir, Colorado, Rebecca Navarrette

Open Access Theses & Dissertations

Zebra rocks displaying alternating light and dark-colored millimeter to centimeter thick bands of crystals have been found at the Gypsum Valley salt diapir, Colorado in the Paradox Basin where they are associated with gypsic diapiric caprock. Elucidating their origin may provide crucial information about intermittent fluid flow at the margin of salt diapirs and about Zebra rock formation, which often is associated with carbonate-hosted lead-zinc mineralization (Mississippi Valley Type, MVT) and hydrothermal dolomite -hosted hydrocarbon reservoirs.

The Gypsum Valley Zebra rocks consist of calcite, i.e., it is a Zebra limestone. It shows a finely crystalline light banding and coarsely crystalline …