Digital Commons Network^™

Three-Dimensional Modeling Of Nitrate-N Transport In Vadose Zone: Roles Of Soil Heterogeneity And Groundwater Flux, Simin Akbariyeh, Shannon L. Bartelt-Hunt, Daniel D. Snow, Xu Li, Zhenghong Tang, Yusong Li

Department of Civil and Environmental Engineering: Faculty Publications

Contamination of groundwater from nitrogen fertilizers in agricultural lands is an important environmental and water quality management issue. It is well recognized that in agriculturally intensive areas, fertilizers and pesticides may leach through the vadose zone and eventually reach groundwater. While numerical models are commonly used to simulate fate and transport of agricultural contaminants, few models have considered a controlled field work to investigate the influence of soil heterogeneity and groundwater flow on nitrate-N distribution in both root zone and deep vadose zone.

In this work, a numerical model was developed to simulate nitrate-N transport and transformation beneath a center …

Vegetation Responses To Sagebrush-Reduction Treatments Measured By Satellites, Aaron N. Johnston, Erik A. Beever, Jerod A. Merkle, Geneva Chong

United States Geological Survey: Staff Publications

Time series of vegetative indices derived from satellite imagery constitute tools to measure ecological effects of natural and management-induced disturbances to ecosystems. Over the past century, sagebrush-reduction treatments have been applied widely throughout western North America to increase herbaceous vegetation for livestock and wildlife. We used indices from satellite imagery to 1) quantify effects of prescribed-fire, herbicide, and mechanical treatments on vegetative cover, productivity, and phenology, and 2) describe how vegetation changed over time following these treatments. We hypothesized that treatments would increase herbaceous cover and accordingly shift phenologies towards those typical of grass-dominated systems. We expected prescribed burns would …

Exotic Invasive Pomacea Maculata (Giant Apple Snail) Will Depredate Eggs Of Frog And Toad Species Of The Southeastern Us, Jacoby Carter, Darren Johnson, Sergio Merino

United States Geological Survey: Staff Publications

Pomacea maculata (Giant Apple Snail) is a freshwater snail from South America that is an invasive species on the Gulf of Mexico coastal plain. A sister species has been shown to prey on amphibian eggs in Asia. To test whether the Giant Apple Snail will prey on amphibian eggs, we presented eggs of Lithobates palustris (Pickerel Frog), Lithobates pipiens (Northern Leopard Frog), and Anaxyrus americanus (American Toad) to Giant Apple Snails in a laboratory experiment. Giant Apple Snails ate the eggs of all 3 species.

Evaluating Restored Tidal Freshwater Wetlands, Andrew H. Baldwin, Richard S. Hammerschlag, Donald R. Cahoon

United States Geological Survey: Staff Publications

Tidal freshwater wetlands are recognized as highly productive coastal wetlands that support diverse assemblages of plants and animals and complex biogeochemical cycles (in this book, see Chapter 18 by Whigham et al. and Chapter 19 by Megonigal and Neubauer). Many tidal freshwater wetlands and their associated ecosystem services have been damaged or destroyed by urbanization, agriculture, and other human activities (Baldwin, 2004; Barendregt et al., 2006). Increasing recognition of the value of remaining wetlands and environmental regulations requiring wetland mitigation (i.e., enhancement, creation, or restoration of wetlands to compensate for wetland losses; Kentula, 2000) has driven the restoration of all …

Evaluating The Waterfowl Breeding Population And Habitat Survey For Scaup, Michael L. Schummer, Alan D. Afton, Shannon S. Badzinski, Scott A. Petrie, Glenn H. Olsen, Mark A. Mitchell

United States Geological Survey: Staff Publications

Potential bias in breeding population estimates of certain duck species from the Waterfowl Breeding Population and Habitat Survey (WBPHS) has been a concern for decades. The WBPHS does not differentiate between lesser (Aythya affinis) and greater (A. marila) scaup, but lesser scaup comprise 89% of the combined scaup population and their population estimates are suspected to be biased. We marked female lesser scaup (i.e., marked scaup) in the Mississippi and Atlantic Flyways, Canada and United States, with implantable satellite transmitters to track their spring migration through the traditional and eastern survey areas of the WBPHS, 2005–2010. Our goal was to …

Evaluating The Waterfowl Breeding Population And Habitat Survey For Scaup, Michael L. Schummer, Alan D. Afton, Shannon S. Badzinski, Scott A. Petrie, Glenn H. Olsen, Mark A. Mitchell

United States Geological Survey: Staff Publications

Potential bias in breeding population estimates of certain duck species from the Waterfowl Breeding Population and Habitat Survey (WBPHS) has been a concern for decades. The WBPHS does not differentiate between lesser (Aythya affinis) and greater (A. marila) scaup, but lesser scaup comprise 89% of the combined scaup population and their population estimates are suspected to be biased. We marked female lesser scaup (i.e., marked scaup) in the Mississippi and Atlantic Flyways, Canada and United States, with implantable satellite transmitters to track their spring migration through the traditional and eastern survey areas of the WBPHS, 2005–2010. Our goal was to …

The Role Of Channel Fens In Permafrost Degradation Induced Changes In Peatland Discharge At Scotty Creek, Nt, Lindsay Elena Stone

Theses and Dissertations (Comprehensive)

Permafrost degradation in the peat-rich southern fringe of the discontinuous permafrost zone is producing substantial changes to land cover with concomitant expansion of permafrost-free wetlands (bogs and fens) and shrinkage of forest supported by permafrost peat plateaus. Predicting discharge from headwater basins in this region depends on understanding and numerically representing the interactions between storage and discharge within and between the major land cover types, and how these interactions are changing. To better understand the implications of land cover change on wetland discharge, the hydrological behaviour of a channel fen in the headwaters of Scotty Creek, Northwest Territories, Canada, dominated …

Can Increasing Grass-Fungal Endophyte Symbiotic Diversity Enhance Grassland Ecosystem Functioning?, Mahtaab Bagherzadeh

Theses and Dissertations--Plant and Soil Sciences

The relationship between biodiversity and ecosystem functioning is important in maintaining agroecosystem sustainability. Plant-microbe symbioses, such as exists between the grass tall fescue (Schedonorus arundinaceum) and the asexual fungal endophyte Epichloë coenophiala, can be utilized to enhance agroecosystem functions, such as herbivore resistance. “Novel” E. coenophiala strains that vary in the production of mammal- and insect-toxic compounds have been identified, inserted into tall fescue cultivars, and are planted in pastures globally. Novel fungal endophyte-tall fescue associations may have divergent ecosystem function effects. This study assessed effects of different fescue-endophyte symbiotic combinations on pasture ecosystem function, including aboveground …

Exploring Spatial And Temporal Variability Of Soil And Crop Processes For Irrigation Management, Javier Reyes

Theses and Dissertations--Plant and Soil Sciences

Irrigation needs to be applied to soils in relatively humid regions such as western Kentucky to supply water for crop uptake to optimize and stabilize yields. Characterization of soil and crop variability at the field scale is needed to apply site specific management and to optimize water application. The objective of this work is to propose a characterization and modeling of soil and crop processes to improve irrigation management. Through an analysis of spatial and temporal behavior of soil and crop variables the variability in the field was identified. Integrative analysis of soil, crop, proximal and remote sensing data was …

A Bayesian Hierarchical Approach To Multivariate Nonstationary Hydrologic Frequency Analysis, C. Bracken, K. D. Holman, B. Rajagopalan, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

We present a general Bayesian hierarchical framework for conducting nonstationary frequency analysis of multiple hydrologic variables. In this, annual maxima from each variable are assumed to follow a generalized extreme value (GEV) distribution in which the location parameter is allowed to vary in time. A Gaussian elliptical copula is used to model the joint distribution of all variables. We demonstrate the utility of this framework with a joint frequency analysis model of annual peak snow water equivalent (SWE), annual peak flow, and annual peak reservoir elevation at Taylor Park dam in Colorado, USA. Indices of largescale climate drivers—El Ni~no Southern …

Evolution Of The Modern Baboon (Papio Hamadryas): A Reassessment Of The African Plio-Pleistocene Record, Christopher C. Gilbert, Stephen R. Frost, Kelsey D. Pugh, Monya Anderson, Eric Delson

Publications and Research

Baboons ( Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi , Papio robinsoni and Papio angusticeps. Because of their derived appearance, P. angusticeps and P. robinsoni have sometimes been considered subspecies of P. hamadryas and have been used as biochronological markers for the Plio- Pleistocene hominin sites where they are found.

We reexamined fossil Papio forms from across Africa with an emphasis on their distinguishing features and …

Impacts Of Vegetation Growth On Reach-Scale Flood Hydraulics In A Sand-Bed River And The Implications For Vegetation-Morphology Coevolution, Samuel Box

Graduate Student Theses, Dissertations, & Professional Papers

Vegetation affects river morphology via plant effects on the flow field, sediment transport and deposition, and substrate erodibility. Changes in the flow field caused by above-ground biomass mediate geomorphic response to flooding and habitat suitability for vegetation growth. Using numerical hydraulic models that incorporate drag due to spatially heterogeneous vegetation, I quantify how changes in the antecedent characteristics of woody vegetation in the active channel lead to changes in local bed shear stress, reach-average bed shear stress, and the vegetative component of reach-average total shear stress. Flood hydraulics in turn affect channel morphology and vegetation, providing a feedback mechanism by …

Stream Water And Soil Water Chemistry After The Table Mountain Wildfire, Washington, Usa, Vincent J. Roccanova

All Master's Theses

Analyses of major and trace elements, major ions, and nutrient concentrations were made to investigate how stream water and soil water chemistry changed over 16 months following the Table Mountain wildfire. Sites with different burn severity were also compared. The fire occurred in 2012 in Kittitas County, north of Ellensburg, Washington. Samples were collected at severely burned, moderately burned, and unburned field sites from within and adjacent to the wildfire perimeter. Total nitrogen concentrations increased in the second year after the fire in both the severely and moderately burned sites. In contrast, total phosphorus was variable at all three sites …

Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, Barry Herschy, Sae Jung Chang, Ruth Blake, Aivo Lepland, Heather Abbott-Lyon, Jacqueline Sampson, Zachary Atlas, Terence P. Kee, Matthew A. Pasek

School of Geosciences Faculty and Staff Publications

The element phosphorus (P) is central to ecosystem growth and is proposed to be a limiting nutrient for life. The Archean ocean may have been strongly phosphorus-limited due to the selective binding of phosphate to iron oxyhydroxide. Here we report a new route to solubilizing phosphorus in the ancient oceans: reduction of phosphate to phosphite by iron(II) at low (°C) diagenetic temperatures. Reduction of phosphate to phosphite was likely widespread in the Archean, as the reaction occurs rapidly and is demonstrated from thermochemical modeling, experimental analogs, and detection of phosphite in early Archean rocks. We further demonstrate that the higher …

Hydrogen, Carbon, And Oxygen Isotopes In Prosopis Sp. Trees: A New Climate Proxy For Holocene Paleoclimate In The Atacama Desert, Chile, Elizabeth Joy Olson

Graduate Research Theses & Dissertations

The spatial ubiquity of trees in terrestrial ecosystems worldwide facilitates the use of stable isotope research in tree-rings to address a wide-range of interdisciplinary questions related to climate, ecology, archaeology, and hydrology. This dissertation focuses on the development and application of Prosopis tamarugo tree-ring stable isotope records as a paleoclimate proxy for the Atacama Desert, Chile. Current paleoclimate proxies from this region lack the spatial and temporal resolution to quantify a causal mechanism for observed Holocene hydroclimate variability. P. tamarugo tree-ring isotopes provide a high-resolution proxy that facilitates the reconstruction of hydroclimate variability at a regional scale. In order to …

Photochemical Cycling Of Reactive Oxygen Species In Hydrothermal Systems: Impacts On Biosignature Preservation, Megan A. Mave

Graduate Student Theses, Dissertations, & Professional Papers

Life originated on early Earth, despite harsh, highly reducing conditions. Life may have also emerged on early Mars, when conditions on the two planets were similar (i.e. before atmosphere loss and desiccation). NASA’s 2020 Mars rover mission aims to identify biosignatures (i.e. evidence of life) in early Martian deposits. Potential exploration sites include extinct hydrothermal springs, due to their high habitability and preservation potential. This study aims to better understand biosignature preservation in hydrothermal systems analogous to those on early Mars (i.e. reducing and Fe-rich).

Reactive oxygen species (ROS) are highly reactive molecules formed primarily by photochemical reactions. ROS are …

Assessment Of The Disinfection Capacity And Eco-Toxicological Impact Of Atmospheric Cold Plasma For Treatment Of Food Industry Effluents, Apurva Patange, Daniela Boehm, Michelle Giltrap, Peng Lu, Patrick J. Cullen, Paula Bourke

Articles

Generation of wastewater is one of the main environmental sustainability issues across food sector industries. The constituents of food process effluents are often complex and require high energy and processing for regulatory compliance. Wastewater streams are the subject of microbiological and chemical criteria, and can have a significant eco-toxicological impact on the aquatic life. Thus, innovative treatment approaches are required to mitigate environmental impact in an energy efficient manner. Here, dielectric barrier discharge atmospheric cold plasma (ACP) was evaluated for control of key microbial indicators encountered in food industry effluent. This study also investigated the eco-toxicological impact of cold plasma …

Understanding The Food Water Nexus: Characterizing The Impact Of Climatological Anomalies On Agrosystems, Patrick M. Wurster Jr.

Graduate Student Theses, Dissertations, & Professional Papers

Climate variability at global and regional scales is escalating with increased atmospheric carbon and is expected to magnify the intensity and duration of meteorological extremes, especially droughts. From the many environmental stresses that diminish crop production (e.g., soil salinity, frost, soil erosion) drought is one of the most prevalent. This study focuses on the sensitivity of three key crops produced in the northwestern United States to climatological anomalies, while controlling for attribution using anomalies in price. The study differs from similar studies in that we focus on variability in production which captures both yield (tonnes/ha) and cropping area (ha), as …

Organic Acids And Amino Acids In Serpentinization Related Fluids From The Atlantis Massif, Nicholas Camper

Theses and Dissertations

Serpentinization is a low temperature, low pressure process that occurs when water reacts with ultramafic rocks. Fluids that have interacted with serpentinites have elevated concentrations of hydrogen and reduced carbon species that can fuel chemolithoautotrophy. International Ocean Discovery Program Expedition 357 drilled a series of boreholes into the Atlantis Massif with the goal of investigating how serpentinization impacts carbon cycling and sustains life in the subseafloor. Bottom water samples (CTD), fluids flushed from the boreholes during drilling (Rock Drill), and fluids that were trapped in the liners of the cores (Liner fluids) were collected. The changes and distributions of organic …

Classifying The Woody Vegetation Community Of Wade Ponds In Colleton County, South Carolina, Wade Biltoft

Theses and Dissertations

Wetland habitats are some of the most biodiverse ecosystems in the world, varying in both physical and biological characteristics. Geographically isolated wetlands are particularly important to the landscape due to their role in the hydrological cycle and as local centers for biodiversity. In parts of the coastal plain of South Carolina, there are geographically isolated wetlands found in concentrated groups with distinctive size, shape, and distribution. Despite their unique appearance and distribution, these wetlands have been scarcely researched or investigated. This project seeks to explore the plant communities that are contained within these ponds in order to understand their composition …

Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad

Senior Independent Study Theses

The Campanian Stage of the Upper Cretaceous was established by Henri Coquand in 1857 based on a sequence of richly fossiliferous shallow water carbonates in the Charente and Charente-Maritime departments of southwestern France. One of the most common macrofossils is the gryphaeid oyster Pycnodonte vesicularis (Lamarck, 1806), which often forms extensive shell beds. This bivalve lived primarily on soft marly substrates, forming hard substrate islands. They frequently supported sclerobiont communities comprising encrusters (diverse cheilostome and cyclostome bryozoans, foraminiferans, oysters, bivalves, sabellid and serpulid polychaetes, calcareous sponges), borers (the sponge borings Entobia, the worm borings Maeandropolydora and Caulostrepsis, the barnacle borings …

Using N-Alkane As A Proxy To Reconstruct Paleoenvironment In Thale Noi, Phatthalung Province, Assuma Sainakum

Chulalongkorn University Theses and Dissertations (Chula ETD)

Normal alkane (n-alkane) is the widely used hydrocarbon proxy for the paleoenvironmental study because of their specific characteristic and resistance to microbial degradation. The n-alkanes from the sediment cores TLN-CP5 and TLN-CP7 from Thale Noi, Phatthalung Province, were analyzed and subsequently compared with those derived from the recent plant samples. The plant samples were taken from mangrove forests, i.e. true mangrove, back mangrove, and mangrove associate, based on the previous study on pollen analysis. The n-alkane distributions, the average chain length (ACL), the carbon preference index (CPI) and the proportion of aquatic components (Paq) were further analyzed in order to …

Lithological Classification By Deep Learning Algorithm, Worapop Thongsame

Chulalongkorn University Theses and Dissertations (Chula ETD)

Six machine learning algorithms are used to classify subsurface rocks based on fifteen well logging features from four geothermal wells in the Snake River Plain, Idaho, USA. Two experimental designs, single- and multiple-well tests, are developed to determine the most optimal model and hyperparameters. The single-well test randomly assigns the data in each well into 70% for training set, 10% for validation set, and 20% for test set. The multiple-well test combines data from three wells and splits the data in the fourth well into 70% for training set, 10% for validation set, and 20% for test set. Results show …

Seismic Characteristics Of Paleo-Pockmarks At Great South Basin, New Zealand, Arunee Karaket

Chulalongkorn University Theses and Dissertations (Chula ETD)

Paleo-pockmarks and present-day pockmarks are founded in several varieties both onshore and offshore worldwide. These features can be used as an indicator of fluid flow process which expulses through an unconsolidated sediment within the basin. The Great South Basin, New Zealand is one of the basins that paleo-pockmarks are observed covering the southeast offshore of South Island at around 1.5 s (TWT) depth beneath the surface. This study aims to identify seismic characteristics of paleo-pockmarks in the Great South Basin and predict the possible fluid origins and their mechanism. The numerous paleo-pockmarks are identified and imaged by using 3D seismic …

Qualitative And Quantitative Analysis Of Carbonate Waters In The Peters Mountain Region Of Monroe County, Wv, Emily A. Bausher

Graduate Theses, Dissertations, and Problem Reports (ETD)

Water in Monroe County, WV is used extensively for public and private supply and requires quantification, chemical analysis, and assessment for contamination susceptibility. Over 250 springs were previously identified in the eastern side of Monroe County on or near Peters Mountain; 14 were continuously monitored in this study. Springs were grouped based on geologic and spatial distribution: interbedded clastic-rock springs on the mountain flanks, carbonate springs in the valley, and a thermal spring associated with the St. Clair thrust fault. Clastic and carbonate springs have calcium-magnesium-bicarbonate chemistries, neutral pHs and high alkalinities; the thermal spring has calcium-magnesium-sulfate-carbonate chemistry, low pH, …

Interpreting Mosaics Of Ocean Biogeochemistry, Andrea Fassbender, A. Bourbonnais, Sophie Clayton, P. Gaube, M. Ormand, P.J.S. Franks, M. A. Altabet, D.J. Mcgillicuddy Jr.

OES Faculty Publications

Advances in technology and modeling capabilities are driving a surge in progress in our understanding of how ocean ecosystems mix and mingle on medium to small scales.

Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada

OES Faculty Publications

Marine sediments are globally significant sources of dissolved organic matter (DOM) to the oceans, but the biogeochemical role of pore-water DOM in the benthic and marine carbon cycles remains unclear due to a lack of understanding about the molecular composition of DOM. To help fill this knowledge gap, we used 1H nuclear magnetic resonance (NMR) spectroscopy to examine depth variability in the composition of pore-water DOM in anoxic sediments of Santa Barbara Basin, California Borderland. Proton detected spectra were acquired on whole samples without pre-concentration to avoid preclusion of any DOM components from the analytical window. Broad unresolved resonance (operationally …

Volcanogenic Pseudo-Fossils From The ~3.48 Ga Dresser Formation, Pilbara, Western Australia, David Wacey, Nora Noffke, Martin Saunders, Paul Guagliardo, David M. Pyle

OES Faculty Publications

The ~ 3.48 billion-year-old Dresser Formation, Pilbara Craton, Western Australia, is a key geological unit for the study of Earth's earliest life and the habitats it occupied. Here, we describe a new suite of spheroidal to lenticular microstructures that morphologically resemble some previously reported Archean microfossils. Correlative microscopy shows that these objects have a size distribution, wall ultrastructure, and chemistry that are incompatible with a microfossil origin and instead are interpreted as pyritized and silicified fragments of vesicular volcanic glass. Organic kerogenous material is associated with much of the altered volcanic glass; variable quantities of organic carbon line or fill …

Temporal Changes In Submarine Groundwater Discharge In A Georgia Salt Marsh, Tanner C. Avery, Jacque L. Kelly

Earth, Environment & Sustainability: Faculty Presentations (1988-2022)

No abstract provided.

An Integrated Machine Learning Geological Field Tool In The Age Of Big Data And Drones, Guillermo Vargas

Open Access Theses & Dissertations

Unmanned aerial vehicles (UAVs) and machine learning are relatively new research tools in the geosciences that can be used to collect and analyze large data sets rapidly. We combine the power of rapid data collection using unmanned aerial vehicles with machine learning algorithms to develop a field-based system to identify targeted geological features. For data collection, we have used a commercial-grade UAV which carried visible-wavelength and multispectral (visible- infrared) cameras. We analyzed the data with machine learning and machine vision algorithms that can classify rock units exposed in a field area. We have identified algorithms that in previous literature have …