Physical Sciences and Mathematics Commons^™

Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division

Conservation and Survey Division

No abstract provided.

Pre-Tertiary Subcrop Rocks In The Nebraska Panhandle, Conservation Annd Survey Division

Conservation and Survey Division

No abstract provided.

Configuration Of The Base Of The Principal Aquifer, Conservation And Survey Division

Conservation and Survey Division

No abstract provided.

Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

Addressing groundwater depletion problems in heterogeneous aquifer systems is a challenge. The heterogeneous Ogallala Aquifer, a critical source of groundwater in the central United States, has undergone decades of decline in water levels due to pumping. This project aims to build a robust groundwater model to evaluate optimal scenarios for sustainable use of the groundwater resource within a section of the Ogallala aquifer located in the Middle Republican Natural Resources District (MRNRD). This study follows a comprehensive approach involving parameterization, construction, and optimization. The model is parametrized using hydraulic conductivity and recharge values obtained from a random forest-based machine learning …

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 …

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 …

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 …

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 …

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 …

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, …

Population Demography, Occupancy, And Connectivity Of Invasive Bigheaded Carp In The Platte River, Nebraska And Its Tributaries, Blake W. Logan

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

Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis, collectively referred to as bigheaded carp, are invasive species in the United States of America that have expanded their range throughout the Missouri River basin in the last three decades. It may be desirable to develop management plans directed at the monitoring, control, or removal of bigheaded carp within the Missouri River basin. However, a knowledge gap exists regarding bigheaded carp ecology in Missouri River tributaries, which may be important for the development of management plans. As such, this study characterized bigheaded carp population demographics, occupancy, and connectivity in …

Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik

Conservation and Survey Division

No abstract provided.

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu

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

The uncertainty in model projections of future precipitation across the Sahel has persisted across many generations of Earth System Models (ESMs), with some models predicting drying and others moistening across this region. These discrepancies in future projections pose a challenge for stakeholders and decision makers. Many projections of Sahel precipitation found in the ESMs participating in the sixth phase of Coupled Model Intercomparison Project (CMIP6) show a zonal dipole in precipitation trend, with moistening across the Central and Eastern Sahel and drying projected for the Western Sahel. Previous studies have connected precipitation variability across the Sahel to changes in various …

Effect Of Biomass Water Dynamics In Cosmic-Ray Neutron Sensor Observations: A Long-Term Analysis Of Maize-Soybean Rotation In Nebraska, Tanessa Morris

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

The precise measurement of soil water content (SWC) is crucial for effective water resource management. This study utilizes the Cosmic Ray Neutron Sensor (CRNS) for area-averaged SWC measurements, emphasizing the need to consider all hydrogen sources, including the time-variable ones like plant biomass and water content. Chapter 1 presents a background on soil moisture estimation, CRNS technology, and an overview of the study. It discusses various soil moisture measurement techniques, highlights the gap in knowledge addressed by CRNS technology, explains CRNS functionality and advancements, and outlines the study's motivations and methods.

Chapter 2 reports a study conducted near Mead, Nebraska, …

Demographic Consequences Of Off-River Nesting For Piping Plover (Charadrius Melodus) And Interior Least Tern (Sternula Antillarum Athalassos) In The Lower Platte River System, Nebraska, Elsa M. Forsberg

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

Piping plovers (Charadrius melodus; hereafter, plovers) and interior least terns (Sternula antillarum athalassos; hereafter, terns) are two avian species that nest along the Lower Platte River system (LPRS) in Nebraska. In the LPRS, river sandbars provide natural nesting habitat, but off-river sites provide substantial nesting habitat especially when sandbar habitat is scarce. Although presumed to be important for the persistence of plovers and terns, off-river habitat is not self-sustaining and predicted to decline. Understanding the vital rates of plovers and terns in the LPRS will inform the role of off- river sites in the future conservation …

Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr.

Conservation and Survey Division

What is groundwater? Groundwater is water that fills and moves between spaces in underground rocks, gravel, sand, or other materials.

Publications And Other Works By R. F. Diffendal, Jr., Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Articles
Chapters in Books
Books
Field Guides
Geologic Maps
Other Maps
Cover Photographs
Other Photographs
Newspaper and Other Articles
Test-Hole Logs
Television Programs
Geonotes
Abstracts
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Manuscripts Accepted (A), Submitted (S), or in Preparation (P)
Geologic Maps in Press
Geologic Maps-Nebraska
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Updated March 2024

Water-Level And Recoverable Water In Storage Changes, High Plains Aquifer, Predevelopment To 2019 And 2017 To 2019, Virginia L. Mcguire, Kellan R. Strauch

United States Geological Survey: Water Reports and Publications

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial groundwater irrigation (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2019 and from 2017 to 2019.

Water-level changes from predevelopment to 2019, by well, ranged from a rise of 86 feet to a decline of 265 feet; the range for …

Nebraska Statewide Groundwater-Level Monitoring Report 2023, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Nawaraj Shrestha, Jeffrey Westrop

Conservation and Survey Division

This report is a synthesis of groundwater-level monitoring programs in Nebraska. It is a continuation of the series of annual reports and maps produced by the Conservation and Survey Division (CSD) of the University of Nebraska in cooperation with the U.S. Geological Survey (USGS) since the 1950s. Groundwater-level monitoring began in Nebraska in 1930 to survey the state’s groundwater resources and observe changes in its availability on a regular basis. The CSD and USGS cooperatively developed, maintained, and operated an observation-well network throughout the state. These two agencies were responsible for collecting and archiving this information, and for making it …

Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel

Conservation and Survey Division

No abstract provided.

Leveraging High Resolution Classifications And Random Forests For Hindcasting Decades Of Mesic Ecosystem Dynamics In The Landsat Time Series, N. E. Kolarik, Nawaraj Shrestha, T. Caughlin, J. S. Brandt

Conservation and Survey Division

No abstract provided.

Stage And Discharge Prediction From Documentary Time-Lapse Imagery, Kenneth W. Chapman, Troy E. Gilmore, Mehrube Mehrubeoglu, Christian D. Chapman, Aaron R. Mittelstet, John E. Stranzl Jr.

Department of Biological Systems Engineering: Papers and Publications

Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (> 40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as …

Population Demography Of A Glacial-Relict Stream Fish Mediated Via Anthropogenic Alteration, Joseph M. Spooner

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

Northern Pearl Dace Margariscus nachtriebi are a small-bodied glacial-relict fish species of greatest conservation need (SGCN) found throughout Canada and the northern United Sates. Their distribution within the Nebraska Sandhills Ecoregion is isolated from the northern core distribution of the species following the last glaciation period approximately 18,000 years ago. Headwater streams within the Nebraska Sandhills Ecoregion are predominately groundwater fed and provide the cool water temperatures needed to support Northern Pearl Dace and other glacial-relict SGCN. Headwater streams within the Nebraska Sandhills Ecoregion have been geomorphically altered through anthropogenic processes such as channelization whereby habitat homogenization has occurred. Evidence …

Habitat Heterogeneity In Nebraska Streams And Distribution Prediction For Tier-1 Cyprinids Using Multi-Scale Modeling Of Fluvial And Landscape Features, Connor P. Hart

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

Multiscale environmental processes determine in-stream habitat conditions which drive species distributions. Habitat constitutes the physical template upon which ecological processes occur and species conduct life stage activities. Habitat heterogeneity promotes biodiversity of aquatic systems. Stream classification informs freshwater conservation by providing a useful framework to account for habitat heterogeneity, often based on landscape regions of similar environmental processes. A greater understanding of landscape-based classification frameworks as means to classify stream systems may improve understanding of drivers of biodiversity. Using Nebraska as a case study, on a statewide scale, objectives were 1) to characterize habitat availability for several at-risk fish species, …

The Broadwater Formation (Pliocene) Of Nebraska And Southeastern Wyoming, Robert F. Diffendal Jr., James B. Swinehart

Robert F. Diffendal, Jr., Publications

The Broadwater Formation, initially defined in 1945, is a Pliocene-aged coarse-grained alluvial deposit in Nebraska and southeastern Wyoming. It is characterized by a complex stratigraphic history and debated geologic interpretations. The formation is a rich resource of groundwater for the citizens of Nebraska and the Central Great Plains. We aim to synthesize and redefine the Broadwater Formation, shedding light on its distribution, geological characteristics, and paleoenvironmental significance. While historical hypotheses on Broadwater Formation paleovalley trajectories suggested northwest-southeast trending valleys, later investigations proposed wind-driven erosional patterns to explain the unique topographic features observed. The Broadwater is divided into an unnamed Upper …

Connecting The Nebraska Water Quality Index To The Aquatic Microbial Community Of The North Platte River Basin, Nebraska, Paula R. Guastello

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

The Nebraska Water Quality Index, under development by the Nebraska Department of Environment and Energy, summarizes in a single value eight environmental parameters that have been monitored in Nebraska for nearly 20 years. Water quality parameters including those used in the Nebraska Water Quality Index have been shown in previous studies to impact bacterial growth. As such, this index has the potential to correlate with the freshwater microbial community. Here, I relate the Nebraska Water Quality Index to microbial community composition and structure using 16S rRNA gene amplicon sequence data collected from the North Platte River Basin, Nebraska. This index …

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Biological Systems Engineering: Dissertations and Theses

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Examining The Corn Seedling Emergence–Temperature Relationship For Recent Hybrids: Insights From Experimental Studies, Sahila Beegum, Charles Hunt Walne, Krishna N. Reddy, Vangimalla Reddy, Kambham Raja Reddy

Nebraska Water Center: Faculty Publications

Corn seedling emergence is a critical factor affecting crop yields. Accurately predicting emergence is crucial for precise crop growth and development simulation in process-based crop models. While various experimental studies have investigated the relationship between corn seedling emergence and temperature, there remains a scarcity of studies focused on newer corn hybrids. In the present study, statistical models (linear and quadratic functional relationships) are developed based on the seedling emergence of ten current corn hybrids, considering soil and air temperatures as influencing factors. The data used for model development are obtained from controlled soil plant atmospheric research chamber experiments focused on …

Analysis Of Wastewater Samples To Explore Community Substance Use In The United States: Pilot Correlative And Machine Learning Study, Marie A. Severson, Sathaporn Onanong, Alexandra Dolezal, Shannon L. Bartelt-Hunt, Daniel D. Snow, Lisa M. Mcfadden

Nebraska Water Center: Faculty Publications

Background: Substance use disorder and associated deaths have increased in the United States, but methods for detecting and monitoring substance use using rapid and unbiased techniques are lacking. Wastewater-based surveillance is a cost-effective method for monitoring community drug use. However, the examination of the results often focuses on descriptive analysis.

Objective: The objective of this study was to explore community substance use in the United States by analyzing wastewater samples. Geographic differences and commonalities of substance use were explored.

Methods: Wastewater was sampled across the United States (n=12). Selected drugs with misuse potential, prescriptions, and over-the-counter drugs …