Hydrology Commons^™

Evaluating Soil Loss From Ephemeral Gullies With Photogrammetry, Chinthaka B. Weerasekara

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

No abstract provided.

Groundwater Recharge Response To Reduced Irrigation Pumping In Western Nebraska, Justin Philip Gibson

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

Given current and continued investment in irrigation scheduling technologies, a need exists to better estimate the longevity and magnitude of water savings at watershed level to avoid the paradox of irrigation efficiency. This paradox occurs within a watershed as not all irrigation inefficiencies lead to the system losing water. For example, irrigation pumping rates in excess of crop water demand may lead to enhanced groundwater recharge or surface runoff that migrates to a stream. Thus, increases in efficiency may not lead to similar magnitudes of water savings. I hypothesize that water savings longevities are short given previous work demonstrating rapid …

Boundary Spanners And Trust Development Between Stakeholders In Integrated Water Resource Management: A Mixed Methods Study, Jodi L. Delozier

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

Natural resource issues are inherently complex, even more so are those that involve the management of water. Because watersheds tend to cross multiple jurisdictional and geographical boundaries, a diverse set of stakeholders are needed to develop appropriate and sustainable management policy. This research sheds light on the importance of boundary spanners assisting in the development of trust between stakeholders in integrated water resource management (IWRM). Previous literature has explored the advantages to boundary spanning leadership in business practice, emergency management, university and community management as well as fish and wildlife management, but has failed to address the area of integrated …

Distribution And Habitat Association Of The Northern Long-Eared Bat, Zachary A. Warren

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

Because of white-nose syndrome, the northern long-eared bat (Myotis septentrionalis) is experiencing rapid population declines across the majority of its range. This decline has prompted increased regulatory protection and thus an increased need for effective habitat management strategies. Insight into the species habitat associations, however, is a prior necessity to ensure management practices are biologically relevant. Understanding these relationships requires a holistic approach that addresses the multiple ways in which the species is interacting with its environment. The objective of my thesis was to address these relationships following a multi-scale approach that assessed the factors associated with roost …

A Comparison Of Vnir And Mir Spectroscopy For Predicting Various Soil Properties, Joshua R. Gates

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

Soil plays an important role in our daily lives, namely producing food, cleaning water and storing carbon. The ability to rapidly and cost-effectively quantify the various components of soils can help us understand and better manage this important resource. This study aims to compare the ability of visible near-infrared (VNIR) spectroscopy and mid-infrared (MIR) spectroscopy to quickly and accurately predict various important soil properties (electrical conductivity, soil pH, cation exchange capacity, exchangeable cations, phosphorus, carbon, beta-glucosidase enzyme activity and nitrogen). Prediction models were developed using partial least squares regression (PLSR) techniques. Three different calibration sampling methods were tested along with …

Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer

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

Ponderosa pine (Pinus ponderosa) is a dominant tree species across western North America. Its eastern distribution includes three populations in western Nebraska. This study assesses the distribution, structure and age of ponderosa pine woodlands in one of those regions, the Wildcat Hills. The Wildcat Hills have escaped severe wildfires seen in recent decades in other ponderosa pine regions. Nevertheless, the Wildcat Hills woodlands face multiple threats including climate change, wildfire, drought, pine beetles, and invasive species. Key to these threats is the stand structure of pine woodlands, which have increased in density across much of ponderosa pine’s range. …

Analysis Of Gravity Recovery And Climate Experiment (Grace) Satellite-Derived Data As A Groundwater And Drought Monitoring Tool, Anthony James Mucia

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

This research compares Gravity Recovery and Climate Experiment (GRACE) groundwater storage (GWS) and root zone soil moisture (RZSM) percentiles to measured data, other drought indicators (DIs) and indices, and stakeholder observations for the purpose of assessing the feasibility and usefulness of these products to detect drought conditions. GRACE percentiles were directly compared to historic groundwater percentiles at 89 Nebraska well locations. Spatial time-series correlations over CONUS were performed between GRACE GWS and RZSM and the U.S. Drought Monitor (USDM), Standardized Precipitation Index (SPI), and soil moisture parameters from several North American Land Data Assimilation System (NLDAS) models. A survey of …

A Comparative Study Of The Role Of Values In Reasoning About Socio-Hydrological Issues In Undergraduate Students From Developed And Developing Countries, Destini Petitt

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

In a world that is becoming increasingly connected and exploited, it is essential to understand how students’ values influence socio-scientific reasoning, particularly when dealing with complex, multifaceted, ever-connected water-related issues. This research strives to better understand stakeholder reasoning to provide teachers and decision-makers with ways to implement those stakeholders’ ideals into choices about complex socio-hydrological issues. Moreover, with 96% of research behavioral research being conducted on peoples from developed countries – who only represent 17% of the world’s population – this study strives to understand how peoples from developing countries – who represent 83% of the world’s population – reason. …

Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier

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

Even though wetlands provide a habitat for many plants and animals and numerous services for humans, they were not always treated as areas of value. Less than half of the United States’ pre-colonial wetlands have survived to the present day. Seeing a need to understand the remaining wetlands more fully, the Environmental Protection Agency developed the National Wetland Condition Assessment to monitor target wetlands throughout the country every five years.

This study is an intensification of the National Wetland Condition Assessment for Nebraska wetlands that allowed us to sample more areas of the state and gather additional information. During the …

Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer

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

Streambed hydraulic conductivity (K) is known to be spatially and temporally heterogeneous, but few attempts to understand the controls on temporal variability have been made. This study documents temporal K transience and demonstrates how hydraulic, geophysical, and sedimentological methods can be combined to understand the processes that give rise to changes in streambed K. Falling head permeameter tests and slug tests were conducted to determine vertical K (K_v) and K (slug test K), respectively. These tests were repeated three times over a twelve-week period on the same grid at a depth of 0.5 …

The Impact Of Land Use On Nitrate-N Movement And Storage In The Vadose Zone Of The Hastings’ Whpa, Craig Adams

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

Nebraska has one of the largest agricultural economies in the United States and relies heavily on irrigation and fertilizer application to maintain crop yields. Over-irrigation and continuous application of nitrogen (N) in many areas has led to accumulation of nitrate-N in soils and sediments throughout the state’s vadose zone. Because nitrate-N is both persistent and mobile, groundwater concentrations in many areas of Nebraska and other agriculturally intensive states are increasing. Nitrate-N contamination of public and private drinking water supplies that utilize groundwater are of particular concern. Vadose zone sampling is an important method for rapidly assessing the effect of changing …

Motivations, Specializations, Identities, And Constraints Associated With Hunting In Nebraska, Alisha Grams

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

No abstract provided.

Improving The Accuracy Of Cosmic-Ray Neutron Probe Estimate Of Soil Water Content Using Multiple Detectors And Remote Sensing Estimates Of Vegetation, Xiaochen Dong

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

The recently developed Cosmic-ray Neutron Probe (CRNP) for estimating soil water content (SWC) fills a critical measurement gap between point scale methods and large scale measurements collected from remote sensing. CRNP works by measuring the change in low-energy neutron intensity over time. However, the accuracy of CRNP to measure SWC is well known to be affected by other hydrogen sources (e.g. soil organic content, atmospheric water vapor, vegetation and surface water). This study focuses on the influence of rapidly growing vegetation in agricultural fields on the accuracy of the CRNP method. Here we use data from three long-term CRNP study …

Understanding Cigarette Butt Littering Behavior On Public Beaches: A Case Study Of Jekyll Island, Georgia, Maranda R. Miller

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

The world’s natural environment is degrading, and human behavior is a leading cause. Therefore, in order to address environmental problems it is important to understand the factors driving environmentally degrading behaviors and subsequently design behavioral interventions to alter undesirable behaviors.

One environmental issue of particular concern is toxins leeching from trash. Specifically, cigarette butts are of concern due to their prevalence in the environment. Cigarette butt discarding behavior is affected by personal attributes, but data regarding which personal attributes and how these affect discarding behavior is lacking. This thesis seeks to understand cigarette butt disposal on public beaches by exploring …

Soil Ecosystem Service Tradeoffs And Social–Ecological Resilience In The North Central Great Plains, Hannah E. Birge

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

Humans seek to improve their wellbeing by altering ecological processes to maximize the output of specific ecosystem services, which often leave the system vulnerable to unintended and undesirable side effects. Ecosystem services emerge from complex interactions among ecological structures and processes occurring at multiple scales. The degree to which an ecosystem maintains a predictable range of structures and processes in the face of disturbance can be described as its resilience. The 1930s Dust Bowl of the North American Great Plains is an example of a system reconfiguration and loss of resilience that was ultimately driven by human optimization for a …

Trophic Dynamics Of Flathead Catfish In The Missouri River Bordering Nebraska, Dylan R. Turner

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

Understanding the trophic dynamics of large, riverine ecosystems is complex and requires knowledge from several inputs and outputs of the ecosystem. Most riverine ecosystems have been altered in some way whether through damming, channelizing, or diverting water. The Missouri River is not immune to these anthropogenic alterations. The river has dams throughout its middle portion and is channelized from Sioux City, Iowa to its confluence with the Mississippi River. Flathead Catfish pylodictus olivarius are one of the most ecologically harmful introduced species but little research has looked at the influence native populations of Flathead Catfish have on native prey populations …

Fish And Macroinvertebrate Response To Restored Off Channel Habitats On The Lower Platte River, Nebraska, Caleb Uerling

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

Anthropogenic alterations to large rivers ranging from impoundments to levees have caused many rivers to no longer access the floodplain. The ecological integrity of floodplain rivers depends on the interaction between main-channel and floodplain habitats. Fish communities inhabiting floodplain habitats are often dictated by the type of habitat and conditions within that habitat. As restoration projects are undertaken it is imperative that managers understand how fish and macroinvertebrates respond to these events. We collected fish, macroinvertebrates, and habitat parameters on two restored floodplain habitats on the lower Platte River, Nebraska to answer questions about aquatic community response to floodplain restoration …

Integration Of Hydrogeophysical Datasets For Improved Water Resource Management In Irrigated Systems, Catherine E. Finkenbiner

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

Water scarcity is predicted to be the major limitation to increasing agronomic outputs to meet future food and fiber demands. With the agricultural sector accounting for 80 – 90% of all consumptive water use and an average water use efficiency (WUE) of less than 45%, major advances must be made in irrigation water management. Precision agriculture, specifically variable-rate irrigation (VRI) and variable-speed irrigation (VSI) systems, offers the technologies to address and manage for infield variability and incorporate that into management decisions. The major limitation to implementing this technology often lies in the management of spatial datasets and the development of …

Problematizing Socio-Scientific Issues: An Approach To Understanding Student Decision-Making Using Construal Level Theory, Ashley M. Peterson

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

Socio-scientific issues (SSIs) are challenges at the intersection of science and everyday life that require use of scientific knowledge, argumentation skills, personal values, and morals to articulate science-informed decisions. While addressing SSIs, the ways in which individuals define a problem will influence the solution or decision reached. The problem definition can differ along many dimensions, including content and construal level. A construal is a mental construction of the past and future, other places and people, and unlikely events. Construal Level Theory (CLT) suggests pro-environmental intentions are associated with abstract situations. I explore the application of CLT to teaching and learning …

Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans

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

As global warming, human conversion of natural landscapes to agricultural uses, and widespread biodiversity losses continue to alter the ecosystems we depend on, an understanding of the relationship between ecosystem structure, composition, and function is needed to maintain valuable ecosystem states and their associated functions. Research testing the limits of an ecosystem’s ability to maintain essential structure and functioning under disturbance conditions can aid in this goal.

In this study, I measured the relationship between plant diversity, community structure and functional traits, and their responses to added disturbances. I added disturbances representing those either caused or intensified by human activity …

Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann

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

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and …

River Otter (Lontra Canadensis) Distribution And Habitat Suitability In Nebraska, Nathan R. Bieber

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

River otters (Lontra Canadensis) were extirpated in Nebraska by the early 1900’s, but in 1986, the Nebraska Game and Parks Commission (NGPC) began reintroduction efforts. Following reintroductions, the otter was listed as a tier-1 at-risk species in Nebraska. With increasing otter populations, NGPC is evaluating a de-listing plan. In order to inform de-listing efforts, I surveyed Nebraska’s rivers documenting otter sign and used modeling techniques to estimate otter distribution and habitat suitability.

Otter sign surveys were conducted on the navigable rivers of Nebraska. Occupancy modeling techniques were used to examine patterns in otter detections. The best model incorporated distance …

Resilience And Heterogeneity Following Fire In The Nebraska Sandhills, Jack R. Arterburn

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

The Nebraska Sandhills grassland is an expansive, semi-arid ecosystem characterized by vegetation-stabilized rolling sand dunes. The Sandhills grassland is managed for livestock production by seeking to minimizing disturbances, such as fire, that increase bare ground. The increase in bare ground following fire has contributed to the fear of fire leading to the emergence of a mobile sand dune state. We tracked vegetation response following a growing season wildfire that occurred during extreme drought conditions. In wildfire and drought conditions are when one would expect resilience to be overcome leading to a lack of vegetation recovery and a transition to a …

Adaptation To Climate Change Via Insurance And Financial Incentives, Eric R. Holley

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

Catastrophic climatic events have accounted for 72% of global insurance claims and totaled ~$1 trillion from 1980 to 2012. Costs are driven by socio-economic developments and an increased frequency and severity of climatic disasters in which climate change may have been a contributing factor. Climate change is projected to become a more prominent driver of these changes in the decades ahead. Government policies to reduce systemic risk have been the predominant approach for multi-level mitigation and adaptation to climate change. The analysis presented here shows how forceful and effective market-based approaches for adaptation and mitigation to climate change already operate …

The Cosmic-Ray Neutron Probe Method For Estimating Field Scale Soil Water Content: Advances And Applications, William A. Avery

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

The need for accurate, real-time, reliable, and multi-scale soil water content (SWC) monitoring is critical for a multitude of scientific disciplines trying to understand and predict the earth’s terrestrial energy, water, and nutrient cycles. One promising technique to help meet this demand is fixed and roving cosmic-ray neutron probes (CRNP). However, the relationship between observed low-energy neutrons and SWC is affected by local soil and vegetation calibration parameters. This effect may be accounted for by a calibrated equation based on local soil type and the amount of standing biomass. However, determining the calibration parameters for this equation is labor and …

Optimizing The Safety Margins Governing A Deterministic Design Process While Considering The Effects Of A Future Test And Redesign On Epistemic Model Uncertainty, Nathaniel B. Price

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

At the initial design stage, engineers often rely on low-fidelity models that have high uncertainty. Model uncertainty is reducible and is classified as epistemic uncertainty; uncertainty due to variability is irreducible and classified as aleatory uncertainty. In a deterministic safety-margin-based design approach, uncertainty is implicitly compensated for by using fixed conservative values in place of aleatory variables and ensuring the design satisfies a safety-margin with respect to design constraints. After an initial design is selected, testing (e.g. physical experiment or high-fidelity simulation) is performed to reduce epistemic uncertainty and ensure the design achieves the targeted levels of safety. Testing is …

Hydrologic Mediation Of The Spatial And Temporal Variability Of The Soil Carbon Dioxide Stable Isotopic Composition Of A Subalpine Watershed, Theresa Marie Lorenzo

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

The stable carbon isotopic composition of CO₂ (δ¹³C-CO₂) has been studied as an indicator of changes in ecosystem CO₂ exchange. Soil moisture is an important factor in ecosystem CO₂ exchange through its influence on physiological and soil physical processes. However, the majority of previous research analyzing the influence of soil moisture on soil and soil-respired δ¹³C-CO₂ has been conducted with limited consideration of topographical variation, which controls the distribution of soil moisture across a landscape. This study characterized the stable isotopic composition (δ¹³C) and concentrations of soil CO …

Simulation Of Meteorological Fields For Icing Applications At The Summit Of Mount Washington, Sandra L. Jones

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

Hazards related to in-cloud icing on aircraft and ground structures are important considerations for structural design, risk mitigation and operations. A variety of robust ice accretion algorithms exist for application dependent purposes; however, these algorithms are often dependent on reliable meteorological input data to be of use. This study investigates the potential for predicting meteorological parameters relevant to in-cloud icing episodes at ground level using the Weather Research and Forecasting (WRF) model. Model performance with regards to explicit simulation of super-cooled cloud liquid water content, cloud droplet diameter, temperature, and wind speed is evaluated against measurements collected at the summit …

Improving Time Structure Patterns Of Orthogonal Markov Chains And Its Consequences In Hydraulic Simulations, Juan C. Jaimes-Correa

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

Rainfall¹ occurrences understood as rain events are relevant for agricultural practices because temporal distribution of rainfall highly affects yield production. A few stochastic models satisfactorily generate daily rainfall events while preserving temporal and spatial dependence among multiple sites. I evaluated an extension on the traditional Orthogonal Markov chain (TOMC) model in reproducing the temporal structure of rainfall events at multiple sites in Florida (FL), Nebraska (NE) and California (CA). In addition, a simulation of watershed runoff from rainfall events, reproduced by a single- and multi-site weather generator, was conducted. Results shows that (i) a temporal structure extended …

Building Upon Common-Pool Resource Theory To Explore Success In Transitioning Water Management Institutions, Christina M. Hoffman

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

Nebraska, like many regions around the world, is faced with the challenge of adapting to a new era in water management. Increasing demands for water resources, mounting concerns over threatened and endangered species, and obligations to abide by interstate water allocation agreements have motivated Nebraska to revisit traditional water management approaches. However, although Nebraska’s water management institutions have undergone much change, little research exists on the influence these changes have had on the ability of water institutions to successfully manage water allocations. This research (1) qualitatively explores the perspectives and experiences of stakeholders in the overappropriated region of the Platte …