Hydrology Commons^™

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 …

Image Processing Techniques For Water Droplet Penetration Time And Contact Angle Estimation, Sai Balaji Jai Kumar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Water droplet behavior on soil surfaces plays a critical role in numerous environmental processes, including soil erosion, hydrological dynamics, and ecosystem health. Accurate characterization of soil water repellency, quantified by parameters such as water droplet penetration time (WDPT) and contact angles (WDCA), is essential for informed decision-making in agricultural management, forestry practices, and land-use planning. Despite the significance of these parameters, challenges exist in reliably estimating them due to the complex and dynamic nature of soil-water interactions. This thesis address challenges in estimating WDPT and WDCA, by leveraging state-of-the-art image processing techniques and machine learning algorithms. The research focuses on …

Effects Of Climate Change On (Semi)-Arid Ecosystems In The Southwestern United States, Charlotte Van Der Nagel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate change is considered amongst the most severe threats to terrestrial and aquatic ecosystems globally. Ecosystems in the southwestern United States have specifically been impacted by intense drought conditions since 2000. Higher temperatures combined with altered precipitation stresses many ecosystems; however, ecosystem specific responses to such stressors may vary. Here, the effects of climate change on semi-arid ecosystems are analyzed for some of the most vulnerable ecosystems in the southwestern United States: lacustrine, riparian, and dryland ecosystems.

Lakes and reservoirs in arid environments often serve as drinking water sources and recreational areas where high water quality is essential. Climate change …

Radiogenic Isotope And Ionic Concentration Ratios Reveal Hydrologic Mixing, Subsurface Residence Time, And Cross-Basin Transfer In A Snow-Fed Mountain Karst Watershed, Nathaniel Ashmead

Boise State University Theses and Dissertations

Snow-fed karst aquifers support various complex ecosystems and provide a vital water source to communities worldwide. Due to their nature and distribution, these watersheds may be particularly vulnerable to the effects of climate change. Water resource managers can mitigate uncertainty from climate impacts with accurate predictions of future water availability provided by hydrologic models. While many such models exist, their effectiveness at predicting streamflow in snow-fed karst watersheds is limited by a lack of insight into the significance of cross-basin groundwater transfers. This study used radiogenic isotope and ionic concentration ratios as natural tracers to detect cross-basin transfer between two …

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 …

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 …

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 …

Revealing The Ongoing Speleogenetic Processes In An Underwater Cave Through The Application Of Natural Radionuclides And Stable Isotopes: Case Study From The Hypogene Buda Thermal Karst, Anita Erőss, Katalin Hegedűs-Csondo, Petra Kovács-Bodor, Dénes Szieberth, Ákos Horváth, György Czuppon, Andrea Mindszenty Dr, Szabolcs Leél-Őssy, Judit Mádl-Szőnyi

International Journal of Speleology

The underwater Molnár János Cave in the hypogene Buda Thermal Karst system (Budapest, Hungary) provides a unique site to study the effects of flowing groundwater and the interplay of fluids of different origin. The aim of the present study is to characterize the groundwater in different parts of the cave with temporal resolution, hence describe the recent speleogenetic processes within the cave. This study uses natural radioisotopes (uranium, radium, and radon) besides stable isotope ratios of oxygen and hydrogen to identify the different fluid components. The results show that the majority of the cave is situated in the flow path …

Populations Of The Stygobiotic Amphipod Palearcticarellus Pusillus (Martynov, 1930) Maintain Genetic Connectivity Between The Mountain Springs And The Deep Bottom Habitats Of Lake Teletskoye (Altai Mountains, Russia), Ivan Marin, Liubov Yanygina, Svetlana Ostroukhova, Dmitry Palatov

International Journal of Speleology

The diversity of underground fauna is often associated with the presence of karst areas, which have extensive underground cavities and connecting channels. Non-karst areas, however, make up a larger portion of the planet’ surface, and our understanding of the distribution and dispersal abilities of underground fauna in these areas currently remains limited. During a recent study of the diversity of stygobiotic crustaceans in the mountain streams of the Kurai Mountain Range (Altai, Russia), a small-sized species of crangonyctid amphipod, Palearcticarellus pusillus (Crustacea, Amphipoda, Crangonyctidae) was found in high-altitude springs. This species has been previously known only from deep-water habitats in …

The Hydrological Impacts Of Woody Plant Encroachment On Coastal Tallgrass Prairie Of Texas, Zhiwei Guo

LSU Master's Theses

Globally, woody plant encroachment into grassland and savanna ecosystems impacts the hydrological functions of grasslands and associated wetlands. In the coastal tallgrass prairie of Texas, encroachment of woody plants has altered vegetation structure, but the hydrological impacts are poorly understood. In this study, I evaluated and quantified how woody plant encroachment affects hydrological processes on the pimple mounds and inter-mound freshwater marsh, including precipitation partitioning, infiltration in the vadose zone, groundwater recharge, and water volume in the inter-mound marsh. I randomly selected three pimple mounds with woody plants and three pimple mounds with tallgrass w to quantify hydrologic processes. The …

Impacts Of Morphological Changes On Water Residence Times In River Deltas, Md. Muzahidul Islam

LSU Master's Theses

Coastal river deltas possess substantial socioeconomic and ecological importance and are expected to encounter increasing risks because of global climate change. The long-term sustainability of many deltaic systems is at risk due to a mix of natural and human-induced factors. Deltas are characterized by their continuous reconfiguration of channels and floodplains due to allogenic and autogenic processes. Sediment supply and composition, sea level rise, vegetation, river discharge, and human development may affect the morphological evolution of river deltas. The timescales and patterns of hydrological transport within a river delta are important indicators of ecological function. One such metric, the water …

Sampling Potential Hydrologic Impacts From An Underground Fire Lit By The Gray Road Fire, West Medical Lake, Isaac T. Dunmore

2024 Symposium

Eastern State Hospital (ESH) dumped and buried construction related material along the south west shores of West Medical Lake. Based on aerial photos from 1957, the dump was established with pine trees growing on the landfill. The dump is approximately 400 feet long, 50 ft wide and about 30 ft deep or about 6000,00 cubic feet of material. On August 18, 2023, during the Gray Road Fire, the buried site was ignited and has since continued to burn underground. Department of Health Services hired a consultant to analyze soils from the dump using the TCLP method for standard RCRA metals …

Pfas Variation Through A Wastewater Treatment Facility Process, Aaron A. Fuzak, Chad J. Pritchard

2024 Symposium

PFAS concentrations were measured at a wastewater treatment facility to see the effect the treatment process had on PFAS levels. Samples were collected following an initial clarifier, second clarifier, sand filtration system, ultraviolet light purification system, and then from the effluent produced by the facility and analyzed using EPA Method 533. The effluent from the treatment facility flows from a pipe that enters a wetland, where it evaporates or infiltrates the groundwater. Municipal and septic treated systems are considered possible point sources for PFAS contamination in groundwater. Sampling levels of PFAS after treatment will give insight into the concentrations and …

Preliminary Analysis Of Per-And Polyfluoroalkyl Substances (Pfas) In Surface Waters Of The West Plains Region Of Spokane County, Jerusha Hampson

2024 Symposium

Per-and Polyfluoroalkyl Substances (PFAS) have become a national issue as regulatory limits for these toxins have just recently been put into the Clean Water Act. The West Plains has been significantly impacted by PFAS contamination due to the decades-long use of aqueous film-forming foam (AFFF) for firefighting training at both Fairchild Airforce Base and the Spokane International Airport. Though research is still underway, it is known that PFAS contamination in West Plains groundwater is significant and widespread. This study focuses on West Plains surface waters, as there is currently less information about how these water bodies are impacted by PFAS. …