Physical Sciences and Mathematics Commons^™

Exploring The Consistency Of Flow Regimes Within And Among Ecoregions Of The Southeastern United States, Frank Paul Braun Iv

Electronic Theses and Dissertations

Human manipulation of river systems has long been a known contributor to the loss of freshwater biodiversity. By accounting for environmental causes of hydrologic variation among rivers, we can better understand how ecoregion mediates flow regimes and forecast species that may be at risk. Presumably, natural variation associated with ecoregion boundaries exerts strong influence on flow regimes, and may mediate relationships between other features (e.g., land use, dam operations) and hydrology. However, such between-ecoregion variation is poorly investigated, particularly at fine spatial and temporal scales. I characterized 10 hydrologic metrics, representing the five key dimensions of the flow regime (magnitude, …

Hydrologic Modeling With Remote Sensing For The Estimation Of Groundwater Resources Within The Sand River Catchment, South Africa, Sophia Bakar

Electronic Theses and Dissertations

The Sand River Catchment is an important tributary of the transboundary Limpopo River in South Africa, which spans Botswana, Mozambique, South Africa, and Mozambique. Groundwater is a critical resource in the region, especially in the context of population growth and climate change. Data are needed for proper management of these water resources. In regions where groundwater data are sparse in time, space, or both, the most promising solutions come from satellites and hydrologic models. Regional literature suggests that the Soutpansberg Mountains, located within the Sand Catchment, are high-elevation water towers with uncertain groundwater resources. Improved understanding of groundwater resources in …

Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer

Electronic Theses and Dissertations

Tidal rivers are landward portions of estuarine systems constituting the union between coastal, tidally controlled settings and rivers, where fluvial processes dominate. In these reaches, river discharge (mean flow) and tides are the two most important mechanisms in controlling geophysical flows. The processes governing water levels and current amplitudes in tidal rivers are highly nonlinear and modulated by external forcings- thus requiring sophisticated techniques for accurate prediction and forecasting. Physical oceanographers and estuarine physicists tend to limit their study area to the maximum extent of the horizontal tide (salinity intrusion), not the most landward point influenced by tidal water levels. …

Overlapping Scales Of Place Based Indigenous Knowledge And Hydroclimate In Australia, Rachel L. Coleman

Electronic Theses and Dissertations

Indigenous Peoples have been monitoring and adapting to uncertainty and change in their local regions for millennia, resulting in a holistic view of the interlinkages within the occupied complex socio-environmental systems. This research consists of investigating the overlapping scales of knowledge within Indigenous Australian seasonal calendars and colonial methods of hydroclimate assessment for improving adaptability to climate change impacts.

The analyses began with a sample of 25 Indigenous seasonal calendars providing a glimpse into interlinkages among biota, environment, and meteorology of the localised regions. Across the calendars, five themes of information and multiple categories within these themes became apparent and …

Giving Form To Flow: Modeling The Paleohydrological Context For Human Settlement And Water Use In The North-Central Coast Of Peru, Elizabeth Leclerc

Electronic Theses and Dissertations

Within coastal Andean archaeology there is a growing emphasis on the roles of hydrology and hydrological knowledge in Andean strategies for water management, settlement, and land use. Hydrological methods can not only help reconstruct past water environments but also illuminate the influence of changing climates and conditions in the Andean highlands on coastal water flows. Through a case study of the Supe River basin in north-central coastal Peru, focusing on the period from 5000 to 3000 calibrated radiocarbon years before present (cal. BP), I review several hydrological methods useful for archaeological study. I then combine these to develop a paleohydrological …

Numerical Modeling Of Controlling Factors For Formation Of Unconformity-Related Uranium Deposits In Sedimentary Basins, Jiayue Shen

Electronic Theses and Dissertations

Unconformity-related uranium (URU) deposits are the most profitable uranium deposits in the world. Among those deposits, the Athabasca Basin hosts the world’s largest high-grade uranium deposits. A series of numerical experiments regarding the effect of uranium source location, fault location, and fault dip angle on the formation of URU deposits have been conducted by using software TOUHREACT.

Simulation results suggest that although both sandstone-sourced and basement-sourced models can generate economical deposits, basement-sourced models are more likely to form larger deposits since uranium-carrying fluid only needs to move a shorter distance to reach the structural trap for further ore forming reaction. …

Examining Summertime Melt And Temperatures In The North Pacific Cordillera, Ingalise Kindstedt

Electronic Theses and Dissertations

Temperature changes in glaciated regions are of immediate concern for estimates of future sea level rise. Alaska and the surrounding region contain over 40 mm of potential sea level rise in its many alpine glaciers, which are experiencing some of the highest rates of mass loss globally. However, records of both past and present temperatures in the region’s alpine sectors are sparse and limited in temporal and spatial extent. Here I examine the application of MODIS land surface temperatures and layers of refrozen melt in ice cores as temperature indicators in the St. Elias and Alaska Ranges. First, I find …

Quantifying The Impacts Of Land Use, Management And Climate Change On Water Resources In Missouri River Basin, Arun Bawa

Electronic Theses and Dissertations

A location-specific evaluation of hydrological landscape responses concerning past and projected climate and land use land cover (LULC) changes can provide a powerful intellectual basis for developing efficient and profitable agroecosystems, and overcoming uncertain and detrimental consequences of LULC and climate shifts. This dissertation assessed the impacts of land use, management, and climate change on water resources in the Missouri River Basin (MRB) through four specific studies that included: (i) to study the responses of leached nutrient concentrations and soil health to winter rye cover crop (CC) under no-till corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation, (ii) to …

A Hydrologic Climate Study For An Arid Region, Ali Alsubeai

Electronic Theses and Dissertations

Water is the most precious natural resource in arid regions due to the limitation of water resources, expanding population, and increasing volumes of industrial and domestic waste. The purpose of this research was to evaluate methods to estimate water quantity in an arid region. The research consisted of three separate studies. In the first study, hydrologic models used to estimate water quantity were evaluated for suitability of use in arid regions. Most hydrologic models that have been used in arid regions were originally developed for humid regions. Rainfall events in arid regions can be characterized as short-term, high intense rainstorms …

Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan

Electronic Theses and Dissertations

In September 2008, Hurricane Ike swept through the Gulf of Mexico striking the Gulf Coast, claiming hundreds of lives and causing billions of dollars in damage. The hurricane left behind elevated sea salt concentrations in the soil and groundwater, preventing the unaided return of live oaks and other species to the island. To determine effective ways to ameliorate the elevated Na⁺ concentrations in the soil, eight treatments were applied to the soil and combinations of three species of plants, live oak (Quercus virginiana), hybrid bald cypress (Taxodium ‘T406’), and yellow hibiscus (Hibiscus hamabo …

Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause

Electronic Theses and Dissertations

The Saltville valley in southwestern Virginia is home to Quaternary localities containing paleontological and archaeological remains. Historically the valley has been mined for salt and the small lakes, ponds and springs along the valley floor have a brackish signature. A preliminary report on the site’s ostracode fauna suggested that the site’s water was not always saline. This study analyzed modern and Quaternary ostracodes to understand the valley’s hydrologic and chemical evolution. Sediments contained primarily freshwater species, including the environmentally sensitive Candona crogmaniana. The presence of Pelocypris tuberculatum and a new Fabaeformiscandona species throughout a vertical section spanning the latest Pleistocene …

Utilizing The Public On Public Lands: The Application Of Community Science To Monitor And Model Erosion In National Forests, Jacob L. Hansen

Electronic Theses and Dissertations

Unpaved forest roads are adversely affecting coldwater streams through excessive erosion and the subsequent sedimentation of adjacent waterways. To help identify areas of concern, Trout Unlimited (TU) in the Southern Appalachian region developed a Community Science initiative to gather data on sediment sources and stream-road crossings. Volunteers were recruited and trained to monitor road and trail conditions and collect and submit data using a Survey123 application on their cell phones. Analysis of the contributed data reveals statistical connections between drainage type and both erosion level and stream sedimentation. The contributed data were also included as a calibration for the lite …

A Groundwater Flow Model To Aid In Water Resource Management For The Carraipia Basin In The Coastal Semi-Arid Region Of La Guajira State (Colombia), Efren D. Gomez Arevalo

Electronic Theses and Dissertations

About 160,000 inhabitants live in the 1,600 square kilometers Carraipia River Basin located in northeastern Colombia and northwestern Venezuela. Historically, water has been supplied to the inhabitants in this arid coastal region by shallow dug wells. Water supplied by these wells is frequently of poor quality due to high concentrations of total dissolved solids (TDS). Recently, due to the increasing demand for water, numerous deep wells have been drilled in the region to supply water to rural and urban areas from deep aquifers. Colombian agencies seek more quantitative information on groundwater resources, driven by increasingly severe water shortages over the …

Storm Sampling To Assess Inclement Weather Impacts On Water Quality In A Karst Watershed: Sinking Creek, Watauga Watershed, East Tennessee, Porcha Mccurdy

Electronic Theses and Dissertations

Escherichia coli changes in Sinking Creek, an impaired water body in the Watauga watershed of northeast Tennessee, were assessed during storm events using water samples collected with ISCO automated samplers during eight storms at two locations. Turbidity and electrical conductivity (EC) data loggers were deployed in the creek, and dissolved oxygen (DO) was measured in situ to test the stream’s water quality and reaction to inclement weather. Cotton fabric was deployed at both locations and sent to an external lab to test for the presence of Optical Brighteners (OB), which are indicators of residential wastewater. E. coli and turbidity at …

Changes In Land Use Land Cover (Lulc), Surface Water Quality And Modelling Surface Discharge In Beaver Creek Watershed, Northeast Tennessee And Southwest Virginia, Tosin James

Electronic Theses and Dissertations

Beaver Creek is an impaired streams that is not supporting its designated use for recreation due to Escherichia coli (E.coli), and sediment. To address this problem, this thesis was divided into two studies.

The first study explored changes in Land Use Land Cover (LULC), and its impact on surface water quality. Changes in E.coli load between 1997-2001 and 2014-2018 were analyzed. Also, Landsat data of 2001, and 2018 were examined in Terrset 18.31. Mann-Whitney test only showed a significant reduction in E.coli for one site. Negative correlation was established between E.coli load, and Developed LULC, Forest LULC, and …

Spatial And Temporal Controls On Streamflow Variability In The San Juan Mountains, Colorado, Christopher Lewis Hancock

Electronic Theses and Dissertations

This project characterizes and examines changes to the annual hydroclimatic cycle throughout alpine regions of Colorado with a focus on trends in snowpack and snowmelt hydrology. Datasets analyzed for this research include 79 SNOTEL sites throughout Colorado (24 in the San Juan Mountains) which provide climate metrics for Water Years 1988-2018. Impacts on streamflow are evaluated in the San Juan Region through a network of 11 USGS stream gauges. Correlation matrices and linear regression methods examine the relative controls on the magnitude and timing of discharge, and trend detection using the regional Kendall test quantifies the rate of change within …

2d Electrical Resistivity And Hydrological Study Of A Solute Plume’S Migration Pathway Through Sandy Loam Within Nacogdoches County, Texas, Usa, Tyler Tandy, Wesley Brown, Kevin Stafford

Electronic Theses and Dissertations

combined geophysical and hydrological study was conducted in a sandy loam near the campus of Stephen F. Austin State University in Nacogdoches, Texas. The study area contained three preinstalled piezometers which are located in the Sparta Sand of the Eocene Claiborne Group, a regressive tract of the Eocene sea. Electrical DC resistivity surveys were conducted across one fifty-six-meter-long traverse using AGI’s multi-electrode SuperSting R8 WIFI RES/IP/SP system, which allowed for rapid and reliable data collection. The resistivity line was surveyed using the dipole-dipole array configuration, which has been proven to produce high-quality horizontal resolution. Over the duration of fourteen days, …

Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray

Electronic Theses and Dissertations

Over the past two decades, total nitrogen (TN) concentrations have increased in Casco Bay (CBEP 2015). The sources of the increased nitrogen are poorly understood but occur with simultaneous population growth and land use changes. The total riverine nitrogen load to Casco Bay was previously estimated by Liebman and Milstead (2012) using the United States Geologic Survey’s (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model. The SPARROW model uses watershed characteristics, regional monitoring data and nitrogen source data to estimate nitrogen loading but was not validated using measurements of nitrogen in the Casco Bay watershed. This study attempts to …

The Impacts Of Land Use And Land Cover Change On Water Quality In The Big Sioux River: 2007-2016, Dinesh Shrestha

Electronic Theses and Dissertations

Between 2006 and 2012, conversion of 485,000 acres of grassland to cropland in eastern South Dakota was reported. In 2012, the Big Sioux River (BSR) running through most of eastern South Dakota was listed among the dirtiest rivers in the nation. This rating convinced state authorities to study trends of land cover changes in the BSR watershed and its association with BSR water quality with respect to increases in nitrate levels. This research i) quantifies spatial and temporal changes in the land cover types within the BSR watershed, and ii) identifies any correlation between these changes and changes in BSR …

Stream Dynamics In The Headwaters Of Post-Glacial Watershed Systems, Brett Gerard

Electronic Theses and Dissertations

This dissertation summarizes research examining watershed processes across Northern New England, with an emphasis on the Central and Coastal regions of Maine. The research presented here focuses on the linkages between watershed geomorphic conditions, climate, and surface flow regimes driving stream channel hydraulic conditions and bed dynamics governing channel geometry. The geologic and human history of the landscape provides the context in which earth surface processes are examined within the dominant physiographic settings in Maine to describe vulnerabilities to climate change. Results are summarized to support the development of sustainability solutions for forecasted watershed management problems by natural resource management …

Depositional Environment And Facies Analyses Of The Owl Mountain Province, Fort Hood Military Installation, Bell And Coryell Counties, Texas, Jacob Meinerts

Electronic Theses and Dissertations

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and is characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges of the plateaus host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be part of a series …

The Effects Of Seasonal Variations In Chemistry And Hydrology On The Microbial Community And Its Sulfide Oxidation Potential In A Naturally Acidic Maine Stream, Raymond C. Kahler Iii

Electronic Theses and Dissertations

Sulfide minerals oxidize through interaction with water and oxygen, releasing hydrogen ions. The process often occurs naturally near metal sulfide deposits, and can be accelerated through mining. Microorganisms accelerate the rate of sulfide oxidation. Acidified streams typically contain high metal concentrations (e.g. aluminum) and microbes in these systems may develop resistances to metal toxicity. Stream flow can affect sulfide oxidation and microbial community structure. Baseflow can influence stream chemistry from interactions with the surrounding bedrock, while stormflow affects stream chemistry and the local microbial community through dilution and addition of microbes transported by runoff. Microbial community composition is affected by …

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords

Electronic Theses and Dissertations

Coal has a questionable future with the potential exhaustion of available coal. Alternate sources of energy production should be considered, such as hydropower dams, or the more environmentally friendly, Run of River (RoR) hydropower system. This study seeks to answer the question: What is the potential for RoR hydroelectric systems in Eastern Kentucky counties with significant decreases in coal production and employment? I hypothesize that GIS will identify suitable sites within Pike County for RoR systems. Site suitability for Eastern Kentucky was assessed and determined that Pike County did not have a suitable physical environment for RoR systems. The power …

Paleoflood Hydrology And Basin Morphometric Characteristics Related To Flooding In The Colorado Front Range, Natalie Trivino

Electronic Theses and Dissertations

Flooding hazards are common in the Colorado Front Range due to the steep, complex terrain of the mountains where waters quickly spill out onto the most populated region of Colorado. This region has experienced numerous catastrophic floods, such as the 2013 Front Range Floods, the Fort Collins Flood of 1997, and the Big Thompson Canyon Flood of 1976 to name a few. The objective of this study was to analyze basin morphometric characteristics of several drainage basins throughout the Colorado Front Range South Platte River tributaries and determine how these characteristics relate to extreme flooding. This was done through three …

Modernized Approach For Generating Micro-Layering And Macro-Heterogeneous Structures In Porous Media For Use In Transmitted-Light Method Flow Visualization Experiments, Aaron A. Jones

Electronic Theses and Dissertations

Image capturing in flow experiments has been used for fluid mechanics research since the early 1970s. Interactions of fluid flow between the vadose zone and permanent water table are of great interest to researchers because this zone is responsible for all recharge waters, pollutant transport and even irrigation efficiency for agriculture. Griffith, et al. (2011) developed an approach where constructed reproducible “geologically realistic” sand configurations are deposited in sand-filled experimental chambers or cells for light-transmitted flow visualization experiments. This method creates reproducible, reverse graded, layered (stratified) thin-slab sand chambers for visualizing multiphase flow through porous media. Reverse-graded stratification of sand …

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …

Groundwater Flow Tracing In Carter Saltpeter Cave And Toll Branch, Carter County, Tn, Aaron G. Doyka

Electronic Theses and Dissertations

Groundwater tracing studies have shown a well-developed conduit system in the karst aquifer beneath the Buffalo Creek Watershed of Carter County, TN. Groundwater can quickly travel beneath topographic divides, transporting contaminants. Using GIS and field reconnaissance, two sites were selected for a two phase dye trace study. In May-June 2016 groundwater resurgences were located using activated carbon samplers, and in October-December 2016 flow velocities were measured using ISCO automatic water samplers. In study 1, a stream sinking in the back of Carter Saltpeter Cave was traced to its resurgence at Cave Springs Cave. In study 2, the dye mass centroid …

Vulnerability Assessment Of Groundwater To No3 Contamination Using Gis, Drastic Model And Geostatistical Analysis, Adela Beauty Adu Agyemang

Electronic Theses and Dissertations

The study employed Geographical Information System (GIS) technology to investigate the vulnerability of groundwater to NO₃ content in Buncombe County, North Carolina in two different approaches. In the first study, the spatial distribution of NO₃ contamination was analyzed in a GIS environment using Kriging Interpolation. Cokriging interpolation was used to establish how NO₃ relates to land cover types and depth to water table of wells in the county. The second study used DRASTIC model to assess the vulnerability of groundwater in Buncombe County to NO₃ contamination. To get an accurate vulnerability index, the DRASTIC parameters were …

Spatiotemporal Analyses Of Recycled Water Production, Jana E. Archer

Electronic Theses and Dissertations

Increased demands on water supplies caused by population expansion, saltwater intrusion, and drought have led to water shortages which may be addressed by use of recycled water as recycled water products. Study I investigated recycled water production in Florida and California during 2009 to detect gaps in distribution and identify areas for expansion. Gaps were detected along the panhandle and Miami, Florida, as well as the northern and southwestern regions in California. Study II examined gaps in distribution, identified temporal change, and located areas for expansion for Florida in 2009 and 2015. Production increased in the northern and southern regions …