Physical Sciences and Mathematics Commons^™

Environmental And Climatic Constraints On Large-Scale Camelina Production In Eastern Arkansas, Benjamin Robert Tracy

Graduate Theses and Dissertations

Camelina sativa is a cold weather crop that is typically grown in semi-arid environments in the Western United States, usually as a spring crop, but sometimes during the winter. Research analyzing climate data and soil hydrology is important to better understand the environmental and terrain conditions necessary for Camelina farming wherever it is proposed for large-scale production. This study focused on various conditions and constraints pertaining to the potential for Camelina as a crop biofuel in Eastern Arkansas. Due to interest in the economic potential of crop biofuels in this area, and in particular the low input costs for Camelina, …

Willingness To Pay For Irrigation Water Under Scarcity Conditions, Tyler Robert Knapp

Graduate Theses and Dissertations

Reliance of Arkansas agricultural producers on groundwater for irrigation has led to depletion of the Mississippi River Valley alluvial aquifer. Without intervention, consequences include insufficient groundwater to meet irrigation demand as well as drawdown of the deeper Sparta Aquifer, upon which communities in eastern Arkansas rely for non-agricultural use. Among proposed solutions to combat groundwater decline is the construction of off-farm surface water infrastructure to meet the irrigation needs of producers. Despite the importance of irrigated agriculture to Arkansas, there is little know about the economic value of irrigation water to producers. Thus, we implement a double-bounded dichotomous choice contingent …

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …

Asbestos Cement Pipe Condition Assessment And Remaining Service Life Prediction, Abiy Melles Ghirmay

Graduate Theses and Dissertations

This research details a condition assessment of asbestos cement (AC) pipe within in the Bella Vista Village Property Owners Association water distribution system. Bella Vista Village contains appropriately 300 miles of AC pipe with nominal diameters from 6-14 inch. The goal of the research is to determine the current condition of AC pipe within the system and predict future performance of the pipes. AC pipe samples were obtained from 23 locations disturbed across the distribution system with nominal pipe diameters of 6-8 inch. Estimates of current level of degradation were obtained using phenolphthalein staining and hardness measurements of each sample. …

Lidar-Assisted Extraction Of Old Growth Baldcypress Stands Along The Black River Of North Carolina, Weston Pierce Murch

Graduate Theses and Dissertations

The remnants of ancient baldcypress forests continue to grow across the Southeastern United States. These long lived trees are invaluable for biodiversity along riverine ecosystems, provide habitat to a myriad of animal species, and augment the proxy climate record for North America. While extensive logging of the areas along the Black River in North Carolina has mostly decimated ancient forests of many species including the baldcypress, conservation efforts from The Nature Conservancy and other partners are under way. In order to more efficiently find and study these enduring stands of baldcypress, some of which are estimated to be more than …

Optical Water Quality And Human Perceptions Of Rivers, Amie West

Graduate Theses and Dissertations

Understanding water quality dynamics in recreational rivers is integral in shaping management strategies that maintain ecosystem health, perceived value and appeal, and regional economic significance in a changing environment. Optical water quality describes the behavior of light in water as governed by its physical and chemical composition, and is among the strongest influences on human perceptions of water quality. Ethnohydrology is the study of culturally constructed knowledge and understanding of water. This work is the culmination of an interdisciplinary approach to water resources research—integrating optical water quality and ethnohydrology methods to recognize the intersection between measured water quality and visible …

Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile

Graduate Theses and Dissertations

This study investigated the effects of source water quality in Beaver Lake on the amount of chlorine (Cl) needed to develop decision support system to help guide chlorination practices in pre-treatment of source water. Chlorine demand assays were performed on water samples from Beaver Lake collected from the intake structure at Beaver Water District from March 2014 through August 2015, and using data from these assays, the two points of interest in this study were the Cl dose at which Cl residuals began to accumulate and the mean Cl demand occurring after that dose. Three methods of analysis were used …

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …

The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii

Graduate Theses and Dissertations

Organic matter (OM) in the environment acts as a nutrient, but may also act as a transport vector for harmful chemical compounds and bacteria. Acetate is a labile form of OM produced during fermentation in anaerobic lagoons used to store animal fecal-waste from concentrated animal feeding operations (CAFOs). Dry and liquid fertilizers from CAFOs pose a threat to groundwater by introducing excessive amounts of nutrients (e.g. OM, nitrate and ammonia), metals, and antibiotic compounds. In the epikarst of Northern Arkansas in the Buffalo River watershed additional input of labile dissolved organic carbon (DOC) from liquid CAFO waste-fertilizers was hypothesized to …

Algal Wastewater Treatment And Biofuel Production: An Assessment Of Measurement Methods, And Impact Of Nutrient Availability And Species Composition, John F. Chamberlin

Graduate Theses and Dissertations

In order to move towards a more sustainable future, human civilization will need to decrease its impacts on air and water quality and minimize consumption of fossil fuels. Using algae for wastewater treatment and biofuel production offers one approach to progress towards these goals simultaneously. Algae are capable of removing nutrients from wastewater and carbon dioxide from the air, and the biomass formed in that process can be used to generate a wide-range of products including fertilizer or fuels that could power combustion engines, power plants, or zero-emission fuel cell vehicles. Using wastewater for biofuel production has the potential to …

The Mass Flux Of Non-Renewable Energy For Humanity, Edwin Dale Solomon

Graduate Theses and Dissertations

The global energy supply relies on non-renewable energy sources, coal, crude oil, and natural gas, along with nuclear power from uranium and these finite resources are located within the upper few kilometers of the Earth’s crust. The total quantity of non-renewable energy resources consumed relative to the total quantity available is an essential question facing humanity. Analyses of energy consumption was conducted for the period 1800 – 2014 using data from the U. S. Energy Information Administration (EIA) and World Energy Production, 1800-1985 to determine the balance between non-renewable energy resources consumed and ultimately recoverable reserves. Annual energy consumption was …

Modifying A Cow-Calf Biophysical Simulation Model For Analyses Of Alternative Enterprises, Jennifer L. Lutes

Graduate Theses and Dissertations

Cow-calf producers in the United States, tasked with providing beef calves for the beef industry, have had a multitude of difficulties to overcome in recent years. Producers in northwest Arkansas were negatively impacted by high hay prices coupled with low beef cattle market prices due to severe drought experienced in portions of 2010, 2011, and 2012. During this time they also faced high grain prices, due to a record low harvest, combined with portions of the corn harvest diverted from human and animal feed to ethanol production. Tight lending policies of this time, reminiscent of the housing market crash in …

Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson

Graduate Theses and Dissertations

The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks. This process has created large volumes of brackish water that is very difficult to process and is often disposed of into injection wells. Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the reuse of flowback in future hydraulic fracturing operations.

Nanofiltration, a membrane separation …

Evaluation Of Conservation Practices Through Simulation Modeling And Tool Development, Gurdeep Singh

Graduate Theses and Dissertations

For the first objective, predicted impacts of selected Mississippi River Basin Initiative (MRBI) conservation practices (CPs) on sediment and nutrient loss were assessed. The study area was L’Anguille River Watershed (LRW), a priority focus watershed of the MRBI program and the simulated CPs were filter strip, critical area planting, grade stabilization structure, irrigation land leveling, irrigation pipeline, irrigation water management, and nutrient management. The Soil and Water Assessment Tool (SWAT) model was calibrated (1998 – 2005) and validated (2006 – 2012) for flow, sediment, total phosphorus (TP), and nitrate-nitrogen (NO3-N) at the Colt site (503 sq. km. drainage area) and …

Stratigraphic And Structural Analysis Of Middle Atoka Formation In Aetna Gas Field, Franklin, Johnson And Logan Counties, Arkansas, Ikramuddin Bahram

Graduate Theses and Dissertations

Arkoma basin is a prolific natural gas basin. The defining feature of this basin is the Atoka Formation that was deposited in the early-middle Pennsylvanian. The Atoka is held equivalent to the tectonic and structural evolution of the basin. This study focuses on one of the many gas fields in the Arkoma Basin in Arkansas to assess the stratigraphic and structural evolution that the strata in this particular field display.

Aetna Gas Field extends from T. 8N. R. 27 W to T. 9 N, R. 27 W and T. 8 N, R. 26 W to 8N, R. 27. Geographically, Aetna …

Is Chir Pine Displacing Banj Oak In The Central Himalaya? Socioeconomic Implications For Local People And The Conservation Of Oak Forest Biodiversity, Ankush Nautiyal

Graduate Theses and Dissertations

Various studies have suggested that chir pine (Pinus roxburghii) is replacing banj oak (Quercus leucotrichophora) in the Central Himalaya. Five sites with three different types of forests (banj oak, chir pine and mixed oak-pine) were sampled to compare the diversity of their vegetation and to assess the impact of this ongoing conversion on biodiversity. Soil samples collected from oak and pine forests were analyzed and compared. In addition, dendrochronology was used to obtain age estimates of chir pine and to understand the growth response of this species to precipitation. Also, samples of ectomycorrhizal fungi were collected in the form of …

An Empirical Water Quality And Best Management Practice Prioritization Model For Select Arkansas Watersheds, James Mccarty

Graduate Theses and Dissertations

The purpose of this study was to prioritize subwatersheds using water quality data and watershed characteristics. Water quality data was provided through studies by the Arkansas Natural Resources Commission, Beaver Water District, Arkansas Water Resources Center, and publicly available USGS gage data. A total of 114 sites across five HUC-8 watersheds were analyzed, including 12 USGS gages. Watershed characteristic data was retrieved from USGS and Arkansas GeoStore geodatabase repositories. A significant linear relationship between baseflow and stormflow nutrient concentrations was established allowing for the use of baseflow concentrations in the prioritization methodology. Pearson correlation, linear regression, classification and regression tree, …

Mapping Ancient Baldcypress Forests For Conservation At Black River, North Carolina, Jordan Nichole Burns

Graduate Theses and Dissertations

A few ancient baldcypress-bottomland hardwood forests survive across the southeastern United States in a mosaic of remnant old-growth stands left untouched by extensive logging during the early 20th century. Uncut stands in the Southeast that survived centuries of disturbance following European settlement tended to be too senescent and non-commercial to justify logging. Remnant ancient baldcypress forests at Black River, North Carolina, appear to contain the oldest living trees in eastern North America and The Nature Conservancy has protected several of these stands. However, the full extent of ancient bottomland forests along Black River is not known and many valuable tracts …

Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim

Graduate Theses and Dissertations

Isotopes of water (δ2H/δ18O), carbon dioxide (δ13C-CO2), and dissolved inorganic carbon (δ13C-DIC) were used to explore water quality, trace carbon cycling, and quantify recharge sources through mantled karst and into Blowing Spring Cave (BSC). Of the possible sources of contamination in the BSC recharge area, septic-tank effluent was hypothesized to degrade water quality at the spring outlet of BSC because of the dominance of septic tanks for waste treatment, unsuitable topography and soil for septic-tank absorption fields, increased nitrate and chloride concentrations concomitant with increased urbanization, and increased Escherichia coli with discharge. Carbon cycling between the soil and BSC was …

A Pump Monitoring Approach To Irrigation Pumping Plant Performance Testing, William Merritt Mcdougall

Graduate Theses and Dissertations

Traditionally, irrigation pumping plants have been tested using an instantaneous appraoch, which tests performance parameters over a very short time interval. Using this method, the tester measures the necessary work and energy use parameters to calculate the desired pumping plant performance values. The primary limitation of this approach is its inability to determine the season long efficiency of an irrigation pumping plant.

A new approach to evaluating irrigation pumping plant performance is the use of pump monitoring systems which use high frequency, real-time data collection and telemetry to relay information directly from the pump to the user. This method of …

Assessment Of The Predictive Reliability Of A Swat Flow Model And The Evaluation Of Runoff Generation And Bmp Effectiveness In A Shale-Gas Impacted Watershed Using A Modeling Approach, Kwasi Asante

Graduate Theses and Dissertations

In order to ensure a harmonious harness of shale-gas resources while ensuring minimal damage to the environment, it is imperative that studies to conduct to inform various aspects of managing the environment. This includes the development of reliable hydrologic models to inform in decisions concerning water and the environment.

The first objective of this study was to evaluate the predictive reliability of the Soil and Water Assessment Tool (SWAT) model based on respective methods of LULC data classification and data type spatial resolution. Results showed that the high-resolution data classified with object-oriented image method does not provide any significant advantage …

Dammed Arkansas: Early Developments In How Arkansas Came To Be A Dammed State, 1836-1945, Mary Suter

Graduate Theses and Dissertations

The need to manage the rivers of Arkansas has been a driving force in developments that have resulted in dramatic changes to the geographical "face" of Arkansas over the last 200 years. These changes are the creation of man-made lakes throughout the state, where before, there had been none. The many lakes that dot the Ozarks and the Ouachitas were created by dams. There are 1,251 dams over 25 feet in height, or that impound more that 50 acre-feet of water, in Arkansas, and uncounted smaller dams. No matter their size, dams were constructed to manage the rivers and streams …

Assessing The Impacts Of Surface Water Removal For Use In Natural Gas Extraction On A Watershed Level, Carrie Ann Davis

Graduate Theses and Dissertations

In this study, the Soil and Water Assessment Test (SWAT) was used as a tool to predict whether diffuse water removal from the Cadron Creek watershed for use with natural gas development would have an impact on downstream flow within the watershed. Cadron Creek watershed expands across four counties within Arkansas and is located in the Fayetteville Shale Gas region. This region is experiencing significant growth in natural gas development. Successful development of shale gas depends on the identification of what water supplies are available for production without interfering with community and environmental needs. The SWAT model used to evaluate …

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …

Magnitude And Frequency Of Floods For Rural, Unregulated Streams Of Tennessee By L-Moments Method, Hongxiang Yan

Graduate Theses and Dissertations

This study presents a regional frequency analysis of Tennessee using the well-known Bulletin-17B method standardly used in the United States and the relatively new and developing L-Moments methods. Flood frequency characteristics were defined for 416 gaging stations located primarily in rural and lightly developed areas of Tennessee. All the gaging stations have 10 or more years of record through 2006. Using the L-Moments method, the generalized extreme value distribution was identified as the most robust distribution for each of four hydrologic areas. Multiple regression equations were also calculated for estimating the flood frequency of ungaged, unregulated, rural streams in each …

Water Quality Trends And Nutrient Loads For The Watershed Research And Education Center In Northwest Arkansas, 2009-2012, John Metrailer

Graduate Theses and Dissertations

Nitrogen, phosphorus, and sediment transport is a concern for Northwest Arkansas due to high exports through riverine discharge. Urban, agricultural, and pastured watersheds have been associated with increased N, P, and sediment concentrations when compared to forested catchments. The objective of this study was to evaluate discharge and nutrient loads associated with a small urban, agricultural (row crop), wetland influenced, and pasture/farmland sub-catchment within four ephemeral drainages and located at the Watershed Research and Education Center in Fayetteville, AR. Samples were collected during base flow conditions and periodic storm flow conditions from 2009-2012. Flow adjusted concentration trends were used to …

Groundwater Quality Assessment From Domestic Water Wells In The Fayetteville Shale Gas Play Area In Central Arkansas, Anna Marie Nottmeier

Graduate Theses and Dissertations

This study establishes a spatially distributed domestic water well groundwater quality data set, throughout the Fayetteville Shale Gas Play (FSGP) in central Arkansas. The data set facilitates characterization of the geology and groundwater quality across the study area, benefits residents who may have concerns about the potential impacts on their well water quality, and provides a groundwater quality basis to which complaints can be compared and resolved. The assessment included: research of the study area, site reconnaissance, water sampling and collection, interviews with owners of the property, analytical analysis, Quality Assurance and Quality Control, and groundwater data interpretation.

The study …

Synergy Of Alum And Chlorine Dioxide For Curbing Disinfection Byproduct Formation Potential At Central Arkansas Water, Corey W. Granderson

Graduate Theses and Dissertations

Central Arkansas Water (CAW), the water utility for Little Rock, AR, draws their source water from Lake Maumelle and Lake Winona. To curb disinfection byproduct (DBP) formation, CAW has begun retrofitting their two plants to use chlorine dioxide as an alternative primary disinfectant followed by free chlorine secondary disinfection in the distribution system. In this study, fluorescence parallel factor (PARAFAC) analysis was combined with free chlorine simulated distribution system (SDS) tests and DBP formation potential (DBPFP) tests to study the benefit of chlorine dioxide primary disinfection (CDPD) with alum coagulation. Of the DBPs screened, trichloromethane (TCM) was formed in highest …