Social and Behavioral Sciences 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, …

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 …

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 …

Towards Systematic Selection Of Terrain- And Ground Cover-Specific Lidar Filtering Parameters, Vance Green

Graduate Theses and Dissertations

Accurate automated classification of LiDAR point clouds is a well-known problem and proper parameterization of the classification algorithm is essential to creating useful bare-earth terrain models. Parameterization is particularly important in areas characterized by extremely low relief, such as the Little Red River Irrigation Project Area in central Arkansas. In this kind of landscape, analyses such as hydrological flow models are sensitive to small changes in the topography, and therefore prone to errors in the classification of the LiDAR point cloud and the digital elevation models (DEMs) derived from it. Developing effective project-specific parameters requires a high degree of knowledge …

Thermodynamic Modeling Of Aqueous Geochemistry Of Chlorine Salts: Application To Stability And Habitability Of Liquid Brines On Mars, Amira Elsenousy

Graduate Theses and Dissertations

The WCL (Wet Chemistry Lab) instrument on board the Mars’s Phoenix Lander has identified the soluble ionic composition of the soil at the landing site. Two important ions were detected at the landing site; perchlorates (ClO4-) with a concentration of ~ 2.4 wt% and chlorides (Cl-) with a concentration of 0.54 wt%. Between chloride and perchlorate ions three other oxidized ions exist and called chlorine ions: hypochlorite ClO - (ox. state +1), chlorite ClO2- (ox. state +3) and chlorate ClO3- (ox. state +5). These oxidized ions might be existed as intermediate species on the surface of Mars but remained undetected. …

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 …

A Geomechanical Study Of The Mississippian Boone Formation, Karen Nicole Mason Buckland

Graduate Theses and Dissertations

The Boone Formation in northwest Arkansas is a chert-limestone sequence analogous to the subsurface Mississippi Lime reservoir in parts of Oklahoma and Kansas. It has low permeability and produces via horizontal drilling and hydraulic fracturing. The response to stimulation by fracturing is dependent on the quantity of chert in the area. Chert nodules and laterally extensive chert layers in the sequence are variable. Locally, cm- to dm-scale chert bedding is continuous and comprises up to 50% of the outcrop. Elsewhere, the chert is nodular and intermittent.

Samples collected from representative outcrops spanning the thickness and aerial extent of the formation …

Role Of Vegetation And Environmental Characteristics On Slope Stability In Northwest Arkansas, Michael Maguigan

Graduate Theses and Dissertations

Slope failure continues to pose risks to society because knowledge of environmental factors and their interactions are unclear and possibly misunderstood. This misunderstanding leads to generalizations about slope failure susceptibility mapping, despite knowing that slope failures are likely the result of an extensively complex set of interactions among a number of environmental, edaphic, and geomorphic characteristics. Therefore a series of experiments were conducted to investigate the effects of slope, soil texture, vegetation cover, bedrock permeability, and compaction,. A wooden flume with a slope face 1 m wide by 1.5 m long with a 10 cm toe was constructed to contain …

Assessment Of Land Use Suitability Based On Water Erosion Susceptibility In Medium-Sized Urban Areas Of The Metropolitan Region Of Santiago, Central Chile, Roberto Fernandez

Graduate Theses and Dissertations

Urban areas constitute complex spatial entities where biophysical and socioeconomic environments interact through processes that determine the distribution of land use in the territory. Given Chile's variety of landscapes, water erosion, and mass movement, and rapid expansion of its medium-sized cities, straightforward techniques for assessment of land use suitability are essential. Through evaluation of water erosion susceptibility, it is possible to efficiently determine suitability of land use in medium-sized cities and their adjacent environments. The adaptation and application of the Erosion Response Units (ERU) concept (Märker et al., 2001) in the cities of Colina and Melipilla, Metropolitan Region of …

Defining The Regional And Seasonal Climatic Response Of Long Douglas-Fir Tree-Ring Chronologies In Central Mexico, Grant Howard West

Graduate Theses and Dissertations

Problems with instrumental climate data and difficulties arising from the distribution of sensitive, long-term tree-ring chronologies across Mexico's complex terrain have made it difficult to model the climate signal of tree-rings in Mexico. The objective of this research is to utilize the improved long-term, high-resolution, gridded instrumental climate dataset for Mexico recently developed by Zhu and Lettenmaier (2007) to document the climate signal of Douglas-fir in central Mexico. Through correlation analysis between five Douglas-fir tree-ring chronologies created by the University of Arkansas-Fayetteville Tree-Ring Laboratory and Zhu and Lettenmaier's (2007) gridded historical climate dataset, this research aims to define the regional …