Social and Behavioral Sciences Commons^™

Pattern Exploration And Event Detection From Geo-Tagged Tweets, Yugian Huang

Open Access Theses

Twitter is one of the most famous social networking services in the world. With 313 million monthly active users, Twitter can produce around 6,000 tweets per second, which corresponds to around 500 million tweets per day and around 200 billion tweets per year. Besides being a successful company, Twitter provides a great opportunity to scientists from various disciplines. Twitter allows users to tweet with a location tag, which enables the connection of virtual networks to the events happening in real life. Because of the massive amount of valuable geographic information, location-based services, targeted advertising, and social network studies could benefit …

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 …

Synthetic Aperture Radar Interferometry Analysis Of Ground Deformation Within The Coso Geothermal Site, California, Erik Vaughn Brawner

Graduate Theses and Dissertations

Earth’s surface movement may cause as a potential hazard to infrastructure and people. Associated earthquake hazards pose a potential side effect of geothermal activity. Modern remote sensing techniques known as Interferometric Synthetic Aperture Radar (InSAR) can measure surface change with a high degree of precision to mm scale movements. Previous work has identified a deformation anomaly within the Coso Geothermal site in eastern California. Surface changes have not been analyzed since the 1990s, allowing a decade of geothermal production impact to occur since previously assessed. In this study, InSAR data was acquired and analyzed between the years 2005 and 2010. …

Trade And Transport In Late Roman Syria, Christopher Wade Fletcher

Graduate Theses and Dissertations

Despite the relative notoriety and miraculous level of preservation of the Dead Cities of Syria, fundamental questions of economic and subsistence viability remain unanswered. In the 1950s Georges Tchalenko theorized that these sites relied on intensive olive monoculture to mass export olive oil to urban centers. Later excavations discovered widespread cultivation of grains, fruit, and beans which directly contradicted Tchalenko’s assertion of sole reliance on oleoculture. However, innumerable olive presses in and around the Dead Cities still speak to a strong tradition of olive production. This thesis tests the logistical viability of olive oil transportation from the Dead Cities to …

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 …

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 …

Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones

Graduate Theses and Dissertations

A digital geologic map of the Rockhouse quadrangle, Carroll and Madison counties, Arkansas, was created on a 1:24,000 scale using ArcMap 10 and Photoshop CS4. The data obtained in the field are digitized onto the United States Geological Survey (USGS) digital raster graphic (DRG) of the Rockhouse quadrangle. The geology in the Rockhouse quadrangle consist entirely of sedimentary rocks that are Paleozoic ranging from Lower Ordovician to Mississippian in age. The Ordovician System is represented by the Cotter, Powell, Everton, and St. Peter Formations. The Cotter and Powell are the prominent bluff forming units throughout the quadrangle and along the …

Manifold Learning Based Spectral Unmixing Of Hyperspectral Remote Sensing Data, Jun-Hwa Chi

Open Access Dissertations

Nonlinear mixing effects inherent in hyperspectral data are not properly represented in linear spectral unmixing models. Although direct nonlinear unmixing models provide capability to capture nonlinear phenomena, they are difficult to formulate and the results are not always generalizable. Manifold learning based spectral unmixing accommodates nonlinearity in the data in the feature extraction stage followed by linear mixing, thereby incorporating some characteristics of nonlinearity while retaining advantages of linear unmixing approaches. Since endmember selection is critical to successful spectral unmixing, it is important to select proper endmembers from the manifold space. However, excessive computational burden hinders development of manifolds for …

Classification Of Satellite Time Series-Derived Land Surface Phenology Focused On The Northern Fertile Crescent, Brian Embree Bunker

Graduate Theses and Dissertations

Land surface phenology describes events in a seasonal vegetation cycle and can be used in a variety of applications from predicting onset of future drought conditions, to revealing potential limits of historical dry farming, to guiding more accurate dating of archeological sites. Traditional methods of monitoring vegetation phenology use data collected in situ. However, vegetation health indices derived from satellite remote sensor data, such as the normalized difference vegetation index (NDVI), have been used as proxy for vegetation phenology due to their repeated acquisition and broad area coverage. Land surface phenology is accessible in the NDVI satellite record when images …

Agricultural Production And Stability Of Settlement Systems In Upper Mesopotamia During The Early Bronze Age (Third Millennium Bce), Tuna Kalayci

Graduate Theses and Dissertations

This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system.

The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production …

Landscape Epidemiology And Machine Learning: A Geospatial Approach To Modeling West Nile Virus Risk In The United States, Sean Gregory Young

Graduate Theses and Dissertations

The complex interactions between human health and the physical landscape and environment have been recognized, if not fully understood, since the ancient Greeks. Landscape epidemiology, sometimes called spatial epidemiology, is a sub-discipline of medical geography that uses environmental conditions as explanatory variables in the study of disease or other health phenomena. This theory suggests that pathogenic organisms (whether germs or larger vector and host species) are subject to environmental conditions that can be observed on the landscape, and by identifying where such organisms are likely to exist, areas at greatest risk of the disease can be derived. Machine learning is …

Mapping Xenophobic Violence In South Africa: Modeling Spatial Relationships Between Group Grievances And Opportunities To Measure The Propensity For Xenophobic Violence, Eric Holder

Graduate Theses and Dissertations

Xenophobia can be defined as the hatred or fear of foreigners or strangers or of their politics or culture (Ngwane et al., 2008). This sentiment reached its tipping point in urban areas across the Republic of South Africa in May 2008 when mass, widespread and systematic attacks against African non-nationals took place across the country. Although previous research agrees on who played the various roles during this crisis event (Everatt, 2010), little research has been carried out to create a predictive model to assess where future violence could occur based on a set of conflict indicators. The purpose of this …

Kites For Low Cost Near Earth Aerial Archaeological Photography, Robert Joseph Brandon

Graduate Theses and Dissertations

This thesis presents an overview of kite aerial photography (KAP) as a platform for archaeologists to acquire time sensitive unmanned near earth aerial photography for archaeological research. The methods and tools reviewed in this thesis are limited to those that make this technology accessible to the typical poorly funded archaeologists working in remote locations. The KAP methods detailed here have a low start up cost, are easy to transport, and a can be easily learned by archaeologists. The goal of this thesis is to promote KAP as a significant and regularly utilized tool for archaeological projects.

Navigation And Accessibility For Persons With Disabilities: An Anthropological Study Using Gis On The University Of Arkansas Campus, Deborah Jean Raiees-Dana

Graduate Theses and Dissertations

The University of Arkansas was founded in 1871 on the top of a hill overlooking the Ozark Mountains, resulting in a campus that has steep slopes and numerous historical buildings that were not designed with ADA regulations in mind. This makes getting around campus especially difficult for students with limited mobility, and no campus maps exist that include handicapped accessibility features to help navigate the terrain and limited parking options. This study examines this issue using a holistic approach that explores cultural and technological factors to produce a map of the Historic Core District of campus.

Geographical Information Systems enable …

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 …

An Alternate Approach To Ecosystem Mapping: Fusing Orthophotography With Landsat Etm+ Data For A Object-Based Classification, South Eastern Arkansas., David Mcfee

Graduate Theses and Dissertations

Maintaining representative sampling of biologically rich and rare ecosystems has become an important means to preventing biodiversity loss. A limitation in indentifying and quantifying ecosystems is the cost of obtaining high resolution imagery necessary for a high resolution land cover assessment. This research shows how free, different resolution imagery (orthoimages and LANDSAT ETM+) could be combined to produce a hybrid dataset with enhanced spectral, spectral and temporal properties, and processed to obtain a object-based classification of land cover of bottomland and pine hardwood forest in south eastern Arkansas. Three classification techniques were evaluated: 1) a human derived, rule based method, …

Identifying Optimal Cellulosic Biomass Feedstock Supply Areas For Potential Biorefineries In Arkansas, Mark Cooper

Graduate Theses and Dissertations

In February 2010, the U.S. Environmental Protection Agency released the revised Renewable Fuel Standard (RFS2), mandating at least 36 billion gallons of renewable fuels to be produced annually in America, and blended into all on/off road, locomotive, and marine gasoline and diesel by the year 2022. America's existing biorefineries fall significantly short of being able to meet this mandate, resulting in the need for rapid expansion in the near future if this goal is to be met. The state of Arkansas has abundant resources to offer the renewable energy industry, if properly utilized. The goal of this thesis is to …

Analyzing Spring Freeze Impacts On Deciduous Forest Productivity Using Modis Satellite Imagery, Karl Lintvedt

Graduate Theses and Dissertations

The impacts of an April 2007 spring freeze event on the productivity of deciduous broadleaf forest were analyzed using geographic information system (GIS) tools. Forest productivity was modeled using the Enhanced Vegetation Index (EVI), as recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor. Measures of spatial autocorrelation were used to quantify the degree of spatial congruence between a map depicting the severity of the freeze event, and maps modeling forest productivity throughout the year. The results show a geographic correlation between the unseasonably low minimum temperatures sustained during the freeze and the unusually low forest productivity that followed. …