Theses and Dissertations - Department of Geography

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    Retrieval of Water Quality Constituents in Inland Waters from Multispectral and Hyperspectral Imagery
    (University of Alabama Libraries, 2020) Min, Xu; Liu, Hongxing; University of Alabama Tuscaloosa
    Remote sensing provides an efficient and effective tool to monitor inland water quality. Various empirical algorithms have been developed to retrieve water quality constituents in inland waters from remotely sensed imagery. The common practice of previous studies has been to calibrate a single empirical model for the entire study area. However, the performance of a single empirical model is often limited for optically complex inland waters. Additionally, traditional empirical models are not spatially or temporally extensible, which impose strict and expensive demand for in situ water truth data during the overpasses of space-borne or airborne sensors. To overcome the limitations of traditional empirical models, my dissertation research focuses on the development of novel remote sensing algorithms for deriving water quality parameters in inland waters from multispectral and hyperspectral imagery. First, I present a geographically adaptive algorithm that addresses the adverse effect of spatial heterogeneity and are able to produce much better water quality parameter estimates than conventional global models. Second, I develop a multi-predictor ensemble model that exploits the comparative advantages of a set of diverse empirical models based on spectral space partitions. The multi-predictor ensemble model has significantly enhanced the water quality prediction accuracy and particularly possessed the desired model extensibility in space and time. Given its strong spatial extensibility, I finally apply the multi-predictor ensemble model to rivers in a large basin for regional water quality analysis. The spatial and temporal extensibility of the multi-predictor ensemble model greatly decreases the operational cost and difficulty, hence facilitating regional scale and long-term water quality monitoring and assessment with remote sensing data.
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    Mangrove Changes Along the Gulf of Mexico and the Caribbean Sea: Remotely Sensed Perspectives on Local-Scale Drivers and Impacts
    (University of Alabama Libraries, 2020) Cissell, Jordan Robert; Steinberg, Michael K.; University of Alabama Tuscaloosa
    The core of this dissertation consists of three local-scale case studies of mangrove forest change in study areas in Belize, Cuba, and Mexico. For each case study, I combined remote sensing, field observations, local knowledge, and scientific literature to document the patterns and processes of mangrove change within the study area. In this dissertation, I analyze these three narratives of mangrove change in concert with one another toward the following three objectives: 1) inform local conservation science and practice within each study area; 2) demonstrate the continued importance of local-scale studies of mangrove change dynamics, and 3) generalize the implications of these three case studies toward a broader understanding of mangrove change trajectories along the Gulf of Mexico and the Caribbean Sea. Toward the first objective, I found that the mangrove forests of Zapata, Cuba, experienced an acute deforestation event with the landfall of Hurricane Michelle in 2001, but areas deforested by the hurricane largely recovered within a decade. In Campeche, Mexico, mangrove decline was driven primarily by urban and agricultural pollution and freshwater flow diversion. In Placencia, Belize, expansion of tourism and aquaculture infrastructure led to the direct deforestation of mangrove forested area and may have helped set the stage for crocodile hybridization. Toward the second objective, I demonstrate that not only do many local-scale products offer more quantitatively accurate depictions of mangrove patterns, but they also provide more nuanced qualitative descriptions of local mangrove change processes. Toward the third objective, my findings suggest that mangrove forests along the Gulf of Mexico and the Caribbean Sea are more resilient to “natural” drivers of deforestation than they are to anthropogenic drivers like land clearance, freshwater flow alteration, and pollution. Furthermore, though they may not always be as immediately apparent as direct deforestation via land clearance or logging, indirect drivers of mangrove deforestation like freshwater flow alteration and pollution can significantly reduce the extent of a given mangrove forest. With direct and indirect anthropogenic drivers of mangrove change increasing in prevalence along regional coastlines, local-scale examinations of mangrove change trajectories will continue to make important contributions to conservation science and practice.
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    Biogeomorphic Impacts of Freshwater Mussels on Reach-Scale Geomorphology in the Sipsey River of Alabama
    (University of Alabama Libraries, 2020) Shafer, Gregory Wayne; Davis, Lisa; University of Alabama Tuscaloosa
    Freshwater mussels are burrowing, filter feeding organisms that were once widespread prior to river regulation but now face extinction or extirpation in many rivers of North America. The lifespan of some species can exceed a century and population densities have the potential to reach one hundred individuals per square meter in some rivers of Alabama. The functional traits of mussels, combined with their long lifespan and ability to occur in high-densities, suggest that they could impact reach-scale sediment processes, involving sediment transport and bank erosion, potentially leading to changes in channel morphology. Few studies, however, have examined ecosystem engineering by mussels and their potential effects on spatio-temporal changes in river morphology. We tested whether four, high-density mussel aggregations (> 14 ind/m2) influenced lateral river migration and bank erosion rates in a 48-km segment located in the Sipsey River of Alabama (USA). We digitized and compared riverbank positions of the study reach on georeferenced historical aerial images from 1965 and images from 2018. Above average rates of lateral migration (>0.2 cm per year) and bank erosion (>33 cm3 per year) occurred at all observed high-density mussel reaches. We observed the presence of mid-channel bars persisting for the duration of the 53-year study period immediately downstream of each high-density mussel location. Additionally, we tested whether mussel population densities can be used to predict locations of reach-scale riverbank erosion. We quantified bank erosion, mussel density, median particle size distribution, and determined bank erosion hazard index (BEHI) scores at 44 transects located within three reaches. We created a stepwise, linear regression model to determine the effect of mussel population density on bank erosion. Mussel density was a stronger predictor (r2= 0.25) of riverbank erosion than most BEHI metrics, including root depth (r2= 0.06) and bank height/bank full (r2= 0.01). The results of this study provide a critical step toward understanding reciprocal relationships between abiotic and biotic systems and new insights into the evolution of channel morphology not previously considered. Future river restoration projects should consider that many organisms, not just abiotic factors, can create biogeomorphic change of river geomorphology.
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    Using Paleoflood Hydrology to Extend Flood Records and Understand Large Floods in South Sauty Creek, Buck's Pocket State Park, AL
    (University of Alabama Libraries, 2020) Corbin, Joni; Davis, Lisa; University of Alabama Tuscaloosa
    In this study, we use multiple paleoflood hydrologic techniques to develop a chronology of flood events that pre-date stream gauge data for South Sauty Creek, a tributary of the Tennessee River in north Alabama. Paleoflood hydrology uses physical evidence of flooding to reconstruct the timing and magnitude of floods that occurred prior to historical and instrumental data. South Sauty’s gorge setting makes the stream highly prone to large floods, which as recently as 2020 resulted in loss of life. Streamflow data only begin in 2011, providing limited data for understanding the large floods generated by this stream. Tree core samples were collected from primarily oak (Quercus) trees with flood impact scars in the riparian zone, and dated using standard dendrochronology techniques. We developed a 247-year flood chronology, with the earliest dated flood in 1758 C.E. Dated tree scar heights correspond to stages associated with flows 34%-65% greater than discharges for the December 2019 high flow, and 17% - 28% greater than the 25-year event that occurred in 2015. The highest tree scars thought to be from the December 2015 flood modeled result in discharges consistent with a 50-200 year flood event. Additionally, sediment entrainment equations based on the Shield’s parameter were used to determine the minimum water height necessary to move the 10 largest imbricated cobbles located in channel adjacent to the tree-sampling site. We use HEC-RAS 5.0.6 to model the discharge associated with the stage that transported the imbricated boulders. Transportation of 80% of the measured cobbles is associated with the largest flows on record or greater, up to 50 times greater than the modeled 2015 event. Future work will expand the data set to include higher tree scars to isolate the dates of larger flood events based on inundation mapping of the floodplain.
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    Exploring the Effects of Urban Sprawl on Low-Income Neighborhoods in Birmingham, AL
    (University of Alabama Libraries, 2021) Blankenship, Jesslyn Cameron; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
    Urban sprawl has led to poorly planned cities that spread out over large distances of land, creating unequal distribution of resources and blocking access to opportunities for low-income residents who remain in the central city (Squires, 2002) . While sprawl does provide the opportunity to live a quiet life outside of the city, the lasting impacts of sprawl are beginning to be seen in inner city communities. Two of these communities are Birmingham, Alabama’s North and East neighborhoods. This study explores the possible causes of Birmingham’s sprawl and residents' opinions of how urban sprawl impacts them socially, economically, and environmentally. Using geographic information system (GIS) technology and a comparison case study approach, it analyzes Birmingham’s history and census tracts within the North and East neighborhoods in order to: determine if low-income households are increasing in fringe suburbs while simultaneously decreasing in the inner city; ascertain whether or not being in close proximity to an economic hub has any effect on household income; establish if property values are an indicator of upward mobility for communities; and confirm the historical causes of the city’s sprawl. In doing so the research was able to determine how residents in North and East Birmingham perceive the potential effects of sprawl. Similar methodology can be applied to other mid-sized American cities hoping to gain more insight into how sprawl affects their citizens.
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    Reconstructing Multi-Century Streamflow Records in the Mobile-Tensaw Delta
    (University of Alabama Libraries, 2021) Jones, Carly; Therrell, Matthew D.; University of Alabama Tuscaloosa
    Across the Southeastern United States (SEUS) growing populations are increasing demand on water resources and infrastructure. Understanding the long-term natural flow regime of rivers is critical to developing accurate models of water level variability needed for appropriate water resource management. Insufficient hydroclimate records fail to accurately capture the frequency of severe droughts or to document long-term monotonic changes in climate, like increased aridity, humidity, or changes in consumption (Crockett et al., 2010). We used new and existing tree-ring chronologies to reconstruct May-August discharge for the Alabama River during the period 900-2011 CE in order to place the period of instrumental flows (since 1931 CE) into historical context.A nested principal components regression model was used to reconstruct streamflow, maximizing the use of chronologies with varying time coverage in the network. The regression model applied utilized the mean index chronology as the predictor for the climate-variable that most influences tree growth at our site. The modeled streamflow estimates indicate that streamflow conditions of the instrumental period do not sufficiently represent the full range of Alabama River flow variability beyond the observational period. Although extreme hydroclimate variability is present in the gage record, the tree-ring record suggests that the intensity and duration of flood and drought events that occurred during the 1500s and 1700s was far more severe. These findings imply that basing future water policy on water availability witnessed during the instrumental period could result in devastating water shortages if droughts as intense as those in the 16th and 18th century were to occur in modern times.
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    Do You Have What I Expect? - Understanding the Gap Between Local Governments' Plans to Mitigate Coastal Hazards and Public Perceptions
    (University of Alabama Libraries, 2021) Cass, Evan Yancey; Shao, Wanyun; University of Alabama Tuscaloosa
    The New Orleans region of Louisiana has been at the front of coastal hazard and climate change research in recent years because of its high social vulnerability, influenced by its location on the Gulf of Mexico, socioeconomic profile, and general location below sea level. Municipal hazard mitigation must be sufficient not only in its coverage of the hazards that pose a threat to the region but also of the hazards that residents of this region are most concerned about. Resident perception of risk is a vital component of social vulnerability and can be utilized by residents and their municipality to increase resiliency against hazards. Because climate change is expected to intensify these threats, it becomes important to ensure that resident perceptions of risk are considered when developing municipal plans to maximize regional resiliency against major events. This research aims to identify a gap in the hazard mitigation process that can be closed to better prepare the community to handle coastal hazards. To achieve this, an online survey is distributed to the New Orleans metropolitan area to determine risk perceptions and expectations of the local government’s action in response to coastal hazards and climate change. Policy analysis is conducted to identify the priorities held by municipal planners in these issues. Through research, it is found that, although there is no gap in the perception of risk and municipal mitigation of current coastal hazards that threaten New Orleans, there is a substantial gap between the municipal approach to climate change mitigation and the worry and expectation of action the residents hold regarding the future effects of climate change on the region. It is recommended that the approach to climate change is reconsidered on a municipal level and that new small-scale personal resiliency incentives are promoted to maximize resiliency toward coastal hazards in the future for New Orleans.
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    Stand Dynamics in a Longleaf Pine Woodland: a Spatial Analysis
    (University of Alabama Libraries, 2021) Phillips, David; Hart, Justin L.; University of Alabama Tuscaloosa
    Global climate change has put an increased focus on enhancing adaptation potential of forest ecosystems. It is hypothesized that structurally complex stands exhibit greater resistance and resilience to stresses. An underutilized component of structural complexity is the spatial arrangement of trees within a stand. In ecosystems where tree species diversity is low, such as longleaf pine (Pinus palustris Mill.) ecosystems, it is critical to maximize spatial heterogeneity to increase structural complexity. These ecosystems cover less than 1 million ha of their previous 37 million ha range and are among the most endangered in the U.S. To increase the effectiveness of management plans within P. palustris ecosystems, we examined spatial patterns within a P. palustris woodland stand within the Oakmulgee Ranger District of the Talladega National Forest, Hale County, Alabama. We specifically asked (1) how were trees distributed in this stand? (2) Are trees clumped, dispersed, or randomly distributed? (3) What spatial relationships exist between mature trees and P. palustris saplings? Using an individuals, clumps, and openings method, we determined most trees existed in clumps beginning at an intertree distance threshold of 3 m. At an intertree distance of 6 m, half of all trees were in clumps of 10 or more. Trees were significantly (p < 0.05) clustered by age and diameter (up to 20 cm diameter at breast height). Pinus palustris saplings were clustered around canopy P. palustris beginning at a distance of 16 m and around Quercus laevis trees beginning at a distance of 7 m. Managers can increase structural complexity (and therefore ecosystem resistance and resilience) by modeling silvicultural prescriptions after the effects of natural disturbance with concrete reference spatial patterns.
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    Global River Delta Morphology Response to Fluvial Sediment Change and Anthropogenic Stress
    (University of Alabama Libraries, 2021) Nanayakkara Munasinghe, Dinuke Sashi; Cohen, Sagy; University of Alabama Tuscaloosa
    River deltas, home to almost half a billion people around the world, are important coastal depositional systems. Valuable natural resources, fertile grounds, and convenient locations for trade have proven deltaic land to become hot spots for urbanization, industrialization, and food production over the last few decades. In this Dissertation the following research questions are investigated: (1) what remote sensing-based algorithms are most efficient in river delta shoreline detection? (2) what changes do we observe of shorelines of individual deltas historically? (3) how is human modification on river delta plains contributing to delta plain erosion? (4) are changes in fluvial sediment flux to the delta are directly linked to decadal changes in delta morphology? A novel multifaceted research approach is used that combines (1) remote sensing analysis of past delta morphology changes, (2) numerical modeling of fluvial sediment fluxes, and (3) GIS/Statistical analysis of shoreline migration rates to answer the intricacies of the aforesaid spatio-temporal questions. This study (a) provides recommendations on different shoreline extraction techniques and make the transfer of knowledge to lesser studied deltaic systems done informatively, (b) provides quantitative understandings of historical shoreline change rates of deltas, (c) quantitative understandings of delta plain erosion from humans having modified delta plains from their pristine conditions, and (d) how shoreline mobility is informed based on riverine fluvial sediment, overall, at a global scale. The outcomes of this study yield several novel insights and scientific advancements of delta morphology changes of the last four decades, and not only transforms our analytical capabilities for studying human influences on river deltas, globally, but also provide a predictive platform that could assist decision makers to make better informed decisions for long-term sustainability of deltas.
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    Application of Deep Learning to Estimate Mean River Cross-Sectional Depth
    (University of Alabama Libraries, 2021) Raney, Arthur Austin; Cohen, Sagy; University of Alabama Tuscaloosa
    Estimates of riverine channel geometry play a vital role in the physical representation of stream networks in models used to predict flood and drought conditions, manage water resources, and increase our knowledge of fluvial conditions under a changing climate. A well established body of literature exists that explains the relationship between channel geometry parameters width, depth, and velocity to instantaneous river discharge using a log-log linear power-law regression. In this study, a state-of-the-art deep learning regression model is presented and compared against the power-law method to evaluate their abilities to estimate cross-sectional mean river depth. Results reveal three key findings, the neural network: (1) decreases RMSE by 22% verse a CONUS scale power-law equation, (2) reduces prediction variance across Strahler stream orders, and (3) generally outperforms regional power-law equations with an average decrease in RMSE of 8.7%. Lastly, a reach-level CONUS dataset of estimated mean river depth is delivered.
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    Accessibility of movement challenged persons to evacuation routes and their earthquake risk perception
    (University of Alabama Libraries, 2021) Bhuiya, Md Musfiqur Rahman; Shao, Wanyun; University of Alabama Tuscaloosa
    This study aims to evaluate the accessibility during earthquake evacuation for movement challenged persons (MCPs), a disable group highly vulnerable to earthquake, and explores their risk perception in the context of megacity Dhaka, Bangladesh. As there is no accessibility measure to determine accessibility of a network of MCPs integrating physical impedance faced by them in their movement, this study has modified Link to Node Ratio calculate the accessibility of MCPs with consideration of physical impedance and applied it determine the accessibility of MCPs to evacuation routes of 13 wards of Dhaka. Study of accessibility of MCPs during evacuation reveals that 6 wards have poor overall accessibilities while 3 wards have relatively satisfactory conditions of overall accessibility and 4 wards have relatively good accessibilities but fall short of satisfactory conditions. The study reveals that MCPs who are more aged and have more severe level of disability perceive accessibilities of evacuation network, indoor floor surface and entrance gate to be lower. Moreover, male and better educated MCPs is found to perceive accessibilities of indoor floor surface and entrance gate to be higher. Age, income, structure, having experienced an earthquake earlier, mass media as a source of information on earthquake training is found to contribute to perceiving higher level of earthquake risk (as a whole). MCPs who have participated in the training program is found to know what they should do in the advent of an earthquake irrespective of being outside or inside of the home. The study reveals lack of accessibility in training centers and lack of distribution of information of training programs as key reasons behind MCPs not participating in the training.
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    A study of infrastructural connectivity on a college campus: the case of the University of Alabama
    (University of Alabama Libraries, 2021) Schnarre, Emily L.; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
    As the University of Alabama and the City of Tuscaloosa continue to undergo unprecedented growth, more students than ever need to commute to campus. While most students choose to drive to campus, this places stress on the University’s parking lots and development plans. In an attempt to combat that stress, the multimodal network infrastructure, was evaluated to identify the overall connectivity for student commuting. This evaluation was completed by using graph theory applications to gauge to overall connectivity of the sidewalk, bike lane, and bus route networks available to students at the University of Alabama. Through GIS mapping, relationships between these networks were identified, as well as gaps in these networks. Along with these graph theory metrics, a survey of student’s commuting patterns was performed to identify how students travel to campus and their overall familiarity with the alternative transportation networks. Together, this data was compiled to identify areas in which connectivity is limiting a student’s ability to commute to campus, either due to gaps in the network or lack of awareness of the network. These results were used to create policy recommendations which sought to improve connectivity metrics and overall mobility for students at the University of Alabama in an effort to combat the recent unprecedented growth.
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    A review and case study of multiple interacting disturbances in forest ecosystems
    (University of Alabama Libraries, 2021) Kleinman, Jonathan Samuel; Hart, Justin L.; University of Alabama Tuscaloosa
    Strategies to enhance ecosystem resilience are increasingly needed in forest management plans. Natural and managed disturbances that alter ecosystem resilience to other perturbations are called compound disturbances. This dissertation first synthesized the literature on compound disturbances in forest ecosystems. I used a systematic review to catalogue case studies of compound forest disturbances and identify trends in the types, timing, environmental settings, and ecological consequences of each disturbance combination. The review emphasized that the detection of positive, negative, and neutral disturbance impacts on ecosystem resilience were often contingent on which response variables were used to monitor forest recovery. To illustrate and investigate this and other key concepts described in the review, I then examined a combination of wind disturbance, salvage logging, and prescribed fire in the Alabama Fall Line Hills. A range of woody plant, ground flora, and ground surface material metrics were collected before and after prescribed fire in Pinus palustris Mill. woodlands differentially impacted by an EF3 tornado and salvage logging. In support of the review, salvage logging and prescribed fire had different effects on post-wind disturbance recovery depending on which response variables were assessed. Pinus palustris saplings exhibited the greatest densities in salvage-logged sites and were more resistant to prescribed fire than most other sapling species. This indicated that recovery toward P. palustris canopy dominance was not negatively affected by salvage logging and was enhanced by prescribed fire. Ground flora diversity and community dissimilarity, however, were reduced in salvage-logged sites before and after prescribed fire. Nonetheless, prescribed fire did impose some consistent selective pressures on understory plants with common life-history strategies. Overall, this dissertation supported the use of prescribed fire to promote P. palustris woodland recovery. Leaving some wind-disturbed zones unlogged was also recommended to support ground flora resilience. Moving forward, a diversity of response variables should be measured to achieve comprehensive assessments of disturbance effects on ecosystem resilience.
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    Classifying land use/land cover change over time within the watershed boundary of keenjhar lake using supervised, unsupervised, and hybrid classification methods
    (University of Alabama Libraries, 2021) Henry, Katherine Rae; Han, Luoheng; University of Alabama Tuscaloosa
    This study determined the change of land use/land cover over time within the watershed boundary of Keenjhar Lake through the usage of remote sensing thematic classification methods, and, assessed if the changes occurring related to statements made in other studies about wetland and biodiversity decline. The three thematic classification methods utilized and compared in this study were the supervised, unsupervised, and hybrid classifications. Due to its higher overall accuracy, the supervised classification method was chosen to classify the March 07, 2020 Landsat 8 image and for post classifications from 1997 to 2002, 2002 to 2008, and 2002 to 2020. The results of this study did not support the hypotheses that there was a decline in wetland percent cover over time and that the hybrid classification was more accurate in comparison to other algorithms. The results did support the hypothesis that there was an increase in urban/agricultural land over time. The utilization of remote sensing in this study to assess land use/land cover did not indicate there was a decline in wetland size due to the 1998-2002 drought and other more recent droughts. For future studies, finer spatial resolution imagery is needed to further break down the land use/land cover classes and to determine minor changes that were not recognized in this study.
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    Digital dumping ground in Ghana: a study on potential impacts of e-waste in Agbogbloshie
    (University of Alabama Libraries, 2021) Chan, Amber Michelle; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
    Despite the growing use of electronic products, waste recycling efforts are not expanding at a proportional pace, and places in the Global South like Ghana are left with toxic waste sites like the one at Agbogbloshie that are arguably an indirect result of Western consumer capitalism. In spite of significant international attention, the e-waste trade in Agbogbloshie continues to persist, prompting the need for a more comprehensive look at the potential impacts of its continuation on the environment and human health. By examining the potential impacts of the e-waste trade in Agbogbloshie through a critical geography lens, it is hoped that a more nuanced account can assist restoration efforts that minimize harm to the communities that live in and rely on the e-waste trade. This thesis presents an analysis of seven video interviews specific to different careers concerning e-waste in Agbogbloshie with a particular emphasis on the identification of the potential impacts of the e-waste trade. Utilizing transcribed interview footage alongside existing literature and applying qualitative analysis techniques, several conclusions were reached based on the main thematic points identified: workers know e-waste is harmful to their health, e-waste is a significant source of income for many people, the disconnect between the formal and informal sectors makes restoration efforts difficult to coordinate, and the future of skilled workers is in jeopardy. Although far from comprehensive given the small sample size, these interviews lend a great deal of insight into the potential human and environmental impacts of electronic waste in Agbogbloshie.
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    Developing a holistic-empirical methodology for identifying areas of potential environmental justice concerns: a case study of Jefferson County, Alabama
    (University of Alabama Libraries, 2020) Jack, Katie; LaFevor, Matthew; University of Alabama Tuscaloosa
    Environmental justice (EJ) – the belief that everyone, regardless of race, income, or national origin, deserves to live and work in a healthy environment and to be included in decision making processes regarding their environment – has gained an increased presence within popular culture over the past several decades, yet many low-income and minority populations still experience greater environmental burdens than other communities. Despite a broad awareness that environmental injustice proliferates in the United States and throughout the world, and despite numerous attempts by government agencies and various academics, there is not a clear methodology for identifying areas of potential concern in the EJ literature. With pollution data from the Toxic Release Inventory (TRI) and demographic data at the census tract level from the Census Bureau on median household income and minority populations, this thesis seeks to fill this gap, by creating a model that recognizes sites of potential environmental injustice using Jefferson County, Alabama, as an example. By utilizing Geographic Information System (GIS) tools and statistical software, relationships between the amount of – and exposure to – pollution and median household income and minority population percentage were either confirmed or rejected. A field survey was also conducted in the three census tracts in Jefferson County with the most pollution to see if any other common factors associated with environmental injustice such as lack of access to healthy foods and medical care were observable. In Jefferson County, minority population percentage, both on its own and in conjunction with median household income, is a weak to moderate but statistically significant predictor of exposure to pollution, and various combinations of other factors associated with environmental injustice were observed in each of the three census tracts analyzed. While this study did not yield definitive results that there are specific instances of environmental injustice in Jefferson County, Alabama, the synthesis of results from the numerous phases of investigation indicates areas of potential concern and that further research needs to be done to both establish inequitable environmental conditions and to further calibrate the model.
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    Self-caught fish consumption and methylmercury advisories in Tuscaloosa County, Alabama
    (University of Alabama Libraries, 2020) Dugat, Joshua; Steinberg, Michael K.; University of Alabama Tuscaloosa
    Methylmercury is a naturally occurring toxin, capable of bioaccumulation within aquatic ecosystems. Diets high in fish with elevated levels of methylmercury can lead to neurological impairments, especially in young children. Low-income and minority anglers have been found to consume higher rates of self-caught fish than individuals from other demographic groups, and may incur a higher risk of methylmercury-related hazards. This study uses creel surveys and data from the Alabama Department of Environmental Management’s Fish Tissue Monitoring Program to identify trends in consumption, advisory awareness, and methylmercury concentration across two demographically representative sites in Tuscaloosa County, Alabama. Surveys suggest that anglers reporting lower household income reported higher rates of self-caught fish consumption. African American anglers reported consuming a significantly higher rate of self-caught fish than white anglers (mean calculated consumption = 67.17 g/day and 23.51 g/day; p = 0.004). Anglers indicating an awareness of consumption advisories reported consuming self-caught fish at a nominally lower rate than anglers who indicated being unaware of advisories. Fish tissue data indicates higher levels of methylmercury in largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus) near the Lake Tuscaloosa study site where current advisories are issued. Environmental conditions seem to support greater rates of mercury methylation and bioaccumulation at the site with existing advisories. Still, there is a perception amongst some anglers that fish from the Black Warrior River – where no advisories are issued – are more dangerous to eat than those in Lake Tuscaloosa. These reactions may call into question the quality and efficacy of the current advisory system. Misinformation surrounding methylmercury’s presence and health consequences suggest greater public understanding may increase the effectiveness of fish consumption advisories. While the study focused on consumption by adult anglers, future research may also seek to determine consumption trends in more vulnerable populations: children, pregnant and nursing women, and women who may become pregnant. This study contributes to a body of research that seeks site-specific data to create a more comprehensive understanding of risks related to fish consumption. It also exposes the gradations of advisory effectiveness, risk perception, and of threats to wellness anglers face beyond those toxins fish contain.
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    Social-ecological systems of sheep ranching, recreation, and large carnivores on multiple-use U.S. public lands
    (University of Alabama Libraries, 2020) Holland-Levine, Anna Crystal; Magliocca, Nicholas R.; University of Alabama Tuscaloosa
    The multiple use policy on over 441 million acres of public lands mandates “the management of the public lands and their various resource values so that they are utilized in the combination that will best meet the present and future needs of the American people.” Most contentious among these uses has been the debate surrounding the 257 million acres of public lands used for ranching in the American West. Conflicts over rangeland access and management have recently been heightened by the reintroduction and recovery of large carnivores and the rise of recreational use. Spatial and temporal partitioning have been shown to minimize conflicts but the geospatial information that could model, predict, and allow the geographically specific management of conflict in a multiple-use system is a lacuna in the literature. This knowledge gap, and the causes and solutions of conflict, can best be understood in the broader context of their social dimensions. I use the social-ecological systems framework (SESF) to create a contextualized causal map of flows between sheep ranching, large carnivore conservation, and recreation on public lands in an Inter-mountain West community. Using data from sheep fitted with GPS trackers to quantitatively support ethnographic information, I spatialize the SES with a partial suitability model for sheep grazing. This is a step toward a geographical tool that combines models of carnivore occupancy and recreational use to predict and prevent conflict between multiple uses. In combination with an understanding of the SES, this tool can increase adaptive capacity in resource management by enabling quantitative, spatially explicit social and ecological cost-benefit analyses at appropriate scales.
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    Influence of coarse woody debris on seedlings and saplings in a Pinus palustris woodland
    (University of Alabama Libraries, 2020) Logan, Alexandra; Hart, Justin L.; University of Alabama Tuscaloosa
    Coarse woody debris (CWD) has beneficial effects on plant growth and establishment. Longleaf pine (Pinus palustris Mill.) stands support relatively low amounts of CWD — 2 to 30 m3 ha-1. In April 2011, an EF3 tornado passed through the Oakmulgee Ranger District of the Talladega National Forest in the Fall Line Hills of Alabama. This disturbance resulted in the large addition of CWD to a longleaf pine woodland, and a rare opportunity to analyze how CWD can influence a managed, pine woodland. The goal of this study was to examine the effect of CWD on woody plant richness, density, and growth rate (quantified by height) in a longleaf pine woodland that experienced a catastrophic wind disturbance. A total of three 1 m2 quadrats were established against either side of a piece of CWD (> 3 m in length and ≥ 10 cm in diameter). Another quadrat was established at least 3 m away from the focal CWD piece. For each plot, the presence and height of every woody plant (< 5 cm dbh) were recorded. Sapling density, oak and hickory density, and organic matter were all found to be significantly higher in quadrats adjacent to CWD than away (all p < 0.05). There was also a significant relationship between CWD decay class and average plant height, richness, density, and organic matter (all p < 0.05). Results from this study help to inform managers about the ecological functions of CWD in longleaf pine systems and other pine woodlands.
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    A geographic interpretation of the causes underlying urban growth and distribution in Alabama, 1820 – 2010
    (University of Alabama Libraries, 2020) Fries, Alexander Christopher; Weber, Joe; University of Alabama Tuscaloosa
    Urbanization in Alabama has been driven and influenced by a number of factors over the course of the state’s history. Examined from a geographic standpoint, the sizes and spatial distributions of Alabama’s cities have been chiefly driven at different times by access to the state’s navigable waterways; proximity to its major cotton-cultivating regions; access to significant railroad infrastructure; proximity to the state’s major coal and iron ore deposits; access to significant highway infrastructure; proximity to various “institutional industries” (defined here as the combination of county seats of government, public universities, permanent military installations, and the site of the state capital); and the process of suburbanization. This study employs qualitative data-collection and quantitative analysis methods to determine the possibility of modeling the explanatory power of these variables relative to the populations of the state’s twenty largest cities in each decade since 1820 in a manner that complements and aligns with the prior literature on the subject using multiple linear regression. The resulting models are able to successfully capture a single statistically-significant geographic variable with great accuracy, although the results are also somewhat more mixed when examining possible secondary and tertiary predictors of city population. The research serves as a stepping stone towards developing a statistical means of analyzing and understanding the impacts of various geographic factors on urban population that is both adaptable to other regions of the world and is able to produce outputs that are relatively easy to map and visualize.