Browsing by Subject "GIS"
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Item Open Access A Comprehensive Assessment of Red Wolf Reintroduction Sites(2018-04-24) O'Neal, ShaneThe red wolf (Canis rufus) is the world’s rarest wild canid, with fewer than 60 wolves living in the wild, and likely even fewer than 40. After being declared extinct in the wild in 1980, the wolf was reintroduced to Alligator River National Wildlife Refuge in North Carolina in 1987 and successfully established itself, with the small initial population growing to 150 within two decades. Recent increases in mortality have reduced the wolf’s numbers to their current low levels, and the Fish and Wildlife Service now faces the difficult decision of where else to reintroduce the red wolf within its historic range. This Masters Project is an attempt to analyze the current landscape of the Southeast from both an ecological and sociological perspective to determine the best possible places for red wolves to successfully establish a new population. I first conducted a literature review to identify key variables that affect the suitability of an area and found five such factors: available habitat, available prey, concentrations of livestock, recreational hunters, and the age of local residents. The reintroduction effort has to begin on federally owned and protected land, and so I next set out to select a suite of potential sites for the reintroduction to take place, establishing a list of 21 such locations. The relationship between all of the variables I considered is complex, so to properly weight them against each other I surveyed 14 experts in red wolf biology and management. I received responses from 10 of the experts and used this information to construct models in ArcGIS to determine the overall suitability of a site. After assembling a Weighted Sum model based on available data and calculating descriptive statistics, the sites all received a suitability score. The highest-scoring sites were Croatan National Forest in North Carolina and Okefenokee National Wildlife Refuge in Georgia. Fish and Wildlife should focus future reintroduction efforts on these locations, which strike the best available balance between suitable ecology and low chances of human-wolf conflict.Item Open Access A Geospatial Analysis of Pathways for Carbon Sequestration(2008-04-25T15:01:19Z) Frankel, AnnaThe 2007 IPCC report detailed the warming of the earth is unmistakable and is most likely due to anthropogenic greenhouse gas (GHG) emissions. The earth’s natural processes are unable to reabsorb GHGs at the rate at which they are being emitted, subsequently increasing climate temperatures and affecting ecosystems and populations around the world. Carbon capture and sequestration technologies are a possible mitigating solution to preventing emission of GHGs into the atmosphere. This analysis takes a geospatial approach to understanding the interconnecting pathways between carbon sources and sequestration sinks for future CO2 pipeline networks in the United States. Using geographical information systems (GIS), engineering, environmental, and social factors important to the pipeline siting process are evaluated and combined to make a geographical cost surface. A least cost path sensitivity analysis was performed to ensure confidence in the suitability of the cost surface. The final CO2 pipeline cost surface investigates the spatial dynamics of carbon sequestration and the relative cost elements that will influence the pipeline network. Utilities and other organizations can use the cost surface in future projects as an analytical tool showing areas of relative high and low pipeline costs. A scenario analysis was performed using the final CO2 cost surface as a tool to examine future spatial configurations of sequestration sites. The analysis found that a sequestration scenario with multiple points of CO2 injection across the United States would yield the lowest total relative costs for a national pipeline network.Item Open Access A Geospatial Approach to Siting Wind Right in the Southeast(2021-04-29) Feng, Xueying; Li, ShawnWhile installed wind turbine capacity continues to increase in the United States, a noticeable void exists in the Southeast due to a combination of poor wind resources, competing energy sources, and political opposition. As manufacturers develop turbines with a higher hub height to harness faster and smoother wind resources, many, including The Nature Conservancy, anticipate significant wind development in the Southeast. The identification of low environmental impact areas will not only lower the risk of project development but will also enable the identification of priority areas for transmission and distribution infrastructure. To capitalize on the opportunity to site wind right from the beginning, this study uses a GIS-based exclusion category approach to identify areas where installed wind power capacity is least likely to disrupt wildlife and sensitive habitats. The geospatial model creates maps where environmental and technical areas that are unsuitable for wind farms are removed. The model considers a sequence of five categories of land exclusion criteria. The resulting geospatial product suggests that even after removing sizable areas from consideration, there is significant land for wind development to meet the energy and climate needs of the Southeast region.Item Open Access A GIS Tool Prioritizing Dams for Removal within the State of North Carolina(2012-04-27) Hoenke, KathleenA GIS tool for prioritizing removal of dams based on ecological and social metrics is presented. The Barrier Prioritization Tool uses a hierarchical decision making framework that entails identification of an objective, criteria of qualities that meet that objective, and measurable indicators to quantify if criteria is met. Here the primary objective is to identify the best dams to remove. Criteria include good habitat connectivity, good water quality connectivity and connectivity of stream miles while avoiding social conflict, improving flow downstream, and improving safety. Sensitivity of rankings to habitat indicators used indicates that indicators of habitat quality overlap. Following the construction of the Barrier Prioritization Tool, three prioritization scenarios are conducted for American Rivers; one prioritization includes social and safety criteria, another includes only ecological criteria, and the third is a prioritization specific to anadromous fish. All three of these prioritization scenarios identify dams within the top 20 ranked dams that are currently classified as pre-identified potential dam-removal projects, indicating that the tool is performing as intended. Dam removal has proven to be an effective mechanism of quickly restoring in-stream habitat for lotic species through connecting fragmented river networks and returning the system to a free flowing state. By aiding in the dam removal project identification process, this tool makes the restoration of streams through dam removal more efficient. In the future, this tool will be used by American Rivers and their colleagues to run other prioritizations of the tool while experimenting with different indicator and criteria weights in order to find more potential projects for removal.Item Open Access An Information Systems Strategy for the Environmental Conservation Community(2008-04-25T20:55:48Z) Barker, KristinAs the cause of environmental conservation emerges as a global priority, the need for a practical information systems strategy shared among conservation organizations becomes imperative. Historically, researchers and practitioners in conservation have met their own information management and analysis needs with inevitable variation in methodology, semantics, data formats and quality. Consequently, conservation organizations have been unable to systematically assess conditions and set informed priorities at various scales, measure performance of their projects and improve practices through adaptive management. Moreover, the demands on conservation are changing such that the bottom-up approach to information systems will become an increasing constraint to effective environmental problem solving. Where we have historically focused on the protection of “important” places and species and more recently “biodiversity,” conservation is moving to a systems view, specifically ecosystem-based management, where relationships and process are as important as the individual elements. In parallel, awareness of the human dependency on functioning natural systems is on the rise and with it the need to explicitly value ecosystem services and inform tradeoffs. Climate change requires conservation to develop dynamic adaptation scenarios at multiple spatial and temporal scales. Finally, the business of conservation is under increased pressure to account for its spending and objectively measure outcomes of its strategies. All of these changes translate to growing, not shrinking, demands on information and information systems. In response to these challenges, this research presents an information systems strategy for the environmental conservation community. It proposes the development of a distributed systems infrastructure with end-user tools and shared services that support standardized datasets. Key strategies include removing the barriers to information sharing, providing valuable tools to data producers and directly supporting heterogeneity in conservation datasets. The strategy concludes with a call for high-level management involvement in information systems strategy and collaborative investment in implementation by the conservation community, partners in government and donors. Without these steps, conservation as an industry may find itself ill-equipped to meet the changing needs of people and nature.Item Open Access An Inventory of the Wetlands Impacted by the U.S. Navy's Proposed OLF Site in Gates County, North Carolina(2009-04-24T12:57:54Z) Allie, AnnaThe US Navy has proposed construction of an Outlying Landing Field (OLF) for carrier-landing practice, at one of five potential sites in North Carolina and Virginia. The proposed Sandbanks site in Gates County, NC is opposed by the Citizens Against OLF, who asked the Duke Environmental Law and Policy Clinic to evaluate possible damages to the area by drafting an Environmental Impact Statement. This project will contribute to that EIS by evaluating the site’s hydrology and wetlands using GIS analysis. Results of examinations of the wetlands’ ecosystem services indicate large areas of important wetlands on and near the site. The individual results (buffering capacity, runoff estimates, and habitat quality) are integrated into a single product that can be compared to the North Carolina Coastal Region Evaluation of Wetland Significance (NC CREWS). This comparison shows a larger area of high significance wetlands in the NC CREWS rating due to depth of the analysis, among other factors. There is ample evidence of high wetland significance at the Gates County site.Item Open Access AN UPDATED ANALYSIS OF PRIORITY LANDS FOR CONSERVATION IN THE ELLERBE CREEK WATERSHED(2022-04-21) Shapiro, Shana; Keller, SashaTraditionally, conservation organizations sought to protect the most pristine land from the pressures of conversion and degradation. The conserved lands were identified by their inherent ecological value such as biodiversity or their proximity to bodies of water. The legacy of protecting important ecological areas often overlooked natural spaces in urban areas because they were near developed areas or were themselves developed and required restoration. The contrast between urban and rural land protection led to more conservation outside urban areas and made the spaces and ecosystem services even more difficult to access. Our client, the Ellerbe Creek Watershed Association (ECWA), is a Durham nonprofit organization looking to contend with the conservation of natural spaces in an urban area in a more equitable way. Founded in 1999, ECWA was born from the realization that invasive species were proliferating in Durham. Through the use of conservation easements, fee simple acquisition, and transfers ECWA now owns and manages 450 acres of conserved lands. They work to protect and improve the Ellerbe Creek with the help of volunteers, and they are working to expand their efforts with equity and environmental justice at the forefront. ECWA first partnered with The Nicholas School to prioritize conservation lands in 2012. Yacobson (2013) constructed ECWA’s first geospatial tool to identify target areas, and our project works to update and reconstruct the model with both ecological and equity perspectives. Following a multi-criteria decision analysis framework, we constructed an adjustable model that will allow ECWA to find the most opportune areas for conservation according to their needs. Additionally, we emphasized equity as a core component of the analysis. Like many land trusts, ECWA has limited time and resources to devote to geospatial expertise. A driving goal for the project was to create a usable tool for ECWA’s limited GIS infrastructure. We created an easy-to-access, standardized, and easy-to-update model that includes datasets that are reliably funded and managed. Additionally, we synchronized our data with regional conservation efforts and built on established research in the Durham area. In collaboration with ECWA, we decided to base the prioritization on four main themes: (1) Water quality, (2) Habitat, (3) Equity, and (4) Accessibility potential. We combined the criteria from each theme in both equally weighted and adjusted weighting scenarios, resulting in different parcel conservation score rankings. Overall, the prioritization tool fulfills the need for a usable and adjustable tool that identifies the most opportune parcels for conservation. We provide maps and tables of the contributing criteria scores as well as the overall scores for different weighting scenarios. We find that when equity or accessibility are emphasized and weighted more heavily in the model, the resulting parcels with the highest conservation values are in distinctly different locations from model results where water quality or habitat are weighed more heavily. When equity and accessibility are weighed slightly higher than water quality or habitat, the parcels with the highest conservation value are located in more urban areas with lower socioeconomic status. The differences in conservation value based on the weighting scheme reflect how the priorities of a conservation organization can affect which parcels are most sought for conservation. The results can then inform conservation planning, project evaluation, educational outreach, and communication efforts for ECWA as they continue their work to protect the Ellerbe Creek watershed’s quality and provide more equitable access to green space.Item Open Access Applying GIS to the Logistics of Material Transportation for Constructing the Baths of Caracalla in Rome(2017) Manning, Stephanie MarionThe purpose of this thesis is to visualize the economic system (supply, production, and transportation) and the logistics of the movement of marble in the Roman Empire in an effort to better understand the larger system of material movement in Imperial Rome. This will be accomplished through a digital case study on the largest surviving bath complex in Rome, the Baths of Caracalla, for which we have evidence of the types of materials used in its construction and speculative observations on the quarries from which this material was procured. In order to effectively demonstrate this system and to accurately locate the Baths of Caracalla within the imperial trade network, a detailed visualization of the marble quarries and the web of transportation routes using ArcGIS Pro mapping software was created. Using ArcGIS Pro as a heuristic tool, this map will show the quarry sites and reconstruct the transportation routes by which marble was moved over long distances for the Baths of Caracalla in Rome. While the digital humanities have used the city of Rome as a site for experimental mapping projects on various subjects, this map on the stone quarries in the Roman Empire in relation to the Baths of Caracalla will be the first digital humanities mapping project of its type.
Item Open Access Assessing Land Availability for Utility Solar in North Carolina Using GIS(2017-04-28) Brawner, Eric; Wang, Yifu; Hassaram, Janesha; Wiesner, HoelThe use of utility-scale solar photovoltaic (PV) systems to generate electricity has been increasing substantially in the U.S., and North Carolina is a leading state in its installation. Optimally siting utility PV projects can maximize power generation and reduce projects’ costs, environmental impacts, and social opposition. Our analysis develops a GIS method to optimize siting these projects and assess how suitability factors affect land availability over large areas. We first identify criteria important for siting utility PV projects, such as land-cover, slope, and proximity to electrical substations. We then assess how the stepwise addition of these criteria, from most to least stringent, reduces the availability of suitable land across North Carolina. As the use of utility solar grows in North Carolina, our analysis provides a relevant assessment of siting constraints, identifies prime locations, and quantifies the state’s theoretical potential for this power source.Item Open Access Assessing the Potential for Community Solar in Durham, North Carolina(2012-04-27) Iler, StuartSeveral barriers work against the deployment of rooftop solar photovoltaic systems in Durham and across the country. These include high initial investments that can outweigh benefits, operation and maintenance responsibilities, potentially lengthy payback periods, and significant transaction costs. The community solar model – which encompasses a set of innovative ownership, financing, and other mechanisms – is one option for overcoming these obstacles. There are many potential benefits of community solar, with two primary objectives being reduced initial costs and increased access to renewable energy. Other potential benefits include better economies of scale, more flexibility in choosing an optimal solar site, greater public awareness and understanding of solar energy, the potential for local job creation, and the opportunity to test new ownership and financing structures. This project assesses the degree to which community solar might provide benefits in Durham as measured by two key metrics: reduced costs and increased access to renewable energy. A Geospatial Information Systems (GIS) analysis of three Durham study areas was conducted to estimate the size of possible rooftop solar systems and the amount of annual energy they would provide. A simple energy cost ratio – obtained by dividing total installed cost by annual energy output – was calculated for each parcel, and then averages were determined for each of three parcel categories: residential, commercial, and community service. Graphs were also created to illustrate the relationships between suitable solar rooftop areas, differences in energy cost ratios, and parcels of different types. The analysis provides evidence that the community solar approach has the ability to both reduce the costs of and increase access to renewable solar energy. Although some residential parcels have rooftops that could host cost-efficient systems, for many homeowners a financial advantage might be realized through investment in a community solar project. The study also found that approximately 10% of residential parcels are not suitable for solar systems, while an additional 18% are suitable only for systems smaller than 1 kW. For these people, as well as for those who live in apartment buildings, the opportunity to invest in community solar would be a tangible increase in access to the benefits of renewable energy. As such, the paper concludes by recommending that legislation extending the net metering concept to community energy be adopted at the North Carolina state level.Item Open Access Climate and Conservation: Site Prioritization in the North Carolina Coastal Plains(2022-04-22) Gaffney, MichaelLand trusts are typically focused on preserving land for the purposes of recreation, education, and biodiversity. Recently, however, many land trusts have begun to see their rationale extending beyond these traditional goals to include using land for different kinds of social benefits. Working with the North Carolina Coastal Land Trust, my project designed a geospatial method of analysis to optimize site prioritization for traditional conservation values as well as climate adaptation and mitigation. More specifically, I developed a method of ranking and selecting parcels for NCCLT based on their capacity to promote biodiversity, reduce flooding (through the restoration of headwater wetlands), and sequester carbon (through forestation and wetland restoration). I applied this method to two watersheds in eastern North Carolina, the Upper Cashie and the Waccamaw, and provided a ranked list of properties recommended for conservation.Item Open Access Community-Based Stormwater Mitigation: Rescuing a Clam Fishery in Middens Creek, N.C.(2008-04-24) Durkee, Stephen J.Eastern North Carolina’s expansive aquatic environment, with large lagoonal sounds tapering into winding inland waterways, maximizes the number of residents with direct influence on our coastal waters. Such a system creates a complex management scenario where regulating non-point source pollution proves difficult. To examine sources and potential remedies of fecal coliform loading, a study was initiated in our model waterway, Middens Creek, where active shellfish harvesting is ongoing. Through a multi-phase investigation, current legislation aimed at reducing stormwater impacts is reviewed and pre- and post-storm fecal coliform levels characterized. It became evident during the course of the study that non-point source runoff is the primary way fecal coliform is conveyed into Middens Creek. Quantifying the impact of this runoff in the subwatershed was further extended to examine the statistical link between human development and bacteria levels within the creek and significant correlations between the two were found. Finally, public outreach and education was initiated to affect grassroots change among the residents living along the model waterway in an effort to mitigate the trend anthropogenic impacts.Item Open Access Convenience Analysis of the Oregon Paint Management Pilot Program(2011-04-29) Strickland, Cecilia HedrickThe US Environmental Protection Agency estimates that approximately 10%, or 64 million gallons, of the architectural paint that is purchased annually in the United States is left over. This represents a disposal cost to municipalities of about $8 per gallon, or half a billion dollars per year. Oregon’s Paint Product Stewardship Law, passed in the summer of 2009 and implemented in July 2010, is the nation’s first manufacturer-financed program for managing leftover architectural paint. This program is currently undergoing evaluation, the results of which will be used to more effectively implement similar programs nationwide. The objective of my project is to determine how convenient the drop-off locations are for Oregon residents, including those in urban and rural areas, based on the travel time and distance to the nearest drop-off facility. I generated service areas and estimated the percentage of each census block’s population that resides within the service areas as equal to the percentage of total road length in each block that is included in the service area. Based on this analysis, more than 90% of Oregon residents live within 20 minutes, or 15 miles, of the nearest collection facility. This degree of convenience, however, is not evenly distributed throughout the state. The most underserved residents include those living in Gilliam, Douglas, Polk, and Lincoln counties. Fewer than 3% of Gilliam county residents live within 15 miles of a drop-off location, compared to 40% in the county with the next lowest percentage. Likewise, Douglas, Polk, and Lincoln counties have a low percentage of residents within 15 miles of a drop-off location and they have among the largest number of people, relative to other counties, outside of this service area. Additionally, I developed a Site Selection and Convenience Analysis tool to aid in the selection of drop-off facilities based on the same convenience criteria. This tool is flexible and adaptive. It can be used during the development of recycling programs in other areas to determine which set of potential drop-off sites provide the best access to residents or which potential drop-off sites best complement the existing network of drop-off sites.Item Open Access Ecological and Financial Suitability of Sites for Long-Term Oak Management in Western North Carolina(2021-04-30) Scott, MichaelFor thousands of years, oak species have been the dominant canopy species in eastern and central United States hardwood forests. Oaks (Quercus spp.) provide myriad ecological services and arguably comprise the most valuable hardwood timber genus in the eastern US. In recent decades, however, research shows that oaks are declining in density and being outcompeted by fast growing species like yellow poplar (Liriodendron tulipifera) and red maple (Acer rubrum). Due to oak fire tolerance, and ability to withstand droughts and poor soil conditions, Quercus promises to be a vital genus for climate resiliency. Western North Carolina has historically supported expansive oak dominated forests, and organizations are now concerned about protecting this valuable ecosystem. This project sought to identify land in western North Carolina that is ecologically and financially suitable for oak management and to understand the following questions: 1) Where is oak management ecologically viable? 2) What is the financial potential for oak management? 3) Where can loggers access timber? This was accomplished by conducting a survey and literature review about logger accessibility in the mountains, creating an oak management prioritization map and GIS tool using logger data and oak ecological requirements, and a financial analysis of the profitability of oak silviculture prescriptions. The results will help The Nature Conservancy (TNC) identify high priority areas to initiate oak management systems. With careful planning, oak management can be financially viable in western North Carolina.Item Open Access Effects of Wildfire on Vegetation Composition and Structure in Linville Gorge Wilderness Area, North Carolina(2015-04-24) Pallai, CassandraLocated in Western North Carolina, Linville Gorge Wilderness Area has an extensive fire history that has been characterized by burns of variable size and severity. Beginning in the 1940s, an era of burn suppression policies curtailed the Gorge’s established fire regime. Local stakeholders, including The Wilderness Society (TWS) and the U.S. Forest Service, are concerned about the effects of burn suppression on fire dependent species and communities. As such, these groups are interested in following a modern resurgence of anthropogenic wildfires with a prescribed fire program. Many sampling efforts since 1992 have studied permanent vegetation plots spread throughout Linville Gorge to characterize local plant communities and their relationship with five recent fires. With my Master’s Project, done for The Wilderness Society, two objectives related to fire in the Gorge are addressed. First, structural and compositional trends in Linville Gorge forests have been identified, and those trends have been overlain with geospatial environmental variables as well as remotely sensed fire severity estimations. Second, wildfires have been evaluated for their meeting of restoration goals. TWS’s restoration targets include a reduction in the importance of ericaceous and fire intolerant species, an increase in the importance of fire dependent species, and a lack of invasion from nonnative species following fire events. Multivariate statistical methods have been implemented to analyze the Linville vegetation dataset for structural and compositional trends, and paired t-tests have been utilized to evaluate changes in target species’ importance with fire. Fire has emerged as a major driver of change and compositional heterogeneity in the Wilderness Area. However, burns have produced variable success in meeting restoration goals. While ericaceous species have been reduced in importance, fire dependent species also have experienced declines. Fire intolerant species have increased in abundance with fire; similar increases have not been observed on unburned plots. Invasive species may be a concern, particularly in twice burned forests. If prescribed fire is pursued as a restoration tool in Linville Gorge Wilderness Area, managers should be careful in planning the frequency and severity of fires, and continue to monitor results for the achievement of goals.Item Open Access Ellerbe Creek Green Infrastructure Implementation Plan(2016-04-22) Close, Amanda; Davis, Christina; Williams, BethanyEllerbe Creek is a severely degraded urban stream located in Durham, NC. The high percentage of impervious surface within its watershed has contributed to altered hydrology and increased inputs of nitrogen, phosphorus, and other forms of aquatic pollution. This project expands on previous work by the Ellerbe Creek Watershed Association (ECWA) to investigate opportunities for controlling the volume and pollutant load of stormwater runoff using dispersed green infrastructure technologies. A 3-pronged methodology that utilized geospatial analysis, field data collection, and scenario planning using cost-effectiveness optimization was employed to identify and prioritize potential green infrastructure retrofits within a sub-catchment of the watershed. Results of the project equip ECWA with both the data necessary to begin implementing the identified residential retrofits and a tool kit that can be used to expand the analysis to the entire Ellerbe Creek Watershed.Item Open Access Evaluating the Visualization of Fisheries Data in the Northeastern United States(2017-04-21) Pearce, JustinIn October 2016, the Northeast Regional Planning Body (NEPRB) released the nation’s first regional ocean plan. The NEPRB identified the Northeast Ocean Data Portal as a resource that supports their goal of moving towards ecosystem-based regulatory decisions. In an effort improve the fish data on the portal this study compares fish biomass data collected between 2007-2014 from two scientific trawls. The Northeast Fisheries Science Center conducts trawls in federal waters off of the Northeastern United States, and the Northeast Area Monitoring and Assessment Program uses similar trawl methodology in the adjacent state waters. Seven species were selected due to their similar distribution and abundance in each dataset. Then, the species were compared using geospatial and statistical analysis. Although results varied between species, there is no indication of high correlation between datasets. These results shine a light on potential ways to improve trawl methodologies to make the surveys more comparable. Also, understanding the differences between these datasets should urge the NEPRB to reconsider single-species data maps for more user-friendly, habitat-based, maps on the portal.Item Open Access Facilitating Coastal Stormwater Management in North Carolina: Runoff Estimation and Institutional Education(2014-04-18) Zaykoski, PeterIn coastal North Carolina, increased surface runoff from urban, agricultural, and forestry development contaminates coastal waters and has led to extensive shellfishing area closures. Coastal communities looking to restore their waters become eligible for restoration funding when they complete watershed restoration plans with numeric pollutant reduction goals. In this work, I present a new geospatial analysis tool for calculating modern and historic stormwater runoff estimates, which can be used as proxies for restoration goals. This tool uses satellite-derived land cover, soils, and precipitation data to provide stormwater estimates using a watershed boundary as the minimum required input. Additionally, to improve the accuracy of estimates, the tool has optional inputs for the proportion of impervious surface that is disconnected in the watershed and for areas drained for forestry operations. I compare the results from this estimator with the more labor intensive methods used in previous stormwater management plans and with estimates from SWARM (Stormwater Runoff Modelling System), recently developed by NOAA. Finally, I provide recommendations for how to best integrate these tools into the current management framework.Item Open Access Febrile Disease Epidemiology and Geospatial Modeling in Southern Sri Lanka(2011) Gong, WenfengAs a subproject under the collaboration between Ruhuna University in Sri Lanka and Duke University, this study focused on the identification of socioeconomic and ecological determinants of febrile illness in Galle district. We integrated socioeconomic data from local government, ecological data from national geographic information system (GIS) database, and febrile patients' epidemiologic data from clinical investigation. The integrated database was prepared using GIS techniques and validated via field visits. Missing population data were simulated through Bayesian imputation. While the febrile disease risk is not measurable in the current study, social and ecological predictors of disease distribution (proportion of specific disease in all cases) were identified for the enrolled Teaching Hospital Karapitiya (THK) patients. These predictors are potentially the determinants of febrile disease in Galle. Due to the limitation of single-center clinical sampling, patient travel distance was highly associated with patient visits, thus, it became a strong confounder in analyses. After adjusted for the confounders, a set of patients' social/ecological exposures were found to be associated with dengue, leptospirosis, URTI, LRTI, gastroenteric infection, and/or undifferentiated febrile illness.
Item Open Access Geographic Expansion of Lyme Disease in the Southeastern United States, 2000-2014.(Open Forum Infect Dis, 2015-12) Lantos, Paul M; Nigrovic, Lise E; Auwaerter, Paul G; Fowler, Vance G; Ruffin, Felicia; Brinkerhoff, R Jory; Reber, Jodi; Williams, Carl; Broyhill, James; Pan, William K; Gaines, David NBackground. The majority of Lyme disease cases in the United States are acquired on the east coast between northern Virginia and New England. In recent years the geographic extent of Lyme disease has been expanding, raising the prospect of Lyme disease becoming endemic in the southeast. Methods. We collected confirmed and probable cases of Lyme disease from 2000 through 2014 from the Virginia Department of Health and North Carolina Department of Public Health and entered them in a geographic information system. We performed spatial and spatiotemporal cluster analyses to characterize Lyme disease expansion. Results. There was a marked increase in Lyme disease cases in Virginia, particularly from 2007 onwards. Northern Virginia experienced intensification and geographic expansion of Lyme disease cases. The most notable area of expansion was to the southwest along the Appalachian Mountains with development of a new disease cluster in the southern Virginia mountain region. Conclusions. The geographic distribution of Lyme disease cases significantly expanded in Virginia between 2000 and 2014, particularly southward in the Virginia mountain ranges. If these trends continue, North Carolina can expect autochthonous Lyme disease transmission in its mountain region in the coming years.