<p> Eastern Equine Encephalitis virus is a vector-borne virus amplified by the <i>Culiseta melanura</i> mosquito in an enzootic avian cycle, causing high morbidity and mortality to horses and humans when contracted as incidental hosts. The virus is distributed across most of the eastern United States, Canada, and Gulf coast, and has been expanding in geographic range and season of activity over time. Spatial-temporal trends in <i>Cs. melanura </i> abundance were correlated with available meteorological (temperature and precipitation) and remotely sensed environmental data for the period of 1997-2012 in Connecticut. The effects of inter-annual changes in precipitation, temperature, and groundwater levels on <i>Cs. melanura</i> abundances using time-series linear regression and cross-correlation analyses were inconclusive. Habitat modeling using logistic regression and landscape-based predictive variables demonstrated strong efficiency (46.2%) and acceptable sensitivity and specificity (65.6 and 78.6%, respectively) using NDVI difference and distance from palustrine areas as predictive factors. Remotely sensed data can improve the understanding of vector abundance patterns, helping to forecast future outbreaks and regional expansions by guiding surveillance efforts. </p>

published_or_final_version / Geography and Geology / Doctoral / Doctor of Philosophy

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Geography / Master / Master of Geographic Information System

No description available.

Protecting and managing National Parks and Monuments effectively is very important for their future sustainability. Urban encroachment on areas adjacent to protected areas is often considered a potential threat to the natural resources inside the protected areas. To minimize these threats, evaluating and assessing the effects of urban encroachment on protected areas and developing effective management strategies is critical. To implement any management strategy, interactions, support and perceptions of changing conditions from neighboring communities is imperative. The goal of this study was to develop a framework to assess perception of land use change along the borders surrounding Saguaro National Park East. The objectives of this study were to determine 1) the change in landscape that has occurred as a result of urban encroachment in and adjacent areas to Saguaro National Park (SNP) over a 15 year period 2) the degree to which neighbors surrounding SNP perceive that these changes have occurred due to urban encroachment 3) the perception of neighbors surrounding SNP that increased urbanization has led to more impacts on local wildlife 4) the possible planning and management strategies that neighbors agree would lead to reduce impacts of urban encroachment on protected areas and how strongly do they support the implementation of these proposed planning and management strategies. Results of this study indicated that landuse / landcover changes have occurred over the landscape at a rapid rate and in large areas within one mile of lands adjacent to the boundary of SNP East. Urban area increased 2.45%, agricultural lands decreased 76.15% and forested lands decreased 6.19% from its previous class in one mile adjacent land to the park from 1992 - 2001. Building units (residential) increased dramatically by 71.53% in this one mile buffer in the period between 1992 and 2007. In addition, respondents that live in adjacent lands perceive these changes over the landscape due to urban encroachment at a moderate degree strongly agree that increased urbanization has led to more negative impacts on local wildlife. Further, respondents strongly support more communication between authorities, developers and neighbors and environmental education programs with regards to urban encroachment on SNP.

No description available.

<p> The work described is aimed at developing a unique and modifiable model for analyzing transit system improvements, with specific emphasis on the concept of Transit-Oriented Development (TOD). In particular, the use of multiple variables that have been developed over the years as a result of a number of transit analyses, in a novel manner is described. The area of study was the light rail transit system (LRT) known as Lynx in Mecklenburg County, NC and over a period of development between 2001 and 2012 which included the actual construction phase from 2005 to 2007. An index model was developed to combine and magnify the potential impacts of each of the identified variables as they related to one another and the surrounding urban environment. These variables included land value, housing unit density, and others that are often been associated with TOD. The results of this combined and comprehensive analysis served to identify areas that are likely associated with the transit system, primarily proximity to the LRT system, i.e., areas where changes in the TOD-related variables were consistent with a positive relation to recognized TOD principles. Some areas within the service area showed especially high positive attributes of TOD, for example, Uptown Charlotte, a major hub of a current phase of LRT development, as well areas of other future enhancements. An extension of the work described should include the evaluation of additional variables as applicable data sets are made available, including, but not limited to, employment change, property vacancy statistics, and crime.</p>

<p> Riparian vegetation restoration efforts demand cost effective, accurate, and replicable impact assessments. In this thesis a method is presented using an Unmanned Aerial Vehicle (UAV) equipped with a GoPro digital camera to collect photogrammetric data of a 2.02-acre riparian restoration. A three-dimensional point cloud was created from the photos using Structure from Motion (SfM) techniques. The point cloud was analyzed and compared to traditional, ground-based monitoring techniques. Ground truth data collected using the status-quo approach was collected on 6.3% of the study site and averaged across the entire site to report stem heights in stems/acre in three height classes, 0-3 feet, 3-7 feet, and greater than 7 feet. The project site was divided into four analysis sections, one for derivation of parameters used in the UAV data analysis, and the remaining three sections reserved for method validation. The most conservative of several methods tested comparing the ground truth data to the UAV generated data produced an overall error of 21.6% and indicated an r² value of 0.98. A Bland Altman analysis indicated a 99% probability that the UAV stems/plot result will be within 159 stems/plot of the ground truth data. The ground truth data is reported with an 80% confidence interval of +/- 844 stems/plot, thus the UAV was able to estimate stems well within this confidence interval. Further research is required to validate this method longitudinally at this same site and across varying ecologies. These results suggest that UAV derived environmental impact assessments at riparian restoration sites may offer competitive performance and value.</p>

<p> Over the past 30 years, wildland fire and native bark beetle outbreaks have increased in intensity, severity, and extent across the fire-prone forests of the western United States, raising concerns about whether bark beetle outbreaks increase wildfire severity and/or wildfire occurrence. Furthermore, current estimates predict a two-fold increase in area burned by wildland fires over the next 25 years and bark beetles are forecasted to expand in the coming century, shifting toward higher latitudes and elevations. Thus, it is important to better understand how insect-driven tree mortality may affect fire risk and how these disturbance interactions may affect ecosystem structure and dynamics across biophysical settings under current and future climate scenarios. </p><p> In this dissertation, I investigated the relationships between bark beetle outbreaks, wildfire, and climate across the western United States and within subalpine forests of the Southern Rocky Mountains, CO, USA. The main research questions of this dissertation were: (Chapter II) what is the relative importance of mountain pine beetle (<i>Dendroctonus ponderosae</i> (Hopkins)) outbreaks versus antecedent climatic variability on the occurrence of large wildfires in the western U.S.? (Chapter III) how do pre-outbreak forest conditions mediate the effects of spruce beetle (<i>Dendroctonus rufipennis</i> (Kirby)) outbreaks on fuels complexes in subalpine forests of Colorado? and (Chapter IV) how do changes in fuels following spruce beetle outbreaks affect expected fire potential under current and future climate conditions? </p><p> Chapter II employed a variety of remotely sensed data and GIS products of fire occurrence, mountain pine beetle outbreaks, physiographic gradients, and climatic condition to test whether prior-disturbance or antecedent climate conditions influenced subsequent wildfire events. Extensive field surveys of stand attributes and fuel arrangements across a chronosequence of spruce beetle outbreaks in the 20th and 21st century were employed to address research questions of Chapter III. Results from Chapter III were used as base inputs for custom fire behavior models in Chapter IV, to test the sensitivity of potential fire behavior across a variety of wind speeds, weather, and climate scenarios. </p><p> Despite widespread concern that mountain pine beetle outbreaks lead to unprecedented increases in wildfire activity, results from Chapter II demonstrated minimal effects of these pre-fire disturbances on subsequent fire occurrence. Instead, occurrence of large wildfires across the western US has been driven by extreme weather (e.g., hot, dry conditions). Chapter III revealed that the changes to fuels following spruce beetle outbreaks are strongly contingent on pre-outbreak stand structure and disturbance history. For instance, we found that spruce beetle outbreaks reduce canopy fuels in all stands, yet this effect is relatively minor in old spruce-fir stands as compared to young spruce-fir stands. Spruce beetle outbreaks during the 20^th and 21^st century decreased canopy fuels and increased their heterogeneity, regardless of pre-outbreak conditions. Surface fuel loads were more variable with increased time since spruce beetle outbreak and did not return to pre-outbreak conditions over the 75-year period considered in this study in both young and old stands. Chapter IV concluded that under all weather and climate scenarios, stands affected by spruce beetle had the lowest potential for increased surface fireline intensities, rates of spread, and active crowning among both young and old stands as compared to endemic stands (i.e., non-outbreak). Chapter IV used future climate projections (2016-2100) of RCP 4.5 and RCP 8.5 as proxies for moderate and severe climate change and concluded that moderate climate change will not substantially increase the most important types of fire behavior among young or old stands, nor stands affected by spruce beetle outbreak as compared to current climate (1985-2015). However, under severe climate change projections (RCP 8.5) all characteristics of fire behavior will increase, regardless of stand age, spruce beetle outbreak, and wind and weather scenarios. This research provides much needed insight into the disturbance dynamics in fire-prone forests and informs forest management and policy concerns under a changing climate. Overall, this research highlights the 1) dominant effect of climate, rather than outbreaks, has on fire regimes across the western United States and 2) the importance of accounting for pre-disturbance stand structure and disturbance histories on subsequent disturbance patterns and severities.</p>