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<p> Electoral districts drawn by independent commissions are seen by political reformers to be preferable to those drawn by state legislatures. The overtly partisan interests of elected officials, say the reformers, lead to oddly-shaped, and gerrymandered districts. To test this, shapes of districts in states with commissions are compared to those within the same state prior to the commission&rsquo;s establishment. Additionally, shapes of districts in states with commissions are compared to those in a selected group of states without commissions. This study tests hypotheses on two methods of measuring compactness, Reock and Polsby-Popper, and coterminosity, the congruence of district lines and pre-existing political boundaries. The study finds that each state with a commission shows no significant difference in mean compactness compared to its pre-commission form. However, in aggregate, all post-commission districts show a significant increase in mean Reock compactness compared to all pre-commission districts, and all districts in states with commissions show significantly less Polsby-Popper compactness than districts in non-commission states. The study also finds no significant difference in coterminosity between commission states and non-commission states. Though the true effect of commissions may not be discernible from averages, other redistricting criteria also need to be controlled for and evaluated over time.</p>

<p> Water resources have become an increasingly important topic in the world of resource management. Researchers are constantly looking for ways to make the process of data collection, analyzation and visualization more efficient. The current methods involve a multi-step process that is cumbersome and require a lot of man-hours from start to finish. The cost of water quality sensors is also an issue for researchers. Many sensors on the market today range from the $1,000 to $10,000 range making it difficult for small research firms and non profits to conduct water quality monitoring projects. This project attempts to construct a water quality-monitoring platform that will automate the process of collecting, analyzing and visualization water quality data. Special attention will be given to the data visualization aspect of the process with an emphasis on web mapping applications.</p>

<p> The Truckee Meadows (Reno, NV) sits in a tectonically complex area of western Nevada, where Walker Lane-style transtension is dominant throughout the region. A new Light Detection and Ranging (LiDAR) study focuses on the Truckee Meadows region of western Nevada, including the Reno/Sparks metropolitan area in Washoe County. We use the airborne LiDAR imagery (1485 sq. km) to create high quality, bare-earth topographic maps that were previously unattainable in vegetated, populated or alpine terrain. This approach gives us an opportunity to improve fault maps that may be outdated or incomplete in the area. Here we provide LiDAR imagery of a large section of Washoe County and an updated fault map of the greater Truckee Meadows region. </p><p> We also use this new LiDAR survey of the Truckee Meadows and nearby basins to constrain geometry, length, distribution, and slip rates along faults imaged by this new dataset. Estimated slip rates are compared to those derived from a geodetic block model constrained by Global Positioning Station (GPS) data to test for consistency. GPS station data and geologic mapping show that both east-west oriented extension and northwest-oriented right-lateral strike slip accommodate transtension as a backdrop for tectonics studies of region, with some northeast-oriented left-lateral strike slip. This study aims to better understand how this transtension is partitioned along remapped faults and newly identified structures in this urban setting, as the framework for strain accommodation in this area remains poorly understood. </p><p> Faults with normal offset were measured along strike using bare-earth LiDAR returns to determine the amount of vertical separation across geomorphic surfaces, and then converted to extension assuming a fault dip of 60 (+/-10) degrees. Since the primary geomorphic surfaces in this region are the result of Sierra Nevadan glacial outwash episodes, we use previously published geologic maps to link each surface to an associated date. When integrated across several basin perpendicular transects within the Mt. Rose pediment, we calculate a total extension rate of 0.87 (+0.40/-0.48) mm/yr for the southern Truckee Meadows basin. Integrated slip rates from fault scarp offsets are within the bounds of 1.23 (+/-0.70) mm/yr suggested by geodetic modeling. Block modeling highlights that north-striking faults primarily accommodate east-west extension, and so northwest-striking faults and/or block rotations must accommodate the northwest-directed shear seen in GPS velocities. This trend is bolstered by the discovery of a new northwest-oriented fault on Peavine Mountain 6 km east of the Mogul (2008) seismicity trend. Our study provides further evidence that the Truckee Meadows sits at a critical transition from north-striking normal faults in the southern part of the basin to northwest-oriented strike-slip faults to the north, an observation that mimics regional tectonics and geomorphology of the adjacent Lake Tahoe/Truckee system to the west.</p>

<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>

<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>

<p> In this thesis, path planning for an autonomous ground vehicle (AGV) in an urban environment is considered. The following problem is considered. starting from an initial location, the AGV desires to reach a final location by taking the shortest distance, while minimizing the AGVs position estimation error and guaranteeing that the AGVs position estimation uncertainty is below a desired threshold. The AGV is assumed to be equipped with receivers capable of producing pseudodange measurements on Global Navigation Satellite System (GNSS) satellites and cellular long-term evolution (LTE) towers. Using a geographic information system (GIS) three-dimensional (3-D) building map of the urban environment, a signal reliability map is introduced, which provides information about regions where large errors due to cellular signal multipath or poor GNSS line-of-sight (LOS) are expected. The vehicle uses the signal reliability map to calculate the position estimation mean-squared error (MSE). An analytical expression for the AGV's state estimates is derived for a weighted nonlinear least-squares (WNLS) estimator, which is used to find an analytical upper bound on the position bias due to multipath. A path planning approach based on Dijkstra's algorithm is proposed to optimize the AGV's path while minimizing the path length and the position estimation MSE, subject to keeping the position estimation uncertainty and position estimation bias due to multipath being below desired thresholds. The path planning approach yields the optimal path together with a list of feasible paths. Simulation results are presented demonstrating that utilizing ambient cellular LTE signals together with GNSS signals (1) reduces the uncertainty about the AGV's position, (2) increases the number of feasible paths to choose from, which could be useful if other considerations arise, e.g., traffic jams and road blockages due to construction, and (3) yields significantly shorter feasible paths, which would otherwise be infeasible with GNSS signals alone. Experimental results on a ground vehicle navigating in downtown Riverside, California, are presented demonstrating a close match between the simulated and experimental results.</p><p>