Matching Items (2)
Description
Anthropogenic activities have had a profound effect on ecosystems, sediment budgets, and dust emissions stemming from widespread changes in land use and land cover and increases in sediment disturbance. Sandy coastal environments are under increasing pressure from the impacts of rising sea levels, coastal flooding, and erosion. Coastal foredunes can serve as a buffer to protect coastal communities from the impacts of coastal erosion, flooding, and sea-level rise. They also serve an important role as an ecosystem service, providing opportunities for recreation (off-highway vehicle, hiking, tourism) and habitat for native and endemic biota. Increased disturbance and pressure by human activity within the beach-dune system can lead to a decoupling of form and function from natural geomorphic and biotic processes. Dune management and restoration is often employed to mitigate some of the aforementioned pressures. Dynamic or ‘nature-based’ restoration aims to restore the form and function of a geomorphic system and improve landform resilience to external pressures by employing complimentary native plant species. This type of approach places emphasis on the ecological and geomorphic interactions within a landscape to improve the overall function and resiliency of the system to external pressures. Two case studies along the coast of California, the Lanphere Dunes and Oceano Dunes, provide uniquely different approaches to foredune restoration and the corresponding issues of landscape management for various goals. The case studies provided employ a suite of close-range remote sensing techniques, including kite aerial photography, uncrewed aerial systems photography, and terrestrial laser scanning, to generate high resolution (< 0.1 m) products (surface models; orthophoto mosaics in red-green-blue (RGB) and multispectral) to quantify and inform on restoration efforts by examining sediment budget and vegetation characteristics over a mesoscale (spatial and temporal). Results were compared to a variety of control sites (e.g., no restoration, natively vegetated, invasively vegetated) to highlight the differences between restored and unrestored landscapes, and the efficacy of restoration efforts for improving the developmental trajectory of a landscape towards a "desired" state.
ContributorsHilgendorf, Zach (Author) / Walker, Ian J (Thesis advisor) / Dorn, Ronald I (Committee member) / Schmeeckle, Mark W (Committee member) / Arizona State University (Publisher)
Created2022
Description
The southwestern United States is an ecologically, climatologically, and topographically diverse geographical region. As a result, it has been difficult to develop accurate assessments and instructional pedagogy for defining and demonstrating climate sensitivity and change at a more local level. To address this problem, this dissertation is divided into two distinct sections involving climate data collection/analysis and geography education using interactive geovisualization video games (iGEOs). The first two papers analyze new climate observations in Joshua Tree National Park. The first paper examines the variability in accuracy of climate reanalysis and interpolation methods compared to field observations in Joshua Tree National Park and the Tucson Metropolitan Area. This study found that other than PRISM interpolation data, reanalysis techniques performed better in a region with a more extensive climate network. The second paper developed a climate regionalization zone separating the Mojave and Sonoran Deserts within Joshua Tree National Park using principal component analysis. This study used monthly temperature and precipitation observations, as well as seasonal climate trends. The final two papers describe and analyze the implementation of virtual interactive geovisualization video games (iGEOs) used to instruct geographical concepts in an introductory physical geography course at Arizona State University. The first paper examines the preliminary implementation of an iGEO in the San Francisco Peaks of northern Arizona, identifying student support for the games, but with caveats related to the technical shortcomings of the game design, and noticeable differences based on academic major. The second paper examines the changing experiences and challenges encountered by both students and instructors in an iGEO centered introductory geography course during the COVID-19 pandemic. This study found that, while students were impacted by the pandemic, all student groups had sufficient extensive and intensive learning materials to ensure a positive and successful lab experience. Overall, the significance of these four papers demonstrates that new applications of climate observations and geography pedagogy can effectively describe local climate sensitivity and instruct geographic concepts in the mountainous Southwest.
ContributorsHeintzman, Ryan Joseph (Author) / Cerveny, Randall S (Thesis advisor) / Dorn, Ronald I (Thesis advisor) / Balling Jr, Robert C (Committee member) / Selover, Nancy (Committee member) / Arizona State University (Publisher)
Created2021