Matching Items (4)
Description
Recent advances in geo-visualization technologies, such as Google Earth, have the potential to enhance spatial thinking. Google Earth is especially suited to teaching landforms and geomorphological processes in traditional, online, or hybrid college classroom settings. The excitement for the technology as a learning tool, however, must be tempered by the need to develop sound and supportive pedagogies. A fundamental gap in the geoscience education literature exists because learning experiences with Google Earth, from the perspective of the student, are not completely understood. This dissertation analyzes three case studies in college introductory physical geography (Chapters 2 and 4) and teacher education (Chapter 3) courses at Arizona State University where students completed an online (Chapter 2 and 3) laboratory that used Google Earth as the main tool for landform identification and interpretation, and a hardcopy laboratory and in-field exercise (Chapter 4) that compared Google Earth oblique with traditional stereopair air photo and planimetric perspectives. Gauging student performance in these tasks, along with their formative and summative opinions for `what it was like to learn this way', provide information as part of a feedback loop to develop and improve instructional scaffolding and best practices so that the focus remains on the content-to-be-learned and not the tool. These case studies show that, in general, prior use of Google Earth is usually not a limiting factor; multiple perspectives and supplemental visualizations of landforms with Google Earth's may enhance the learning experience; the hands-on nature of structured Google Earth exploration in these labs are virtual field trips that increase enjoyment and fit within a learner-centered curriculum; scaffolding landform-learning exercises for aspiring elementary school teachers linked to children's literature assists the development of content knowledge for teaching physical geography and spatial thinking; and, finally, despite a virtual globe's high-quality visualizations and promising potential for learning, there is still a role for stereopair images in the geomorphology classroom.
ContributorsPalmer, Ronald Evan (Author) / Dorn, Ronald I. (Thesis advisor) / Harris, Lauren M (Committee member) / Cerveny, Niccole V (Committee member) / Arizona State University (Publisher)
Created2014
Description
Urbanization, a direct consequence of land use and land cover change, is responsible for significant modification of local to regional scale climates. It is projected that the greatest urban growth of this century will occur in urban areas in the developing world. In addition, there is a significant research gap in emerging nations concerning this topic. Thus, this research focuses on the assessment of climate impacts related to urbanization on the largest metropolitan area in Latin America: Mexico City.
Numerical simulations using a state-of-the-science regional climate model are utilized to address a trio of scientifically relevant questions with wide global applicability. The importance of an accurate representation of land use and land cover is first demonstrated through comparison of numerical simulations against observations. Second, the simulated effect of anthropogenic heating is quantified. Lastly, numerical simulations are performed using pre-historic scenarios of land use and land cover to examine and quantify the impact of Mexico City's urban expansion and changes in surface water features on its regional climate.
Numerical simulations using a state-of-the-science regional climate model are utilized to address a trio of scientifically relevant questions with wide global applicability. The importance of an accurate representation of land use and land cover is first demonstrated through comparison of numerical simulations against observations. Second, the simulated effect of anthropogenic heating is quantified. Lastly, numerical simulations are performed using pre-historic scenarios of land use and land cover to examine and quantify the impact of Mexico City's urban expansion and changes in surface water features on its regional climate.
ContributorsBenson-Lira, Valeria (Author) / Georgescu, Matei (Thesis advisor) / Brazel, Anthony (Committee member) / Vivoni, Enrique (Committee member) / Arizona State University (Publisher)
Created2015
Description
ABSTRACT
Famine is the result of a complex set of environmental and social factors. Climate conditions are established as environmental factors contributing to famine occurrence, often through teleconnective patterns. This dissertation is designed to investigate the combined influence on world famine patterns of teleconnections, specifically the North Atlantic Oscillation (NAO), Southern Oscillation (SO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), or regional climate variations such as the South Asian Summer Monsoon (SASM). The investigation is three regional case studies of famine patterns specifically, Egypt, the British Isles, and India.
The first study (published in Holocene) employs the results of a Principal Component Analysis (PCA) yielding a SO-NAO eigenvector to predict major Egyptian famines between AD 1049-1921. The SO-NAO eigenvector (1) successfully discriminates between the 5-10 years preceding a famine and the other years, (2) predicts eight of ten major famines, and (3) correctly identifies fifty out of eighty events (63%) of food availability decline leading up to major famines.
The second study investigates the impact of the NAO, PDO, SO, and AMO on 63 British Isle famines between AD 1049 and 1914 attributed to climate causes in historical texts. Stepwise Regression Analysis demonstrates that the 5-year lagged NAO is the primary teleconnective influence on famine patterns; it successfully discriminates 73.8% of weather-related famines in the British Isles from 1049 to 1914.
The final study identifies the aggregated influence of the NAO, SO, PDO, and SASM on 70 Indian famines from AD 1049 to 1955. PCA results in a NAO-SOI vector and SASM vector that predicts famine conditions with a positive NAO and negative SO, distinct from the secondary SASM influence. The NAO-famine relationship is consistently the strongest; 181 of 220 (82%) of all famines occurred during positive NAO years.
Ultimately, the causes of famine are complex and involve many factors including societal and climatic. This dissertation demonstrates that climate teleconnections impact famine patterns and often the aggregates of multiple climate variables hold the most significant climatic impact. These results will increase the understanding of famine patterns and will help to better allocate resources to alleviate future famines.
Famine is the result of a complex set of environmental and social factors. Climate conditions are established as environmental factors contributing to famine occurrence, often through teleconnective patterns. This dissertation is designed to investigate the combined influence on world famine patterns of teleconnections, specifically the North Atlantic Oscillation (NAO), Southern Oscillation (SO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), or regional climate variations such as the South Asian Summer Monsoon (SASM). The investigation is three regional case studies of famine patterns specifically, Egypt, the British Isles, and India.
The first study (published in Holocene) employs the results of a Principal Component Analysis (PCA) yielding a SO-NAO eigenvector to predict major Egyptian famines between AD 1049-1921. The SO-NAO eigenvector (1) successfully discriminates between the 5-10 years preceding a famine and the other years, (2) predicts eight of ten major famines, and (3) correctly identifies fifty out of eighty events (63%) of food availability decline leading up to major famines.
The second study investigates the impact of the NAO, PDO, SO, and AMO on 63 British Isle famines between AD 1049 and 1914 attributed to climate causes in historical texts. Stepwise Regression Analysis demonstrates that the 5-year lagged NAO is the primary teleconnective influence on famine patterns; it successfully discriminates 73.8% of weather-related famines in the British Isles from 1049 to 1914.
The final study identifies the aggregated influence of the NAO, SO, PDO, and SASM on 70 Indian famines from AD 1049 to 1955. PCA results in a NAO-SOI vector and SASM vector that predicts famine conditions with a positive NAO and negative SO, distinct from the secondary SASM influence. The NAO-famine relationship is consistently the strongest; 181 of 220 (82%) of all famines occurred during positive NAO years.
Ultimately, the causes of famine are complex and involve many factors including societal and climatic. This dissertation demonstrates that climate teleconnections impact famine patterns and often the aggregates of multiple climate variables hold the most significant climatic impact. These results will increase the understanding of famine patterns and will help to better allocate resources to alleviate future famines.
ContributorsSantoro, Michael Melton (Author) / Cerveny, Randall S. (Thesis advisor) / McHugh, Kevin (Committee member) / Brazel, Anthony (Committee member) / Balling Jr., Robert C. (Committee member) / Arizona State University (Publisher)
Created2017
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