Matching Items (144)
Description
Growth of the Phoenix metropolitan area led to exposures of the internal bedrock structure of surrounding semi-arid mountain ranges as housing platforms or road cuts. Such exposures in the Sonoran and Mojave deserts reveal the presence of sedimentary calcium carbonate infilling the pre-existing fracture matrix of the bedrock. Field surveys of bedrock fractures filled with carbonate (BFFC) reveal an average of 0.079 +/- 0.024 mT C/m2 stored in the upper 2 m of analyzed bedrock exposures. Back-scattered electron microscopy images indicate the presence of carbonate at the micron scale, not included in this estimation. Analysis of the spatial extent of bedrock landforms in arid and semi-arid regions worldwide suggests that ~1485 GtC could potentially be stored in the upper 2 m horizon of BFFCs. Radiocarbon dating obtained at one of the sites indicates it is likely that some of the carbonate was flushed into the bedrock system during glacial wet pulses, and is stored on Pleistocene timescales or longer. Strontium isotope analysis at the same site suggest the potential for a substantial cation contribution from weathering of the local bedrock, indicating the potential exists for sequestration of atmospheric carbon in BFFCs. Rates of carbon release from BFFCs are tied to rates of erosion of bedrock ranges in desert climates.
ContributorsHarrison, Emma (Author) / Dorn, Ronald (Thesis advisor) / Reynolds, Stephen (Committee member) / Schmeeckle, Mark (Committee member) / Arizona State University (Publisher)
Created2013
Description
A fundamental gap in geomorphic scholarship regards fluvial terraces in small desert drainages and those terraces associated with integrating drainages. This dissertation analyzes four field-based case studies within the Sonoran Desert, south-central Arizona, with the overriding purpose of developing a theory to explain the formative processes and spatial distribution of fluvial terraces in the region. Strath terraces are a common form (Chapters 2, 3, 4) and are created at the expense of bounding pediments that occur on the margins of constraining mountainous drainage boundaries (Chapters 1, 2, 3). Base-level fluctuations of the major drainages cause the formation of new straths at lower elevations. Dramatic pediment adjustment and subsequent regrading follows (Chapter 3), where pediments regrade to strath floodplains. This linkage between pediments and their distal straths is termed the pediment-strath relationship. Stability of the base level of the major drainage leads to lateral migration and straths are carved at the expense of bounding pediments through an erosional asymmetry facilitated by differential rock decay between the channel bank and bed. Fill terraces occur within the Salt River drainage basin as a result of the integration processes that connect formerly endorheic basins (Chapter 4). The topographic, spatial, and sedimentologic relationship of the Stewart Mountain terrace (Chapter 4) points to a different genetic origin than the lower terraces in this basin. The high Stewart Mountain fill terrace records the initial integration of this river. The strath terraces inset below the Stewart Mountain terrace are a result of the pediment-strath relationship. These case studies also reveal that the under-addressed drainage processes of piracy and overflow have significant impacts in the evolution of drainages the lead to both strath and fill terrace formation in this region.
ContributorsLarson, Phillip Herman (Author) / Dorn, Ron I (Thesis advisor) / Schmeeckle, Mark (Thesis advisor) / Douglass, John (Committee member) / Cerveny, Randy (Committee member) / Arizona State University (Publisher)
Created2013
Description
Ephemeral streams in Arizona that are perpendicularly intersected by the Central Arizona Project (CAP) canal have been altered due to partial or complete damming of the stream channel. The dammed upstream channels have experienced decades long cycles of sediment deposition and waterlogging during storm events causing the development of "green-up" zones. This dissertation examines the biogeomorphological effects of damming ephemeral streams caused by the CAP canal by investigating: (1) changes in the preexisting spatial cover of riparian vegetation and how these changes are affected by stream geometry; (2) green-up initiation and evolution; and (3) changes in plant species and community level changes. To the author's knowledge, this is the only study that undertakes an interdisciplinary approach to understanding the environmental responses to anthropogenically-altered ephemeral stream channels. The results presented herein show that vegetation along the upstream section increased by an average of 200,872 m2 per kilometer of the CAP canal over a 28 year period. Vegetation growth was compared to channel widths which share a quasi-linear relationship. Remote sensing analysis of Landsat TM images using an object-oriented approach shows that riparian vegetation cover gradually increased over 28 years. Field studies reveal that the increases in vegetation are attributed to the artificial rise in local base-level upstream created by the canal, which causes water to spill laterally onto the desert floor. Vegetation within the green-up zone varies considerably in comparison to pre-canal construction. Changes are most notable in vegetation community shifts and abundance. The wettest section of the green-up zone contains the greatest density of woody plant stems, the greatest vegetation volume, and a high percentage of herbaceous cover. Vegetation within wetter zones changed from a tree-shrub to a predominantly tree-herb assemblage, whereas desert shrubs located in zones with intermediate moisture have developed larger stems. Results from this study lend valuable insight to green-up processes associated with damming ephemeral streams, which can be applied to planning future canal or dam projects in drylands. Also, understanding the development of the green-up zones provide awareness to potentially avoiding flood damage to infrastructure that may be unknowingly constructed within the slow-growing green-up zone.
ContributorsHamdan, Abeer (Author) / Schmeeckle, Mark (Thesis advisor) / Myint, Soe (Thesis advisor) / Dorn, Ronald (Committee member) / Stromberg, Juliet (Committee member) / Arizona State University (Publisher)
Created2014
Description
Human endeavors move 7x more volume of earth than the world’s rivers accelerating the removal of Earth’s soil surface. Measuring anthropogenic acceleration of soil erosion requires knowledge of natural rates through the study of 10Be, but same-watershed comparisons between anthropogenically-accelerated and natural erosion rates do not exist for urbanizing watersheds. Here I show that urban sprawl from 1989 to 2013 accelerated soil erosion between 1.3x and 15x above natural rates for different urbanizing watersheds in the metropolitan Phoenix region, Sonoran Desert, USA, and that statistical modeling a century of urban sprawl indicates an acceleration of only 2.7x for the Phoenix region. Based on studies of urbanization’s erosive effects, and studies comparing other land-use changes to natural erosion rates, we expected a greater degree of urban acceleration. Given that continued urban expansion will add a new city of a million every five days until 2050, given the potential importance of urban soils for absorbing anthropogenically-released carbon, and given the role of urban-sourced pollution, quantifying urbanization’s acceleration of natural erosion in other urban settings could reveal important regional patterns. For example, a comparison of urban watersheds to nearby non-urban watersheds suggests that the Phoenix case study is on the low-end of the urban acceleration factor. This new insight into the urban acceleration of soil erosion in metropolitan Phoenix can help reduce the acute risk of flooding for many rapidly urbanizing desert cities around the globe. To reduce this risk, properly engineered Flood Control Structures must account for sediment accumulation as well as flood waters. While the Phoenix area used regional data from non-urban, non-desert watersheds to generate sediment yield rates, this research presents a new analysis of empirical data for the Phoenix metropolitan region, where two regression models provide estimates of a more realistic sediment accumulation for arid regions and also urbanization of a desert cities. The new model can be used to predict the realistic sediment accumulation for helping provide data where few data exists in parts of arid Africa, southwest Asia, and India.
ContributorsJeong, Ara (Author) / Dorn, Ronald I. (Thesis advisor) / Schmeeckle, Mark (Committee member) / Walker, Ian J. (Committee member) / Arizona State University (Publisher)
Created2019
Description
The El Niño Southern Oscillation (ENSO) consists of a linkage between changes in sea-surface temperatures and atmospheric pressure across the Tropical Pacific. ENSO encompasses three phases: neutral events, warm/El Niño events in which sea-surface temperatures are warmer-than-normal and the pressure gradient decreases across the Equatorial Pacific, and cold/La Niña events in which Tropical Pacific sea-surface temperatures are cooler-than-normal and the pressure gradient increases. Previous studies have determined a connection between variations in ENSO phase and weather patterns across the globe, focusing particularly on surface temperature and precipitation patterns in the United States. However, little research exists that attempts to link changes in ENSO phase with severe weather in Arizona. Therefore, in this study, I analyzed how variations in ENSO phase affect the frequency, intensity, and spatial distribution of four types of severe weather from 1959 to 2016 in Arizona, including a) tornado events, b) severe thunderstorm wind events, c) hail events, and d) heavy rain and flash flood events. I collected data on the Oceanic Niño Index (ONI), a measure of ENSO, as well as storm reports for each severe weather phenomenon dating back to 1959. Then, I analyzed the frequency of each Arizona severe weather event type within each of the twelve annual months and over the entire study period. I also analyzed mean intensity values (Fujita/Enhanced Fujita Scale rating, path width, and path length for tornadoes; hail diameter in millimeters for hail; and wind gust speed for severe thunderstorm wind events) for each severe weather phenomenon, excluding the heavy rain and flash flood events. Finally, I used the Mean Center and Directional Distribution tools in ArcGIS to determine variations in the spatial distribution and mean centers between each ENSO phase for each severe weather event type. I found that ENSO phase, particularly La Niña, does impact the frequency and intensity of tornadoes, hail, thunderstorm wind, and heavy rain/flash flood events in Arizona. However, it appears that ENSO does not affect the spatial distribution of these Arizona severe weather phenomena. These findings attempt to fill in the gap in the literature and could help meteorologists better forecast changes in Arizona severe weather, in turn allowing Arizonans to better prepare for and mitigate the effects of severe weather across the state.
ContributorsGreenwood, Trey Austin (Author) / Cerveny, Randall (Thesis director) / Balling, Robert (Committee member) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Food’s implication on culture and agriculture challenges agriculture’s identity in the age of the city. As architect and author Carolyn Steel explained, “we live in a world shaped by food, and if we realize that, we can use food as a powerful tool — a conceptual tool, design tool, to shape the world differently. It triggers a new way of thinking about the problem, recognizing that food is not a commodity; it is life, it is culture, it’s us. It’s how we evolved.” If the passage of food culture is dependent upon the capacity for learning and transmitting knowledge to succeeding generations, the learning environments should reflect this tenability in its systematic and architectural approach.
Through an investigation of agriculture and cuisine and its consequential influence on culture, education, and design, the following project intends to reconceptualize the learning environment in order facilitate place-based practices. Challenging our cognitive dissonant relationship with food, the design proposal establishes a food identity through an imposition of urban agriculture and culinary design onto the school environment. Working in conjunction with the New American University’s mission, the design serves as a didactic medium between food, education, and architecture in designing the way we eat.
Through an investigation of agriculture and cuisine and its consequential influence on culture, education, and design, the following project intends to reconceptualize the learning environment in order facilitate place-based practices. Challenging our cognitive dissonant relationship with food, the design proposal establishes a food identity through an imposition of urban agriculture and culinary design onto the school environment. Working in conjunction with the New American University’s mission, the design serves as a didactic medium between food, education, and architecture in designing the way we eat.
ContributorsBone, Nicole (Author) / Rocchi, Elena (Thesis director) / Hejduk, Renata (Committee member) / Robert, Moric (Committee member) / The Design School (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Protest has been both a practice of citizenship rights as well as a means of social pressure for change in the context of Mexico City's water system. This paper explores the role that citizen protest plays in the city's response to its water challenges. We use media reports of water protests to examine where protests happen and the causes associated with them. We analyze this information to illuminate socio-political issues associated with the city's water problems, such as political corruption, gentrification, as well as general power dynamics and lack of transparency between citizens, governments, and the private businesses which interact with them. We use text analysis of newspaper reports to analyze protest events in terms of the primary stimuli of water conflict, the areas within the city more prone to conflict, and the ways in which conflict and protest are used to initiate improved water management and to influence decision making to address water inequities. We found that water scarcity is the primary source of conflict, and that water scarcity is tied to new housing and commercial construction. These new constructions often disrupt water supplies and displace of minority or marginalized groups, which we denote as gentrification. The project demonstrates the intimate ties between inequities in housing and water in urban development. Key words: Conflict, protest, Mexico City, scarcity, new construction
ContributorsFlores, Shalae Alena (Author) / Eakin, Hallie C. (Thesis director) / Baeza-Castro, Andres (Committee member) / Lara-Valencia, Francisco (Committee member) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Since the start of U.S. hostilities against Iraq in 2003, International Relations scholars have begun to characterize the U.S. as potentially an empire. This is because the traditional notion of sovereignty under the Westphalian nation-state system is held as a constant in the prominent theories that govern how it is thought how nation-states interact with each other. The blatant violation of international laws and norms with impunity by the U.S. have led to a re-questioning of the true dynamics underlying this system. Some scholars have characterized the recent research as a popular fad, but most of the research is aimed at just attempting to show how the U.S. could be an empire. What the current research is missing is how the U.S. became an empire, with that analysis anchored in an historical comparison. A complete chronological review of each system in its entirety is required, with all of its components, to more fully understand these phenomena. This has required researchers to devise a new methodological process of qualitatively and quantitatively analyzing macro structures. We believe the implications of the insights that can be obtained with this new method could be of use to many fields and can generate many new hypotheses to test in the future.
ContributorsRoche, Joshua Nathan (Author) / Crittenden, Jack (Thesis director) / Walker, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Economics Program in CLAS (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Politics and Global Studies (Contributor)
Created2014-12
Description
"The Legal Adventures of Frankie and Rosie" is a creative project that explores the nontraditional format of comics to express creative nonfiction. The project is a set of 30 independent comics that focuses on two primary college-going students who are based off of the authors. The characters, Frankie and Rosie narrate their stories through dialogue. The authors use this narrative model to archive their college experience at ASU. Representing creative nonfiction through comics yields an amalgamated format that can be challenging for both the writers to produce as well as for the readers to consume. Ultimately, the project serves as an attempt to test whether or not the comic medium can stand by itself as an appropriate format to express creative nonfictional narratives without becoming a diluted combination of its purer predecessors.
ContributorsBennewitz, Dana (Co-author) / Ray, Payel (Co-author) / Martin, Thomas (Thesis director) / Scott Lynch, Jacquelyn (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Electrical Engineering Program (Contributor) / School of Social Transformation (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2015-05
Description
The humanities as a discipline have typically not used a rigid or technical method of assessment in the process of analysis. GIScience offers numerous benefits to this discipline by applying spatial analysis to rigorously understand it. Photography studios developed in the mid-19th Century as a highly popular business and emerging technology. This project was initiated by Dr. Jeremy Rowe with support from the ASU Emeritus College Research and Creative Activity and Undergraduate Research Initiative grants, and seeks to use GIS tools to understand the explosive growth of photography studios in the New York City area, specifically Manhattan and Brooklyn. Demonstrated in this project are several capabilities of the ESRI online GIS, including queries for year information, a tool showing growth over time, and a generated density map of photography studios.
ContributorsAbeln, Garrett James (Author) / Li, Wenwen (Thesis director) / Rowe, Jeremy (Committee member) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Politics and Global Studies (Contributor)
Created2015-05