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- Genre: Academic theses
- Creators: Arizona State University
- Status: Published
Description
Environmental change and natural hazards represent a challenge for sustainable development. By disrupting livelihoods and causing billions of dollars in damages, disasters can undo many decades of development. Development, on the other hand, can actually increase vulnerability to disasters by depleting environmental resources and marginalizing the poorest. Big disasters and big cities get the most attention from the media and academia. The vulnerabilities and capabilities of small cities have not been explored adequately in academic research, and while some cities in developed countries have begun to initiate mitigation and adaptation responses to environmental change, most cities in developing countries have not. In this thesis I explore the vulnerability to flooding of the US-Mexico border by using the cities of Nogales, Arizona, USA and Nogales, Sonora, Mexico as a case study. I ask the following questions: What is the spatial distribution of vulnerability, and what is the role of the border in increasing or decreasing vulnerability? What kind of coordination should occur among local institutions to address flooding in the cities? I use a Geographic Information System to analyze the spatial distribution of flood events and the socio-economic characteristics of both cities. The result is an index that estimates flood vulnerability using a set of indicators that are comparable between cities on both sides of the border. I interviewed planners and local government officials to validate the vulnerability model and to assess collaboration efforts between the cities. This research contributes to our understanding of vulnerability and sustainability in two ways: (1) it provides a framework for assessing and comparing vulnerabilities at the city level between nations, overcoming issues of data incompatibility, and (2) it highlights the institutional arrangements of border cities and how they affect vulnerability.
ContributorsMárquez Reyes, Bernardo J (Author) / Eakin, Hallie (Thesis advisor) / Lara-Valencia, Francisco (Thesis advisor) / Aggarwal, Rimjhim (Committee member) / Arizona State University (Publisher)
Created2010
Description
Rivers in steep mountainous landscapes control how, where, and when signals of base-level fall are transmitted to the surrounding topography. In doing so rivers play an important role in determining landscape evolution in response to external controls of tectonics and climate. However, tectonics and climate often covary and understanding how they influence landscape evolution remains a significant challenge. The Hawaiian Islands, where tectonics are minimized but climate signals are amplified, provide an opportunity to better understand how signals of climate are recorded by landscapes. Focusing on the Hawaiian Islands, I examine (1) how variability in rock mass properties and thresholds in sediment mobility determine where waterfalls form or stall along the Nāpali coast of Kauaʻi, (2) I then extend these findings to other volcanoes to test if observed physical limits in flood size, climate, and volcano gradient can determine where waterfalls form, and (3) I explore how thresholds in river incision below waterfalls limit information about the influence of climate on river incision rates. Findings from this analysis show that waterfalls form or stall where the maximum unit stream power is at or below a critical unit stream power for bedrock river incision. Climate appears to have little effect in determining where these conditions are met but where waterfalls stall or form does record information about discharge-area scaling for global maximum observed floods. Below waterfalls the maximum incision depth for rivers on the island of Kauaʻi (which formed ~ 4-5 million years ago) is approximately proportional to the inverse square root of mean annual rainfall. Though maximum river incision depths for some of the younger volcanoes do not exhibit the same dependency on mean annual rainfall rates they are comparable to the maximum incision depths observed on Kauaʻi even though they are a quarter to one-tenth the age of Kauaʻi. Importantly, these patterns of incision can be explained by thresholds in sediment mobility as recorded by river longitudinal profiles and indicate that the Hawaiian Islands are dominated by threshold conditions where signals of climate are recorded in the topography through controls on incision depth but not incision rates.
ContributorsRaming, Logan Wren (Author) / Whipple, Kelin X (Thesis advisor) / Arrowsmith, Ramon (Committee member) / Heimsath, Arjun M. (Committee member) / DeVecchio, Duane E. (Committee member) / Schmeeckle, Mark (Committee member) / Arizona State University (Publisher)
Created2022