Geography Commons^™

From Cafes To Competitiveness: The Influence Of Amenities On Office Values And Suburban Economic Development In Portland, Or, Jihye Kang

Dissertations and Theses

This dissertation examines the spatial and economic implications of urban amenities in the formation of suburban office markets in the post-pandemic period. The research applies principles from agglomeration theory, spatial econometrics, and urban planning to analyze the statistical relationships between amenity distribution, rent formation, and location behavior across central and non-central submarkets.

The research consists of three integrated papers focused on the Portland–Vancouver–Hillsboro, OR–WA Metropolitan Statistical Area (MSA). The first paper employs spatial econometric modeling, specifically a Spatial Autoregressive Model with Autoregressive Disturbances (SARAR), to examine the relationship between proximity to cafés and office rent levels in Portland’s central business …

Perspectives Of Cannabis Farmers On Intersection Of Water Access And Cannabis Frontier Constraints In Southern Oregon, Tapiwa Malvin Chabikwa

Dissertations and Theses

Cannabis farming and use are being legalized at unprecedented levels by many states in the United States. Oregon was one of the pioneer states to legalize cannabis in 2016. Although it is legalized at the state level (in Oregon), cannabis remains illegal at the federal level. Due to the quasi-legalization of cannabis, an agricultural frontier for marijuana is unfolding. Cannabis farming in Oregon has grown as there is a market and ideal weather climate for the cannabis industry to flourish. This study seeks to understand the challenges cannabis farmers face in accessing water and the socio-economic and political constraints that …

The Effect Of Mesoscale Frontal Waves On Landfalling Atmospheric Rivers And Their Associated Precipitation Over The Green River Watershed, Washington, Joseph Michael Riedl

Dissertations and Theses

In this study, the effect of mesoscale frontal waves (MFWs) on extreme precipitation (EP) in the Upper Green River Watershed (UGRW), Washington is investigated. 205 EP days (>95th percentile) are identified in the UGRW between the years 1980 and 2021. To characterize the range of large-scale meteorological conditions associated with EP days, the self-organizing map (SOM) approach is used to cluster daily integrated water vapor transport (IVT) on EP days. To further diagnose the meteorological drivers, composites of several other diagnostic fields are constructed for each SOM node and the preceding days. Together, these results illustrate common orientations of …

The Art Of Memory: The Medieval Peutinger Map, Amber Shrewsbury

Dissertations and Theses

The Peutinger map is an enigma: a twelfth-century map of the Roman Empire, it is secular and oddly shaped, its dimensions distorted to show Rome at the center of the world. Its creator, purpose, and provenance currently remain lost to history. Long considered by classicists to be a copy of a lost Roman original, the map has not been seriously examined by medievalists, possibly because it does not adhere to the Christian "T-O" style of medieval mappaemundi.

While other scholars have focused on what the Peutinger map reflects about ancient Rome, I have chosen to explore how the Peutinger …

A Fifty-Year Assessment Of Historical Planning Processes And Green Space Distribution (1975-2025): A Case Study Of Portland, Or, Usa, Quadri Olatunbosun Taiwo

Dissertations and Theses

The Portland study examined past planning regulations and greenspace distribution over the period of fifty years, with particular attention given to neighborhood differences between invested and non-invested neighborhoods. This research utilized a mixed-methods approach through the synthesis of qualitative themes from oral narratives and archival records. Furthermore, I examined spatial greenspace using Normalized Difference Vegetation Index (NDVI) imagery. I tested the study hypothesis using the GIS Ordinary Least Squares (OLS) regression test to predict how key sociodemographic characteristics affect the provision of greenspace in non-white disinvested neighborhoods. The key findings indicated a consistent trend of inequity in greenspace, heavily shaped …

Identifying The Drivers Behind The Decline Of Douglas-Fir And True Fir Species In Sw Oregon, Alexander Bryant Bentley

Dissertations and Theses

Increased levels of Pseudotsuga menziesii (DF) and Abies species (TF) decline throughout dry forests in the Klamath Mountains and Western Cascades ecoregions have been recorded in recent years, with preliminary evidence suggesting that factors influenced by changing climatic conditions and encroachment from fire suppression policies are primarily to blame. Yet, the physiological and environmental mechanisms of drought-driven tree decline are poorly understood across biophysical and spatial gradients. Given the complex relations that drive decline, determining the degree of influence of specific drivers is difficult, creating unique challenges for modern forest management. To elucidate the most important factors driving DF and …

Urban Beavers At The Crossroads: How Ecological Knowledge, Sociodemographic, And Spatial Context Shape Public Perception And Coexistence Preferences, Matthew Guziejka

Dissertations and Theses

Urban beavers demonstrate synurbization by adapting to urban environments, offering ecological benefits such as biodiversity enhancement and flood mitigation, while also occasionally conflicting with infrastructure. This study examines how ecological knowledge, sociodemographics, and spatial context influence public perceptions and management preferences for urban beavers in the Tualatin River watershed, Oregon.

A voluntary survey of 176 participants from peri-urban areas assessed demographic characteristics, ecological knowledge, and attitudes toward management approaches. Spatial factors, such as proximity to watercourses and green spaces, were also analyzed. Logistic regression analyses were used to explore relationships between these factors and management preferences. Political orientation was significantly …

Tree-Equity And Environmental Justice Discourses Among Urban Forestry Professionals In Portland: Current Impacts And Future Implications, Axcelle Deone Bell

Dissertations and Theses

Urban tree equity is critical for addressing environmental justice and mitigating the effects of climate change in cities. This study investigates how professionals in Portland's urban forestry sector conceptualize and implement tree equity, focusing on equity and justice discourses. Through 27 semi-structured interviews with 29 professionals from government agencies and NGOs, I examine how these discourses shape decisions regarding tree planting, distribution, and maintenance, particularly in underserved communities. The analysis draws on political ecology, systems dynamics, and structuration theory to explore the systemic barriers perpetuating inequities in tree canopy distribution. The findings reveal tensions between different approaches to equity, such …

Post-Wildfire Water Quality Dynamics: A Multiscale Examination And Predictive Modeling Of Stream Temperature And Turbidity In Western U.S. Watersheds, Junjie Chen

Dissertations and Theses

Wildfires, exacerbated by climate change and human activities, pose significant threats to water-related ecosystem services in forested watersheds. This dissertation investigates the multifaceted impacts of wildfires on stream temperature and turbidity, two critical water quality parameters essential for maintaining aquatic ecosystem health and human water uses. By integrating a comprehensive literature review, empirical data analysis, and advanced machine learning techniques, this research provides a nuanced understanding of how wildfires affect hydrological processes across various temporal and spatial scales.

The findings reveal significant regional variability and the complex interplay between climatic, geographic, and anthropogenic factors. For instance, the literature review highlights …

"We're Going To Tear Up The Caldera So We Can Have An Electric Car": Competing Perceptions And Spatial Dimensions Of Open-Pit Lithium Mining In The Mcdermitt Caldera, Oregon, Elizabeth Bartholomew

Dissertations and Theses

As the world attempts to pivot away from fossil fuels and other greenhouse gas-emitting activities that fuel climate change, the proposed technological solutions all require raw materials, resources, and land; each of which have their own logistical and political dimensions. Lithium, a federally recognized critical mineral that is considered a crucial element in modern battery production, plays a vital role in decarbonizing efforts. Under the banners of national security, resource independence, and carbon mitigation goals, the United States has incentivized domestic lithium extraction, expediting exploration throughout the American West. The McDermitt Caldera, spanning from southeastern Oregon into northern Nevada, is …

Uncovering The Dynamic Nature Of Fire Refugia Across Landscapes In Oregon's Western Cascades, Alec Scott Dyer

Dissertations and Theses

With increased fire activity, the presence of fire refugia is critical to support forest resiliency and mitigate large-scale vegetation conversion, however, the persistence of fire refugia within burn perimeters over time is uncertain. This study examines the dynamic nature of fire refugia by mapping the decline in forest cover over time, identifying spatiotemporal patch- and landscape-scale patterns and the biophysical drivers of delayed mortality following the 2020 Labor Day Fires occurring in Oregon’s western Cascades. After three years post-fire, delayed mortality accounted for an additional 8.5% of forest loss (total of 24,147 hectares in all five burns) compared to pre-fire …

Regional And Landscape Scale Examination And Attribution Of Vegetation Changes To Social-Environmental System Drivers In Kazakhstan, Venkatesh Kolluru

Dissertations and Theses

Kazakhstan (KZ) experienced widespread changes in ecosystem structure and function. The country is a climate and land cover/use change “hotspot” owing to political reforms, intensified grazing, and extreme climatic events. Despite their importance, there is a lack of consensus about vegetation changes, trends, and drivers in KZ. Addressing this knowledge gap is crucial for effectively managing and restoring grassland ecosystems. However, a pressing challenge is discerning anthropogenic-driven vegetation changes from climate variability and decomposing the responses to the complex human-environmental forcings. Motivated by these challenges, I employed statistical and machine learning algorithms to detect and attribute vegetation changes to social-environmental …

In The Hot Seat: Acquiring Kernel Density Heat Map Design Guidance Through Delphi And Survey Methods, Lauren Eileen Mckinney-Wise

Dissertations and Theses

Kernel density heat maps have emerged as a new, popular thematic map type. Yet, unlike other thematic map types, little if any published guidance exists for effective heat map design. This is significant because maps are highly persuasive objects that are often utilized to communicate important information, but maps can also be misleading and misunderstood. Therefore, proper guidance for heat map creation is critical for cartographers to create maps that convey geographic information successfully.

To address this literature gap, I used a modified Delphi method and an online survey to investigate several questions, including understanding what cartographic experts think are …

Postfire Effects And Regeneration Patterns In Araucaria-Nothofagus Forests In South-Central Chile, Paola A. Arroyo-Vargas

Dissertations and Theses

Fire regime shifts due to climate and land use changes are threatening ecosystems worldwide, affecting their capacity to recover after severe wildfires. Increase of fire frequency, severity and intensity may severely affect forest ecosystems whose fire regimes have been characterized by infrequent stand-replacing fires. The temperate forests of southern South America, specifically the Andean temperate forests dominated by the conifer Araucaria araucana and the angiosperm species from Nothofagus genus, have evolved with less fire pressure, where severe wildfires may happen after decades or centuries. Recent severe and short-interval fires exacerbated by warmer and drier climate conditions have affected these forests, …

Disappeared Streams And Flood Risk In Atlanta, Georgia, Baltimore, Maryland, Phoenix, Arizona, And Portland, Oregon, Gregory Chrisopher Post

Dissertations and Theses

Many urban streams have been moved, culverted, buried, or "disappeared" as urban infrastructure was constructed. This loss of natural streams provided land for urban development, but as climate change increases the frequency and severity of extreme weather events, these disappeared stream areas could threaten homes and other infrastructure with increased flood risk. This study developed spatial data layers to identify many of these lost streams for Atlanta, Georgia, Baltimore, Maryland, and Phoenix Arizona, using historical maps to find streams previously visible that disappeared by the present day. This process used the oldest available georeferenced maps from the United States Geological …

Structure-From-Motion Derived Snow Cover In Burned Forests Of The Western Oregon Cascades, Siobhan Ciafone

Dissertations and Theses

Forest fire occurrence in the western US has increased rapidly since the 1980s, and most western US fires occur in the seasonal snow zone. Burned forests influence snow accumulation and melt patterns for years following fire, and understanding drivers of variability in snow cover across a burned landscape at the basin-scale is necessary for accurate hazard prediction and water resource forecasting. Basin-scale surveys of snowpack are possible with remote sensing, but accurate sensing methods such as Light Detection and Ranging (LiDAR) are often cost-prohibitive. In the last decade, structure-from-motion (SfM), an optical remote sensing technique, has emerged as an affordable …

A Mixed Methods Approach To Understanding The Links Between Mining, Climate Change And Selected Health Outcomes In India, Mary J. Cheruvillil

Dissertations and Theses

Despite ample evidence of the significant role that mining activities play in determining health outcomes, in India there is a dearth of comprehensive health studies that draw linkages between mining and health. The purpose of the following study is to investigate the impact of mining activities on population health in India using three different methods: ecological multivariable regression, exploratory spatial data analysis (ESDA) and content analysis of government documents using a phenomenological approach. The first aim uses the ecological multivariable regression to examine associations between mining activities and children’s malnutrition outcomes at the district level. Census data, the Demographic Health …

The Impact Of Climate Change On Selected Pnw Watersheds Through The Lens Of Western Red Cedar Habitat, Jordan T. Hamann

Dissertations and Theses

Climate change is a real phenomenon that is exacerbating existing natural processes and developing into a new normal for the planet. This change may be devastating for Pacific Northwest populations of Western Red Cedar (WRC) west of the Cascade Mountain range in the states of Oregon and Washington. WRC is a valuable tree species for reasons both economic and cultural. Dieback among WRC is following an accelerating trend. Since dieback is usually followed by tree mortality, understanding its causes and distribution is beneficial to the overall success of the species going into the future.

Through the use of ESRI's ArcGIS …

An Integrated Analysis Of Urban Sustainability In Portland: Issues, Indicators, Stakeholders, And Geospatial Assessment, Arun Kumar Pallathadka

Dissertations and Theses

This dissertation presents three individual studies that collectively explore the concept of urban sustainability. The research is grounded in the recognition that many cities worldwide are striving to achieve sustainable development, yet existing sustainability frameworks often lack comprehensive definition and consideration. Moreover, the existing sustainability frameworks and methods are often not clearly structured to allow for their replication and adaptation to meet the unique needs of diverse local settings. To address this gap, the dissertation utilizes the Social-Ecological-Technological Framework, with particular emphasis on equity, to investigate key issues in urban sustainability, such as indicators, stakeholder engagement, tradeoffs, and assessment. The …

Reconceiving The Relationship Between The Built Environment And Walking Behavior: Examining The Samples, Scales, And Methods In Travel Behavior Research, Jaime Pablo Orrego-Oñate

Dissertations and Theses

This dissertation aims to formulate a mechanism for the relationship between the urban form and walking choice that can be consistent across contexts. The motivation is the lack of concordant results in the magnitude of the environmental influence on walking choice in urban areas found in the literature. The dissertation identifies a series of limitations in previous research that could cause mixed results in the magnitudes of the association. This research elaborates an approach to overcome these limitations by proposing a mechanism of the activity density over walking modal share by controlling for trip distance distribution. The aim is an …

Arbuscular Mycorrhizal Fungi Colonization Response To Dike Removal In The Salmon River Estuary, Elinore Webb

Dissertations and Theses

Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with wetland plants and are important to the restoration of coastal estuaries. The purpose of this study was to assess the presence and colonization of arbuscular mycorrhizal fungi in Distichlis spicata from three formerly diked areas of the Salmon River Estuary to determine an initial understanding of the mycorrhizal community in tidal wetlands post-restoration. AMF were present in all four sample areas and total colonization ranged on average 39-72%. The reference site had the lowest levels of total colonization, which is contrary to the findings of studies of younger wetland restorations. Most importantly, …

Efficiency In The Upper Deschutes Basin: Understanding The Hydrosocial Implications Of Irrigation Canal Piping, Rebecca Anderson

Dissertations and Theses

In response to water scarcity, irrigation efficiency projects aim to conserve water for in-stream flow and agricultural use. Piping irrigation canals is a common irrigation efficiency method which reduces the loss of incidental recharge, resulting in trade-offs within a hydrosocial system. Few studies have focused on the consequences of canal piping and none have integrated a critical analysis of the social factors involved in deciding what constitutes 'efficient' water use. This study seeks to fill this gap by combining natural and social science to give attention to the scales and perspectives involved in irrigation efficiency canal piping and the material …

Erasure Through Engagement: The Community Resettlement Of Isle De Jean Charles, Meghan Elizabeth Sullivan

Dissertations and Theses

The State of Louisiana and the national media have claimed that the community resettlement of Isle de Jean Charles (IDJC) is an example of a 'model resettlement' for communities experiencing the impacts of climate change. At the outset, the project was advocated and led by the tribal leadership of the Isle de Jean Charles Band of the Biloxi-Chitimacha-Choctaw Tribe. Although, through the course of the resettlement the supposed partnership between the State of Louisiana and the Tribe has dissolved. This study seeks to provide a robust and in-depth understanding of the planning and implementation process of the IDJC resettlement to …

"We've Created Cheap Energy Off The Backs Of Salmon": Dam Removal Politics And Alliances In The Lower Snake River Basin, Krista Harrington

Dissertations and Theses

Dams, once considered by many to be good for water development in the Western U.S., might not be a part of a climate resilient future. Dams have come under increasing scrutiny due to undesirable ecological implications. Although dam removal proposals are growingly popular in recent decades, they are controversial since they impact different stakeholders in different ways. In the Pacific Northwest, the Lower four Snake River dams have long been criticized for their negative impacts on salmon. In February 2021, US Congressman Mike Simpson (R-Idaho) proposed a comprehensive framework to deconstruct the Lower four Snake River dams as an attempt …

Coming To Know The Local Environment: Children's Experiences In Rautamai Gaunpalika, Nepal, Elsie Nicole Love

Dissertations and Theses

This qualitative research, conducted over three months from late monsoon season into early fall of 2018 with twenty-six children and thirteen adults, explores how children in the hills of Rautamai Gaunpalika, Province 1, Nepal come to know their local environment. Semi-structured interviews with children, their family members, and teachers, and participant observation with children as they worked and played in forests, fields, and streams, suggest that outside of school, children come to know their local environment in the following ways: through participation in and application of knowledge to subsistence practices; through collaborative learning and teaching in mixed-age groups; through relationships …

Spatial And Seasonal Variations Of Microplastic Concentrations In Portland's Freshwater Ecosystems, Rebecca Talbot

Dissertations and Theses

Microplastics are a pollutant of growing concern and are ubiquitous in a variety of environmental compartments. The majority of microplastics research to date has been conducted in marine waters, and less is known regarding the sources and delivery pathways of microplastics in urban rivers. The first chapter is comprised of a review of the scientific literature regarding the spatial and temporal factors affecting global freshwater microplastic distributions and abundances. Microplastic spatial distributions are heavily influenced by anthropogenic factors, with higher concentrations reported in regions characterized by urban land cover, high population density, and wastewater treatment plant effluent. Temporal variables of …

Geographies Of Urban Unsafety: Homeless Women, Mental Maps, And Isolation, Jan Radle Roberson

Dissertations and Theses

This study explores the intersection of urban unsafety and the marginalized population of homeless women. Specifically, it investigates how homeless women identify/perceive and navigate unsafe urban space. Specific research questions include:

1. What does housing insecurity look like for an unhoused woman?

2. In what ways is mental mapping a robust tool for gathering the stories (data) of vulnerable populations such as unhoused women?

3. What does the spatialization of unsafe locations look like and are demographic groupings dissimilarly affected?

4. What are the critical reasons for unsafety identified by participants?

5. How do homeless women respond to urban unsafety; …

Assessment Of Vertical Accuracy From Uav-Lidar And Structure From Motion Point Clouds In Floodplain Terrain Mapping, Andrew Muller

Dissertations and Theses

Remote sensing technologies are being applied to a variety of uses because of the increase in access to various products (digital sensors, UAVs, software) and its ability to model relatively large areas in a short amount of time. While these new technologies are beginning to be adopted, validation of their merit in floodplain terrain mapping is lacking. The main goal of this study is to evaluate the vertical accuracy of digital elevation models (DEMs) generated with UAV-based LiDAR and Structure from Motion (SfM), also known as photographic LiDAR or PhoDAR. Airborne (manned aircraft) LiDAR has been applied to river research …

Modeling Environmental Factors Related To Drought-Induced Tree Mortality Based On Lidar And Hyperspectral Imagery, Lauren Nicole Sharwood

Dissertations and Theses

Climate change is projected to bring more frequent and prolonged droughts, causing widespread forest die-off. Identifying tree mortality over large spatial extents in response to the most recent California drought will help forest managers and conservationists understand where there may be a greater likelihood of future die-offs. In order to find more at-risk areas, this study evaluated how interacting site-specific topographic, climate, substrate, and stand characteristics mediated tree mortality in the Central Sierra Nevada during the 2012-2016 drought. The author used lidar and hyperspectral imagery provided by the National Ecological Observatory Network to identify individual dead trees using the Random …

Mapping The Publics: The Production Of Spatial Knowledge And Public Interest, Paul Thomas Manson

Dissertations and Theses

Over the past decades, calls for comprehensively managing and planning ocean resources have emerged internationally and within the United States. Central to these calls is a drive to expand coastal and marine spatial planning with a particular focus on technologically mediated public involvement. These new public involvement technologies aim, more quickly and thoroughly, to solicit and analyze public values and existing uses of the coastal and marine environments. One particular technological innovation is the use of participatory geographic information systems (PGIS). These new tools allow for stakeholders, members of the public, and planning entities to collect, visualize, and interact with …