Geography Commons^™

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 …

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 …

Participatory Mapping Of Tree Equity, Preferences, And Environmental Justice In Portland, Or, Katharine Vezin Gregory

Dissertations and Theses

Studies have shown that marginalized communities do not have the same access as more privileged groups to urban tree canopy cover due to historic and current processes of discrimination and disinvestment. This study explores the lived experiences, narratives, and values related to trees and greenspaces for residents of Portland, OR, through participatory mapping focus groups. It uses an environmental justice and urban political ecology framework to examine how values, lived experiences, and narratives compare for Portland residents across neighborhoods, socio-economic status, and racial or ethnic identity and how the changes that matter to residents can inform more just urban greening …

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 …

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 …

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 …

My Mountain, Your Mountain, Our Mountain: Incorporating Emotional And Sensory Experiences In Mapping Sense Of Place In Mount Hood National Forest, Alicia Ranae Milligan

Dissertations and Theses

Understanding the complex connections humans have with landscapes is necessary for successful land management and planning practices. Only within the last few decades has mapping the values of forest users been used to produce data that can be incorporated into forest planning as a means to better understand social and environmental dynamics. This research used sense of place web mapping coupled with interviews to understand forest users' emotional and sensory experiences within the Mount Hood National Forest and to improve future sense of place mapping research. Two objectives were addressed in this research: 1) develop a typology of individuals' emotions …

Forest Fire Effects On The Temporal Variability Of Landscape Snow Albedo Relative To Burn Severity, Max Gersh

Dissertations and Theses

Snow-water storage is decreasing, while forest fires are increasing in duration, size, frequency, and intensity, due to climate change. Most forest fires occur in the seasonal snow zone, altering snow mass and energy balance for many years following fire. Following forest fires, Surface snow albedo (SSA) decreases, as light absorbing particles (LAP), particularly black carbon (BC) produced in forest fires get deposited throughout the snowpack, altering snowpack energy balance driving earlier snowmelt in burned forests. While SSA decreases, landscape snow albedo (LSA) increases following fire, as more of the snow-covered surface becomes visible beneath the burned forest canopy, brightening the …

Relationship Between Image Spectroscopy Spatial Resolution And Crown Level Tree Species Classification Accuracy, Andrew Richard Fritter

Dissertations and Theses

Hyperspectral imagery has become a common remote sensing data type used in tree species classifications because of its rich spectral signals that allow the detection of the variations in canopy reflectance. While high spatial resolution hyperspectral imagery provides fine spatial resolution for discerning surface objects, it has the inherent drawbacks of expensive acquisition costs, large data sizes, and can be computationally taxing to use. This study attempts to determine a relationship between crown level tree species classification accuracy and hyperspectral spatial resolution. Future tree species classification projects can make use of this relationship by targeting a spatial resolution that best …

Climate Model Evaluation Of Atmospheric Rivers Over The Contiguous United States, Ilan González-Hirshfeld

Dissertations and Theses

Atmospheric rivers (ARs)--long corridors of intense atmospheric water vapor transport--significantly influence the hydrologic cycle and regional hydrometeorological extremes across the contiguous United States (CONUS). Ongoing and future climate change may alter AR characteristics and impacts, making confident climate model projections of future change, especially at regional scales, of critical importance. In order to better constrain uncertainty in such projections of future change, we perform a comprehensive climate model evaluation of AR climatology over the CONUS. Using an established AR detection algorithm, we evaluate the representation of ARs in historical simulations (1984-2013) from a suite of models participating in the sixth …

Projections Of Large-Scale Atmospheric Circulation Patterns And Associated Temperature And Precipitation Over The Pacific Northwest Using Cmip6 Models, Graham Patrick Taylor

Dissertations and Theses

Projections of 500 hPa geopotential height (Z500) patterns over the Pacific Northwest of North America and their associated surface temperature, precipitation, and frequency of occurrence are assessed using models from the 6th phase of the Coupled Model Intercomparison Project (CMIP6). The self-organizing maps approach is applied to reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications, version-2 (MERRA-2) to cluster daily Z500 anomalies into 12 representative patterns that span the range of historical circulation patterns. CMIP6 data for daily Z500 anomalies are mapped to each node for historical and end of century global warming experiments, and the resulting …

Rowing Concerns: Collaborative Governance And Stakeholder Determination In The Central Oregon's Deschutes Basin, Noel Vineyard

Dissertations and Theses

In 2019, a coalition of irrigation districts in central Oregon's Deschutes Basin submitted the Deschutes Basin Habitat Conservation Plan to the US Department of Fish and Wildlife. This Habitat Conservation Plan purported to have been constructed through a collaborative governance structure between the irrigation districts and various community stakeholders who all had interests in basin management, however segments of the Basin's river recreation community began to raise concerns that their voices were not included. The purpose of this research was to investigate how stakeholder status in the Deschutes Basin is created through collaborative water governance processes like development of the …

Portland Urban Coyote Project: A Review Of Citizen Science's Utility For Researching Urban Canids And The Human Environment, Keith David Vanderbrooke

Dissertations and Theses

The Portland Urban Coyote Project (PUCP) is a citizen science project that allows community members to upload coyote (Canis latrans) sighting data to a database that is used to create a public web map; contributors often add observations as well. I analyzed one year of PUCP comment data in order to assess the utility of the citizen science methods used by PUCP for urban carnivore research. I code and summarize findings from PUCP's data, compare the extracted data to other research studies of urban coyote from other regions, and find that results from this analysis supports conclusions made …

Climatic Controls On The Kinematics Of The Hooskanaden Landslide, Curry County, Oregon, Kara Kingen

Dissertations and Theses

Slow-moving earthflows represent major sources of sediment transport and erosion and are problematic for the management of critical infrastructure. The Hooskanaden Landslide -- a slow-moving earthflow on the southwest coast of Oregon -- crosses US Highway 101 and has been a site of continued interest to the Oregon Department of Transportation (ODOT) due to the weak lithology, erosive environment, and recurrent surge behavior (every ~15 years). Past surges, including the most recent (2019), have occurred during the winter, suggesting that velocity changes are predominantly controlled by climatic inputs. To examine the response of the Hooskanaden Landslide to seasonal and other …

Evaluation Of Manual And Semi-Automated Deep-Seated Landslide Inventory Processes: Willapa Hills, Washington, Tiffany E. Justice

Dissertations and Theses

Recent advances in remote sensing data and technology have allowed for computational models to be designed that successfully extract landforms from the landscape. The goal of this work is to create one such semi-automated model to extract deep-seated landslides located in complex geomorphic terrain. This is accomplished using geographic object-based image analysis (GEOBIA) techniques, considered by leaders in the field of image analysis to have an advantage over traditional automated classification methods. GEOBIA methods can mimic human visual interpretation by including more characteristic features used to assess the relationship between image data and the ground surface such as color reflectance …

Reassessing The Ranging Behavior Of Black-And-White Ruffed Lemurs (Varecia Variegata) In Ranomafana National Park, Madagascar, Jelisa R. Oliveras

Dissertations and Theses

This study investigates black-and-white ruffed lemur (Varecia variegata) space use and movement using autocorrelated kernel density estimation (AKDE), a new methodology available from the continuous-time movement model (ctmm) package in R. Data were collected from 24 adults and subadults (10 males, 11 females, 3 subadult males) living in two adjacent V. variegata communities at Mangevo bush camp in Ranomafana National Park, Madagascar (RNP) for 11 months (February – December 2008) to estimate annual and seasonal patterns of individual and community-level range use. Autocorrelated kernel density estimates generated in this study are compared to earlier kernel density estimates from …

Assessing Airborne Radar To Map Glacier Elevations In Alpine Terrain Including Estimated Glacier Volume Change, Bryce Allen Glenn

Dissertations and Theses

Alpine glaciers and perennial snowfields (G&PS) are important hydrologically and ecologically, providing meltwater during the hottest and driest summer periods. Climate warming shrinks these natural reservoirs while temporarily providing increased streamflow. To assess regional changes in glacier volume, from which contribution to streamflow can be estimated, I used NASA's Airborne Glacier and Ice Surface Topography Interferometer (GLISTIN). This instrument mapped the surface topography of alpine glaciers; differencing these elevations from historic elevations derived from topographic maps, volume change is calculated. GLISTIN was flown over the glacier-populated mountain ranges of the western U.S. Of the 3289 glaciers and perennial snowfields with …

Variability In Historical Fire Patterns Of A Moist Mixed-Conifer Forest In The Northern Blue Mountains Of Oregon, Laura Marie Platt

Dissertations and Theses

High variability in historical fire patterns characteristic to mixed-severity fire regimes is expected to have contributed to a structurally heterogeneous landscape throughout much of the forested ecosystems of the western United States. After more than a hundred years of fire exclusion in the region, many forests have shifted to a more homogeneous structure, which raises concern regarding these forests' ability to sustain expected increases in fire activity with a warming climate. The shift is not uniform across the west, however, and differences in historical disturbance patterns and changes due to land management are not well characterized in forests across a …

A Multivariate Assessment Of Climate Change Projections Over South America Using Cmip5, Valerie Maria Thaler

Dissertations and Theses

A multivariate assessment of climate model projections over South America from the CMIP5 archive is presented. Change in near-surface temperature, precipitation, evapotranspiration, integrated water vapor transport (IVT), sea level pressure, and wind at multiple pressure levels is quantified across the multi-model suite and an assessment of model-to-model agreement on projected change performed. All models project warming by the mid- and late-21st century throughout the continent, with the highest magnitude projected over tropical regions. The CMIP5 models are in strong agreement that precipitation will decrease in all seasons over portions of Patagonia, especially along the northern portions of the current-climate mid-latitude …

Assessing Adaptive Capacity To Climate And Population Change At The Urban-Rural Interface: Human-Water System Dynamics In The Hood River Valley, Oregon, Alexander Reid Ross

Dissertations and Theses

An exurban nook on the Oregon side of the Columbia River Gorge named after the Hood River that runs northward from the glaciers of Mount Hood to the confluence seems ideally poised for the kind of relaxed, natural lifestyle that once brought suburban areas their appeal. However, like other exurban areas, Hood River also lies at an uncertain fault-line between economic and environmental transformation in the U.S.'s exurbs.

This study maps the socio-economic and climatological transformations of exurban areas as they contend with different approaches to sustainability and resilience. To determine the major climate and development hazards facing exurban areas …

Wildlife Connectivity Modeling For The Northern Red-Legged Frog In The Portland Metropolitan Area, Oregon, Amanda Hilary Temple

Dissertations and Theses

Effective habitat connectivity tools that use GIS data perform well in remote areas but may not be as dependable in urban environments. The goal was to study uses and limitations of a conservation management tool in development, the Metro Regional Habitat Connectivity Toolkit, which evaluates connectivity for and permeability of wildlife movement. Habitat quality scores are generated from GIS-derived and field collected data such as connectivity patch/matrix characteristics, water source, vegetation, other structural components, wildlife observations, and human disturbance at survey sites. I compared GIS and field generated habitat quality scores for the Northern Red-legged Frog (Rana aurora) …

Unpacking The Process And Outcomes Of Ethical Markets: A Focus On Certified B Corporations, Renée Bogin Curtis

Dissertations and Theses

The growth in conscious consumption presents an opportunity to 1) better understand the potential outcomes of ethical market practices as a community-advocacy tool and 2) to consider potential policy considerations. The marketplace has increasingly become an arena for social action. This leads to the question of how can markets facilitate ethical business practices and community benefits? The recent rise of social benefit corporations warrants an evaluation of the outcomes of ethically-driven markets. Using a comparative research design and qualitative interview methods, this study examines certified Benefit Corporations (B Corps) in two selected cities: Philadelphia and Portland. Through interviews with B …