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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

The Production of Organic Nitrates in Portland Oregon and the Columbia River Gorge

Neill, Holly Ann 08 April 2013 (has links)
This work studied the production of aerosol-phase organic nitrates in both Portland and the Columbia River Gorge (CRG). Ozone and NOx species were investigated for correlation with organic nitrate aerosol, as they function as precursors to the production of organic nitrates. These ambient gas-phase measurements were collected in the same locations as high-volume (Hi-Vol) filters samples, in an urban and rural gorge setting to investigate correlations at the origin of the pollution plume and downwind. A novel Soxhlet extraction method for Hi-Vol filters was developed based on literature and EPA standard methods. Analysis for nitrate production was done by segregating data based on times when the wind blew out of Portland and down the CRG versus times when flow was not westerly. Filters were then compared to ambient gas-phase measurements and derived NO3 radical production rates to look for trends. Wind direction had a strong influence on the concentrations of precursor molecules in the CRG. On days with a westerly wind direction into the gorge, concentrations of the measure aerosol organic nitrates were similar at both sides. This suggests some contribution of a broader regional production of organic nitrates. There was some correlation between the production rate of NO3 radicals and the measured organic nitrate aerosol, suggesting a role for NO3 + VOC production of organic nitrates that later partition to the aerosol phase. This information will better illuminate the fate of nitrogen downwind of pollution sources. The information will also help to create a better understanding of the way topography and meteorological conditions can influence the flow of pollution. Understanding the downwind oxidative chemistry that happens in the CRG would better support both pollution prevention and mitigation efforts.
102

Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary

Kidd, Sarah Ann 08 June 2017 (has links)
In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, salinity levels). How these controls influence the success of tidal wetland restoration are only partly understood, but have important implications for wetland habitat recovery. Specifically, the extent to which the existing native and non-native seed banks in tidally reconnected wetlands interact with these controls is not clear, yet the potential success of passive restoration methods depends upon this understanding. For a 54-year chronosequence of eleven tidal wetland restoration sites in the Lower Columbia River of western Oregon, USA, it was hypothesized that native plant species and soil properties would show trends approaching reference levels within 3 to 20 years post-restoration and that lower elevation wetland areas within restored sites would exhibit a greater native species abundance and similarity to reference sites, compared with restored high elevation wetland areas. Results indicated that plant species richness, soil organic matter, bulk density, pH, and salinity conditions among the restoration sites reached reference wetland ranges within 3-6 years post-tidal reconnection. The mid-low marsh elevation zones (<2.5 m) recovered native plant cover within 3-6 years post-tidal reconnection, while high marsh elevation zones (>2.5 m) remained dominated by nonnative species Phalaris arundinacea and Juncus effusus subsp. effusus. To investigate the mechanisms driving these non-native plant invasions, it was ii hypothesized that native and non-native wetland plant community distributions would be reflective both of their abundance in the seed bank and of their germination tolerance to wetland tidal flooding and salinity conditions. Using a factorial study design of three tidal conditions by three salinity levels, these hypotheses were tested in the greenhouse. Overall, non-native seeds were found to significantly outnumber native seeds in both seed banks. In the greenhouse, P. arundinacea and J. effusus were found to germinate more readily out of the seed bank under freshwater high-marsh flooding (1 hour a day) treatments as compared to oligohaline (3 ppt) mid-low marsh flooding (3-6 hours twice a day) treatments and to brackish salinity (10 ppt) treatments. Dominant native wetland species, Carex lyngbyei and Schoenoplectus lacustris, germination were not found to vary significantly among the treatments (p > 0.10). These results indicate that the salinity and flooding gradients within these restored marshes suppress germination of the non-native species in the low-mid marsh but not in the high marsh, where they are likely able to outcompete the native species due to their dominance in the seed bank. The implications of these results for passive tidal wetland restoration efforts are that both seed bank composition and species-specific tolerances to restored tidal flooding and salinity gradients are key mechanisms driving native and nonnative plant community development and resilience.
103

Contested Visions of Place: People, Power, and Perception on the Columbia's North Shore, 1805-1913

Sinclair, Donna Lynn 11 February 2004 (has links)
This is a narrative of place, of intersections between people, power, and perception of landscape. The environs of the Columbia River Gorge create a very distinct sense of place. Where once a series of three rapids - the Cascades of the Columbia - blocked industrial upriver transport, now Bonneville Dam and Locks allows smooth passage. To the north the vast 1.3 million acre Gifford Pinchot National Forest dominates the landscape. On the Columbia's banks lies the town of Stevenson, Washington, with Carson a few miles away, in a transitory ecological zone between east and west, at the forest's edge. There, community development has been manifestly influenced by human relationships to the landscape. Contested visions of place during the nineteenth century resulted in violent conflict and framed debates over place.Examining struggles over who would control access, first to the Cascades of the Columbia, and then to the timber of the Wind River Valley, provides a venue for examining power - of nature, ideas, and changing human cultures as overlapping groups imposed their views of the good life onto the landscape. As each successive group gained power, the relationships of humans to the land, and to one another, changed. By examining historic connections between river and forest, and between human communities to each, this study identifies multiple meanings of the same environment for different groups. I use a bioregional approach, exploring relationships between land, people and resources on the Columbia's north bank between 1805 and 1913. Power relations at the Cascades and in the forest were determined through conflict, negotiation, and the federal government, with the human relationship to nature influencing outcomes. Conflict often resulted from struggles over access to place, while human groups negotiated their place within the landscape. Nature privileged one group over another through disease, fire, and human perception, while the United States government co-opted place through public land laws, Indian removal, and by measuring and bounding the landscape. Who gained access to the river and forest of the Columbia's north shore, and how they did it, is the focus of this story.
104

Agricultural Management Decisions Impact Isoprene Emission and Physiology of Arundo donax, an Emerging Bioenergy Crop

Maxfield, Jason Charles 28 March 2014 (has links)
Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop.
105

A History of the Latter-Day Saints in the Columbia Basin of Central Washington 1850-1972

Jorgensen, Rick B. 01 November 2002 (has links) (PDF)
The Columbia Basin of Central Washington has a relatively recent Latter-day Saint history among the regions of the western states. Most of the sparsely populated rural areas in the west that have large concentrations of Latter-day Saints were originally established as "Mormon" settlements. The basin referred to lies between the Snake and Columbia Rivers and now has thousands of Latter-day Saints who have chosen to inhabit the historically barren land and call it their home. A brief visit or casual observance of the area leads many to question what were the major factors and characteristics leading to the twentieth century growth of The Church of Jesus Christ of Latter-day Saints in the Columbia Basin of Central Washington?
106

Sustainability and hydro development in the Columbia River Basin

Toller, Susan B. 05 1900 (has links)
This thesis examines the concept of sustainability and the implications of large-scale hydroelectric development for the sustainability of communities in the Canadian portion of the Columbia River Basin. A literature review of sustainability provides a background for discussion and a working definition of sustainability is proposed for consideration throughout the study. An overview of the Canadian experience with hydro development and its ecological, social and economic impacts provides a context within which to consider issues related to sustainability. The Columbia River Basin is the setting of a case study of sustainability and hydro development in British Columbia. The Kootenay region has been affected by extensive hydro projects since the early 1900s on the Kootenay River and most significantly by large dams built on the Columbia system as a result of the Columbia River Treaty. Communities in the Kootenays have borne a large share of the impacts of these dams. The resulting degradation of fisheries, wildlife and forests has jeopardized the integrity of the region’s resource base and its capability to enhance the quality of life of those living within the Columbia River drainage basin. Future hydroelectric planning should address the sustainability of the ecological, social and economic systems affected by this land use change and ensure that local communities are included in project decision-making. Increased awareness of the consequences of large-scale hydro projects during planning stages may enable sustainable development to occur.
107

The Columbia River's region: Politics, place and environment in the Pacific Northwest, 1933--present

Vogel, Eve, 1964- 12 1900 (has links)
xiv, 296 p. : ill. A print copy of this title is available through the UO Libraries under the call numbers: KNIGHT F853 .V64 2007 / This dissertation argues that Columbia River management and politics have been shaped ever since the New Deal by a conception of the Columbia River as the defining feature of the Pacific Northwest region. The study examines how that conception was developed, how it became institutionalized within and by a government agency, the Bonneville Power Administration, and what its impacts have been. Drawing on a mix of archival materials, published and unpublished secondary accounts, interviews, and the author's experience working on Columbia River policy, the dissertation shows that the definition of a Columbia River-centered Pacific Northwest was laid out in 1935 by the four-state Pacific Northwest Regional Planning Commission, influenced in part by a "regionalist" ideal of shared social and environmental well-being. It was institutionalized but narrowed into the federal BPA in 1937. Soon, a three-and-a-half-state Pacific Northwest consisting of Washington, Oregon, Idaho and western Montana was being knit together by shared transmission lines and uniformly inexpensive power rates, and by a federal power agency that positioned itself as a regional Chamber of Commerce. Since the Second World War, the Columbia River-centered Pacific Northwest has shaped its collective economic fortunes around exclusive regional access to BPA-provided Columbia River hydropower. But geographically distributed wealth did not end political conflict; private power companies, state governors, Native American tribes, and fish and wildlife agencies have had to be accommodated with distributions of BPA power and money. BPA-centered Columbia River management has through political conflict gradually expanded to serve wider interests, moving closer to the New Deal regionalist ideal. Yet in controversial decisions since 2000, Columbia River managers have chosen to risk wild salmon rather than breach federal Columbia River hydropower dams or allow Pacific Northwest power costs to escalate. They have done this because they have prioritized the most fundamental, and the most regional, Columbia River benefit of all: broadly shared inexpensive power. Understanding the opportunities and constraints of BPA-centered regional Columbia River management is essential in order to meet upcoming Columbia River policy challenges. / Adviser: Alexander B. Murphy
108

Sustainability and hydro development in the Columbia River Basin

Toller, Susan B. 05 1900 (has links)
This thesis examines the concept of sustainability and the implications of large-scale hydroelectric development for the sustainability of communities in the Canadian portion of the Columbia River Basin. A literature review of sustainability provides a background for discussion and a working definition of sustainability is proposed for consideration throughout the study. An overview of the Canadian experience with hydro development and its ecological, social and economic impacts provides a context within which to consider issues related to sustainability. The Columbia River Basin is the setting of a case study of sustainability and hydro development in British Columbia. The Kootenay region has been affected by extensive hydro projects since the early 1900s on the Kootenay River and most significantly by large dams built on the Columbia system as a result of the Columbia River Treaty. Communities in the Kootenays have borne a large share of the impacts of these dams. The resulting degradation of fisheries, wildlife and forests has jeopardized the integrity of the region’s resource base and its capability to enhance the quality of life of those living within the Columbia River drainage basin. Future hydroelectric planning should address the sustainability of the ecological, social and economic systems affected by this land use change and ensure that local communities are included in project decision-making. Increased awareness of the consequences of large-scale hydro projects during planning stages may enable sustainable development to occur. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate
109

Study of Prestige and Resource Control Using Fish Remains from Cathlapotle, a Plankhouse Village on the Lower Columbia River

Rosenberg, J. Shoshana 22 May 2015 (has links)
Social inequality is a trademark of Northwest Coast native societies, and the relationship between social prestige and resource control, particularly resource ownership, is an important research issue on the Northwest Coast. Faunal remains are one potential but as yet underutilized path for examining this relationship. My thesis work takes on this approach through the analysis of fish remains from the Cathlapotle archaeological site (45CL1). Cathlapotle is a large Chinookan village site located on the Lower Columbia River that was extensively excavated in the 1990s. Previous work has established prestige distinctions between houses and house compartments, making it possible to examine the relationship between prestige and the spatial distribution of fish remains. In this study, I examine whether having high prestige afforded its bearers greater access to preferred fish, utilizing comparisons of fish remains at two different levels of social organization, between and within households, to determine which social mechanisms could account for potential differences in access to fish resources. Differential access to these resources within the village could have occurred through household-level ownership of harvesting sites or control over the post-harvesting distribution of food by certain individuals. Previous work in this region on the relationship between faunal remains and prestige has relied heavily on ethnohistoric sources to determine the relative value of taxa. These sources do not provide adequate data to make detailed comparisons between all of the taxa encountered at archaeological sites, so in this study I utilize optimal foraging theory as an alternative means of determining which fish taxa were preferred. Optimal foraging theory provides a universal, quantitative analytical rule for ranking fish that I was able to apply to all of the taxa encountered at Cathlapotle. Given these rankings, which are based primarily on size, I examine the degree to which relative prestige designations of two households (Houses 1 and 4) and compartments within one of those households (House 1) are reflected in the spatial distribution of fish remains. I also offer a new method for quantifying sturgeon that utilizes specimen weight to account for differential fragmentation rates while still allowing for sturgeon abundance to be compared to the abundances of other taxa that have been quantified by number of identified specimens (NISP). Based on remains recovered from 1/4" mesh screens, comparisons between compartments within House 1 indicate that the chief and possibly other elite members of House 1 likely had some control over the distribution of fish resources within their household, taking more of the preferred sturgeon and salmon, particularly more chinook salmon, for themselves. Comparisons between households provide little evidence to support household-based ownership of fishing sites. A greater abundance of chinook salmon in the higher prestige House 1 may indicate ownership of fishing platforms at major chinook fisheries such as Willamette Falls or Cascades Rapids, but other explanations for this difference between households are possible. Analyses of a limited number of bulk samples, which were included in the study in order to examine utilization of very small fishes, provided insufficient data to allow for meaningful intrasite comparisons. These data indicate that the inhabitants of Cathlapotle were exploiting a broad fish subsistence base that included large numbers of eulachon and stickleback in addition to the larger fishes. This study provides a promising approach for examining prestige on the Northwest Coast and expanding our understanding of the dynamics between social inequality and resource access and control.
110

Regional scale sandbar variability : observations from the U.S. Pacific Northwest

Di Leonardo, Diana R. 28 November 2012 (has links)
Understanding sandbar dynamics and variability is integral to developing a predictive capacity for nearshore flows, sediment transport, morphological change, and ultimately for determining coastline exposure to damaging storm waves. Along the high-energy U.S. Pacific Northwest (PNW) coast, sandbars typically dominate the bathymetry of the active zone. Here we report on a nearshore bathymetric data set that covers an exceptionally long stretch of coast and crosses several littoral cell boundaries. Our study area stretches from Point Grenville, Washington to Cascade Head, Oregon, including 8 littoral cells and approximately 250 km in the alongshore. We describe and quantify the morphological variability of sandbars in the PNW over large spatial scales as well as attempt to explain the inter-littoral cell variability via trends and variability in environmental parameters. From 560 bathymetric profiles (~1000 km of measurements) we have extracted over 500 distinct subtidal sandbars. The bar zone extends to over 1km from the shoreline in the northern part of the study area, but only to about 600m in the southern part. Maximum bar crest depths are typically 7m below MLLW. Bar heights range from a step in the cross-shore profile to over 3m from crest to trough. The northernmost littoral cells typically have two or more bars per cross-shore profile whereas the littoral cells in the southern part of our study area have only one bar. The mean depths of the bars, however, are much more consistent across littoral cells. The mean depths remain consistent even while the upper shoreface slope significantly increases from north to south, requiring that the maximum bar distance from the shoreline decreases from north to south. This regional gradient in upper shoreface slope is likely a response, at least in part, to a general coarsening trend in the sediment from north to south and hence linked to variations in regional geology. / Graduation date: 2013

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