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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.
111

Adaptation Preferences and Responses to Sea Level Rise and Land Loss Risk in Southern Louisiana: a Survey-based Analysis

Maina, Sandra 23 June 2014 (has links)
Currently, southern Louisiana faces extreme land loss that could reach an alarming rate of about one football sized swath of land every hour. The combined effect of land subsidence and predicted sea level rise threaten the culture and livelihood of the residents living in this region. As the most vulnerable coastal population in Louisiana, the communities of south Terrebonne Parish are called to adapt by accommodating, protecting, or retreating from the impacts of climate change. For effective preparation planning, the state of Louisiana needs to 1) understand the adaptation preferences and responses of these residents and 2) involve these vulnerable communities in adaptation related decision making. The study uses a survey-based methodology to analyze current adaptation preferences. Findings suggest that protection is the preferred adaptation response. The present study additionally uses participatory techniques to develop a land loss awareness mobile application to illustrate the importance and benefits of community collaboration.
112

Geographical Literacy, Attitudes, and Experiences of Freshman Students: A Qualitative Study at Florida International University

Ottati, Daniela F 27 March 2015 (has links)
The purpose of the study was to explore the geography literacy, attitudes and experiences of Florida International University (FIU) freshman students scoring at the low and high ends of a geography literacy survey. The Geography Literacy and ABC Models formed the conceptual framework. Participants were freshman students enrolled in the Finite Math course at FIU. Since it is assumed that students who perform poorly on geography assessments do not have an interest in the subject, testing and interviewing students allowed the researcher to explore the assumption. In Phase I, participants completed the Geography Literacy Survey (GLS) with items taken from the 2010 NAEP Geography Subject Area Assessment. The low 35% and high 20% performers were invited for Phase II, which consisted of semi-structured interviews. A total of 187 students participated in Phase I and 12 in Phase II. The primary research question asked was what are the geography attitudes and experiences of freshman students scoring at the low and high ends of a geographical literacy survey? The students had positive attitudes regardless of how they performed on the GLS. The study included a quantitative sub-question regarding the performance of the students on the GLS. The students’ performance on the GLS was equivalent to the performance of 12th grade students from the NAEP Assessment. There were three qualitative sub-questions from which the following themes were identified: the students’ definition of geography is limited, students recall more out of school experiences with geography, and students find geography valuable. In addition, there were five emergent themes: there is a concern regarding a lack of geographical knowledge, rote memorization of geographical content is overemphasized, geographical concepts are related to other subjects, taking the high school level AP Human Geography course is powerful, and there is a need for real-world applications of geographical knowledge. The researcher offered as suggestions for practice to reposition geography in our schools to avoid misunderstandings, highlight its interconnectedness to other fields, connect the material to real world events/daily decision-making, make research projects meaningful, partner with local geographers, and offer a mandatory geography courses at all educational levels.
113

Ambivalent Landscapes: An Historical Geography of Recreation and Tourism on Mount Hood, Oregon

Mitchell, Ryan Franklin 01 June 2005 (has links)
Mount Hood is an Oregon icon. The mountain has as long and rich a history of recreation and tourism as almost any other place in the American West. But contemporary landscapes on Mount Hood reveal a recreation and tourism industry that has struggled to assert itself, and a distinct geographic divide is evident in the manner in which tourism has been developed. Why? In this study I chronicle the historical geography of recreation and tourism on Mount Hood. I examine the evolution of its character and pattern, and the ways in which various communities have used it to invest meaning in the places they call home. Despite the efforts of early boosters, Mount Hood has never been home to an elite destination resort like Aspen, Sun Valley, or Vail. Instead, modest recreation developed alongside timber and agriculture, and today the area is primarily a regional attraction. Unlike destinations with national and international clienteles that play a significant role in shaping lives and landscapes, local and regional interests are the primary drivers of recreation and tourism on Mount Hood. Communities on the mountain have incorporated the industry into their lives and landscapes to varying degrees. Mount Hood is also inextricably tied to Portland, and as an integral part of the city's history and identity, reflects its residents' tastes, values, and priorities. This combination of local and metropolitan interests has left an imprint on Mount Hood that reflects tensions and contradictions that define Oregon in the early twenty-first century: past vs. future, old vs. new economies, urban vs. rural inclinations, progress vs. status quo, and upscale vs. modest tastes. Spatially, temporally, and psychologically, Mount Hood straddles the divide between two visions: a service-based economy in the Willamette Valley, heavily dependent on technology, and a traditional, resource-based economy in much of the rest of the state.
114

Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin

Praskievicz, Sarah 01 May 2009 (has links)
Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in north western Oregon's Tualatin River Basin. The basin was chosen for this study because it is rapidly urbanizing and representative of other low-elevation basins in the region. BASINS models were calibrated and validated using historic flow and water quality data from 1991 to 2006. The goodness-of-fit for the calibrated hydrology, suspended sediment, and orthophosphate models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of ten percent, decreases in summer flows of thirty-seven percent, and increases in fifth percentile flows of up to eighty percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of twenty-one percent for the development-oriented scenario and a decrease of sixteen percent for the conservation-oriented scenario, with amplified changes at the sub-basin scale, including more than doubled winter flow. For combined scenarios of climate change and urban development, there is a projected increase in winter flows of up to seventy-one percent and decrease in summer flows of up to forty-eight percent. Changes in suspended sediment and orthophosphate loading broadly tracked hydrological changes, with winter increases and summer decreases. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale.
115

An Assessment of the Impacts of Climate Change on the Upper Clackamas River Basin with a Distributed Hydrologic Model

Graves, David 11 August 2005 (has links)
The Pacific Northwest is dependent on seasonal snowmelt for water resources that support a significant portion of its economy. Increased temperatures resulting from higher concentrations of atmospheric greenhouse gases may cause disruptions to these resources because of reductions in the annual snowpack and variations of the timing of snowmelt. This study reconstructs and applies a GIS-based distributed hydrologic model at a monthly scale to assess the effects of future climate change on runoff from the Upper Clackamas River Basin (located near Portland, Oregon). Historic flow data and snow measurements are used to calibrate and test the perfonnance of the hydro logic model for a contemporary period (1971-2000), and the model is run for two future scenarios (2010-2039 and 2070-2099) using IS92 climate change scenarios from two global climate circulation models (Hadley and Canadian Centre for Climate) as inputs. The results forecast that mean peak snowpack in the study area will drop dramatically (36% to 49% by 2010-2039, and 83% to 88% by 2070-2099), resulting in earlier runoff and diminished spring and summer flows. Increases to mean winter runoff by by the 2070-2099 period vary from moderate (13.7%) to large (46.4%), depending on the changes to precipitation forecasted by the global climate circulation models. These results are similar to those of other studies in areas dependent on snowpack for seasonal runoff, but the reductions to snowpack are more severe in this study than similar studies for the entire Columbia Basin, presumably because the elevations of much of the Upper Clackamas Basin are near the current mid-winter snow line.
116

Understory Diversity and Succession on Coarse Woody Debris in a Coastal, Old-growth Forest, Oregon

Mcdonald, Shannon Lee 20 June 2013 (has links)
This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth, coastal forest. These forests are renowned for their high forest productivity, frequent wind storms, and slow log decomposition rates that produce unmatched accumulations of coarse woody debris (CWD) yet few studies have examined the relationship between CWD and understory vegetation ecology. My research addressed this topic by comparing understory plant census data between paired fallen log and forest floor sites (n=20 pairs). My objectives were to: 1) determine the influence of substrate type on community composition and diversity, and 2) examine successional pathways and species assemblage patterns on CWD in various stages of decomposition. To meet these objectives I employed non-metric multidimensional scaling (NMDS) ordinations and unsupervised cluster analyses to identify and compare community assemblages on both substrates. These methods revealed similar species diversity and evenness between log and forest floor sites with compositional differences within and between substrates corresponding to habitat availability for colonization and light and moisture gradients. My results also suggest understory successional pathways related to decay class and characterized by an initial abundance of bryophytes, forbs, and seedlings followed by woody shrubs. Understory communities developing on logs also experienced increasing diversity, evenness, and divergence from forest floor communities consistent with log decomposition. These results differ from findings for boreal forests that reveal increasing similarity between substrate communities with increasing decay class. Recommendations for future research include the employment of a more robust sample size and direct measurements of environmental variables. Additional comparator studies are also needed to confirm the effects of forest type and decomposition on the relationship between CWD and forest understory communities. This study demonstrates how fine-scale wind disturbance fosters biodiversity through the creation of CWD substrate. My results and future research are essential for the development of silvicultural models designed to promote biodiversity in PNW coastal forests.
117

Streamflow Analysis and a Comparison of Hydrologic Metrics in Urban Streams

Wood, Matthew Lawton 01 January 2012 (has links)
This study investigates the hydrologic effects of urbanization in two Portland, Oregon streams through a comparison of three hydrologic metrics. Hydrologic metrics used in this study are the mean annual runoff ratio (Qa), mean seasonal runoff ratio (Qw and Qd), and the fraction of time that streamflow exceeds the mean streamflow during the year (TQmean). Additionally, the relative change in streamflow in response to storm events was examined for two watersheds. For this investigation urban development is represented by two urbanization metrics: percent impervious and road density. Descriptive and inferential statistics were used to evaluate the relationship between the hydrologic metrics and the amount of urban development in each watershed. The effect of watershed size was also investigated using nested watersheds, with watershed size ranging from 6 km2 to 138km 2. The results indicate that annual and seasonal runoff ratios have difficulty capturing the dynamic hydrologic behavior in urban watersheds. TQmean was useful at capturing the flashy behavior of the Upper Fanno watershed, however it did not perform as well in Kelley watershed possibly due to the influence of impermeable soils and steep slopes. Unexpected values for hydrologic metrics in Lower Johnson, Sycamore and Kelley watersheds could be the result water collection systems that appear to route surface water outside of their watersheds as well as permeable soils. Storm event analysis was effective at characterizing the behavior for the selected watersheds, indicating that shorter time scales may best capture the dynamic behavior of urban watersheds.
118

Parking Regulation Strategies and Policies to Support Transit-Oriented Development

Lundergan, Ryan W. 01 January 2009 (has links) (PDF)
This thesis identifies and explores the effects that new parking strategies and policies could have on transit-oriented development (TOD) success levels. Additionally, it makes the case for TOD parking regulation reform, and is designed to educate planners and stakeholders on how to successfully and responsibly shape parking regulation in the planning and implementation process, so that land use in the region allows the synergistic provision of sustainable transportation specifically to the Boston region. Transit-Oriented Development is viewed and defined differently throughout research and literature, with its most common traits being compact, mixed use development near transit facilities and high-quality walking environments. Due to automobile dependency in the United States, developments (including TOD) are required to provide a specific level of parking to accommodate automobile usage. Excessive provision of parking decreases urban density, walkability, housing affordability, and transit ridership. In order to comply with governmental regulations and still meet TOD goals and objectives, expensive measures such as parking garages are implemented to accommodate automobile users, leading to a less affordable development and smaller profit margins for developers. An assessment of land use characteristics around transit stations, literature pertaining to TOD and current parking regulations and policies is conducted. Best practices and strategies are proposed with the overall goal of decreasing automobile-dependency and its impacts on the urban environment. Due to TOD’s heavy reliance on extensive transit systems, the focus of the study is specifically on the 101 cities and towns in the Boston metropolitan region. Somerville, MA, which contains previous transit-oriented developments and future projects in the design process, is used as a case study for transit-oriented development.
119

Species Data and Vector Modeling: Evaluating Datasets for Improved Models of Ixodes ricinus Tick Distribution in Europe Under a Changing Climate

Jones, Steven 01 December 2022 (has links)
To increase capacity for monitoring and surveillance of tick-borne diseases, publicly available tick distribution and climate change datasets are required to create accurate predictive distribution models. It is difficult, however, to assess model accuracy and utility when using incomplete datasets.  The more recent development of comprehensive tick databases for Europe and availability of climate change scenarios from multiple IPCC Assessment Reports allows for improved modeling efforts. Multiple tick datasets were combined and three climate change projections were compared by predicting current and future distributions of Ixodes ricinus ticks in Europe using the MaxEnt species distribution model. Overall, much of Europe contains suitable habitat for the Ixodes ricinus tick, both now and under future climate change projections.  Contraction of habitable areas is predicted to occur at lower latitudes and altitudes, while expansion is predicted to occur at higher altitudes in mountainous regions and the higher latitudes, primarily in northern Scandinavia.
120

Firesafe: Designing for Fire-Resilient Communities in the American West

Baitch, Brenden 01 July 2021 (has links) (PDF)
The perception that wildfires are completely preventable has caused many structures and communities to be built in locations that will inevitably experience an uncontrollable fire event, risking human lives and infrastructure. Modification of built environments into fire-adapted communities has been explored in this thesis, through multiple strategies. Central to this analysis is the idea that sustainable human developments could adopt a form of biomimicry and indigenous design informed by the adaptions of plants, animals, and native groups that endure and even thrive with regular cycles of fire. This possibility has been assessed through the scope of fire adaptation strategies available to architects, builders, and urban planners. Design decisions including the strategic placement of buildings in relation to topography, wind, vegetation type, and fuel loads has been considered. Additionally, other mechanisms for adaptation have been assessed, such as fire-retardant building materials, building form, landscaping, and the density of built form on the scale of single homes, and broader communities. The thesis identifies a typical building site, the adjacent community, the potential threats to landscape and buildings posed by wildfire, and then explores design approaches aimed at improving fire adaptability. These factors have been considered and assessed on a qualitative level and offer new recommendations for building within fire zones. These design ideas and principles can then be applied to a variety of landscapes wherein the wildfire is inevitable, thereby exploring how fire-adapted communities may be built to sustain wildfires through a myriad of methods within a range of regions.

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