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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.
361

Reducing traffic in country parks

Poon, Po-wan, Shirley., 潘寶雲. January 2001 (has links)
published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning
362

A conspiracy of optimism: Sustained yield, multiple use, and intensive management on the national forests, 1945-1991.

Hirt, Paul Wayne. January 1991 (has links)
This is a historical study of the intersection of political economy with natural resources management, as played out on the national forests between 1945-1991. Specifically, it focuses on two core national forest management policies; sustained yield and multiple use. These two policy directives represent an attempt by the public and elected officials to apply principles of sustainable development to publicly-owned forest lands, and to ensure that a wide variety of both market and nonmarket forest values are preserved for the benefit of present and future generations. Interest groups, the Forest Service, and policy makers have conceived of sustained yield and multiple use in different and evolving ways over the years. This study explores how these principles have been variously defined and either implemented or thwarted. After World War Two, with escalating demands on national forest resources, the U.S. Forest Service turned to "intensive management" as a technological method of enhancing natural forest productivity and mitigating the environmental effects of increased use. But the agency's optimistic vision of efficient, sustained production of forest commodities through technical mastery over nature has met overwhelming fiscal, environmental, technical, and political obstacles. Nevertheless, agency leaders, industry advocates, and politicians have consistently promulgated an optimistic faith that intensive applications of labor, capital, and technology can maximize and harmonize multiple uses, rehabilitate damaged resources, and sustain high levels of outputs in perpetuity--despite repeated failures to achieve balanced multiple use management and to manage grazing and timber extraction at sustainable levels. The conspiracy of optimism ideologically justifies continued unsustainably high levels of resource extraction. Changing public values since the 1960s and the popularization of ecology have initiated a growing skepticism toward the premises of intensive management. At the same time, field level forest managers have grown frustrated with top-down imposition of resource production quotas and the lack of adequate political, fiscal, and organizational support for sound forest management. As the last old growth forests fall to the chainsaw, and as the federal subsidies required to access these remote timber stands on the national forests escalate, public controversy deepens. In this decade of the national forest centennial a revolt of conscience has erupted among grassroots Forest Service personnel, and a strong challenge from the environmental community has gained momentum. Another major period of policy evaluation and revision appears to be taking place. Whether the conspiracy of optimism can continue to sustain the old status quo is questionable.
363

Marine Reserves, Community-Based Management, and Small-Scale Benthic Fisheries in the Gulf of California, Mexico

Cudney-Bueno, Richard January 2007 (has links)
I address the emergence, governance, and effects of marine reserve efforts in the Gulf of California, Mexico, emphasizing a community-based marine reserve network established by the commercial diving sector of Puerto Peñasco, Sonora. This network emerged as a means to manage benthic resources in rocky reefs, primarily rock scallop (Spondylus calcifer) and black murex snail (Hexaplex nigritus). My study also provides an analysis of growth, reproductive ecology, and management of both species.I show that local cooperation to manage fisheries commons incorporating the use of marine reserves can emerge rapidly. Furthermore, this cooperation can be sustained in a fishery spanning no more than two generations, effectively avoiding a local "tragedy of the commons". A blend of social group characteristics, fishers' ecological knowledge and participation in monitoring, and relatively rapid ecological response of the system can play key roles in reinforcing cooperation.I provide evidence of rapid effects of reserves on adjacent fisheries via larvae dispersal. Visual censuses revealed that density of young rock scallop (individuals recruited since reserve establishment) had increased by up to 40.7% within coastal reserves and by 20.6% in fished sites in only two years. Changes were also evident for black murex, with more than a three-fold increase in the density of juveniles within fished sites. These effects, however, were spatially-constricted, evident only for the northern portion of the reserve network. These empirical findings are more indicative of a reserve effect rather than other confounding factors and are consistent with field oceanography data (release of satellite-tracked drifters) and outputs from larvae dispersal models.Finally, I show that just as cooperation can emerge, it can rapidly fall with cascading effects to the system's resilience, particularly amidst threats to social capital and pressure from outside the community. I conclude that even when community-based reserves are effective within the biophysical and local social context, their long-term efficacy will rely on the system's capacity to control access and will demand the institutional capacity to do so. In Mexico this implies, at the least, the government's formal recognition of community-based initiatives and a means to give viability to these efforts.
364

THE EFFECTS OF PROFESSIONAL BIAS ON PERCEPTION AND MANAGEMENT OF TWO WILDERNESSES NEAR TUCSON, ARIZONA.

Kennedy, Christina Beal. January 1985 (has links)
No description available.
365

The perception of changes in visibility at Class I Parks and Wilderness areas

Parsons, Russ, 1957- January 1987 (has links)
The language of regulations implementing the 1977 Clean Air Act Amendments distinguishes between humanly detectable visibility impairment in Class I Parks and Wilderness areas and the extent to which such impairment adversely affects a park visitor's visual experience. Two lines of environmental perception research have arisen from this distinction, one emphasizing the detectability of visibility impairment, and the other emphasizing a park visitor's experience. This study attempts to deal with issues relevant to both lines of research. Subjects were shown color slides depicting varying levels of visibility in Class I Parks and Wilderness areas under four treatment conditions. A sensitivity gradient emerged from these conditions: Subjects who rated repeated versions of selected vistas for visual air quality were most sensitive to changes in visibility, while subjects who rated a random series of scenes for scenic beauty were least sensitive. Other variables (i.e., scattering angle, and the particular vista being viewed) also proved to have substantial influence on perceptual ratings.
366

A multiple trophic level approach to assess ecological connectivity and boundary function in marine protected areas : a British Columbia example

Short, Charles Joseph. 10 April 2008 (has links)
No description available.
367

Making poverty: a history of on-reserve housing programs, 1930-1996

Olsen, Sylvia 02 May 2016 (has links)
While few people would say that Canada has done a good job of housing its poor citizens, this discussion goes beyond problems of housing the poor. In this dissertation I draw from government records to uncover how, between the 1930s and 1990s, the Indian Department created and oversaw a failed housing system on reserves across the country - one decision at a time. While housing is usually seen to be a result of poverty I argue that during this time the practices and policies of the Indian Department were active participants in making Indigenous people and First Nations communities poor. As a consequence of the persistent housing crisis on reserves in Canada Indigenous people suffered not only from living in substandard dwellings but also from the indignity and shame that comes from the association Canadians have made between the poor conditions of on-reserve housing and the personal characteristics of its occupants. What most people do not know is how it is that on-reserve housing remained in crisis for so long. On-reserve housing is something we have done not something we have studied. While federal government reports have charted the number of houses on reserves and their physical condition, no one has examined the history of government programs or how they were delivered until now. Recognizing that my study was not designed to recommend solutions, but believing that we cannot fix a problem until we know it, I am convinced that this dissertation provides the background information future academics will need to tell a different story about housing on reserves. And with a different story we will be better prepared to make fundamental changes needed to the way housing is delivered on reserves. / Graduate
368

Urban shades of green : Current patterns and future prospects of nature conservation in urban landscapes

Borgström, Sara January 2011 (has links)
Urban nature provides local ecosystem services such as absorption of air pollutants, reduction of noise, and provision of places for recreation, and is therefore crucial to urban sustainable development. Nature conservation in cities is also part of the global effort to halt biodiversity decline. Urban landscapes, however, display     distinguishing social and ecological characteristics and therefore the implementation of nature conservation frameworks into cities, requires reconsideration of what nature to preserve, for whom and where. The aim of this thesis was to examine the current urban nature conservation with special focus on formally protected areas, and discuss their future role in the urban landscape. A social-ecological systems approach was used as framework and both quantitative and qualitative methods were applied. The studies were performed at local to regional scales in the southern part of Sweden. Four key questions were addressed: i) What are the characteristics of nature conservation in urban landscapes? ii) How does establishment of nature conservation areas affect the surrounding urban landscape? iii) In what ways are spatial and temporal scales recognized in practical management of nature conservation areas? and iv) How can the dichotomy of built up and nature conservation areas be overcome in urban planning? Nature reserves in urban, compared to rural landscapes were in general fewer, but larger and included a higher diversity of land covers. They were also based on a higher number and different kinds of objectives than rural nature reserves. Urbanisation adjacent to nature reserves followed the general urbanisation patterns in the cities and no additional increase in urban settlements could be detected. In general, there was a lack of social and ecological linkages between the nature conservation areas and the urban landscape and practical management showed a limited recognition of cross-scale interactions and meso-scales. Such conceptual and physical isolation risks decreasing the public support for nature conservation, cause biodiversity decline, and hence impact the generation of ecosystem services. A major future challenge is therefore to transform current conservation strategies to become a tool where urban nature is perceived, planned and managed as valuable and integrated parts of the city. To enable social-ecological synergies, future urban planning should address proactive approaches together with key components like active enhancement of multifunctional landscapes, cross-scale strategies and border zone management. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Submitted. Paper 5: Manuscript.</p>
369

An Analysis of Smoothing of Proved Oil and Gas Reserve Quantities and an Analysis of Bias and Variability in Revisions of Previous Estimates of Proved Oil and Gas Reserve Quantities

Campbell, Alan D. 08 1900 (has links)
The purpose of this study is to determine whether oil and gas producing companies smooth their ending reserve quantities. Smoothing is defined as a reduction in variance in the trend of ending reserve quantities over time compared to the trend of ending reserve quantities less the hypothesized smoothing variable over time. This study focuses on two variables that are most susceptible to manipulation—revisions of previous estimates and additions. This study also examines whether revisions are positively or negatively biased and the variability of the revisions. The sample consists of 70 companies chosen from oil & Gas Reserve Disclosures: 1980-1984 Survey of 400 Public Companies by Arthur Andersen and Company. For each company, ending reserve quantities for the years 1978-1984 were regressed over time, and the standard deviation of the estimate (SDE) was calculated. Then the ending reserve quantities less the hypothesized smoothing variable were regressed over time, and the SDE was calculated. A linear model and a semi-logarithmic model were used. A smoothing ratio (SR) was determined by dividing the SDE of reserves less the hypothesized smoothing variable by the SDE of ending reserve quantities. An SR greater than one indicates smoothing, and an SR less than one indicates that smoothing did not occur. The mean percentage revision and a t-test were used to test for positive or negative bias in the revisions. The mean absolute percentage revision was used to assess the relative variability of revisions. The number of companies classified as smoothers of oil reserves was statistically significant for the semi-logarithmic model but not for the linear model. Under both models the number of companies classified as smoothers of gas reserves was statistically significant. Few companies had mean percentage revisions that were significantly different from zero. The majority of companies had mean absolute revisions of under ten percent.
370

Bayesovské přístupy ve stochastickém rezervování / Bayesian Approaches to Stochastic Reserving

Novotová, Simona January 2014 (has links)
In the master thesis the issue of bayesian approach to stochastic reserving is solved. Reserving problem is very discussed in insurance industry. The text introduces the basic actuarial notation and terminology and explains the bayesian inference in statistics and estimation. The main part of the thesis is framed by the description of the particular bayesian models. It is focused on the derivation of estimators for the reserves and ultimate claims. The aim of the thesis is to show the practical uses of the models and the relations between them. For this purpose the methods are applied on a real data set. Obtained results are summarized in tables and the comparison of the methods is provided. Finally the impact of a prior distribution on the resulting reserves is showed. Powered by TCPDF (www.tcpdf.org)

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