• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 745
  • 110
  • 75
  • 34
  • 22
  • 18
  • 14
  • 12
  • 10
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • Tagged with
  • 1344
  • 259
  • 235
  • 232
  • 194
  • 159
  • 154
  • 140
  • 125
  • 117
  • 105
  • 96
  • 92
  • 90
  • 89
  • 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.
91

Urban climate adaptation as a process of organisational decision making

Taylor, Anna January 2017 (has links)
In a world that is increasingly urbanised, cities are recognised as critical sites for tackling problems of climate change, both by reducing greenhouse gas emissions and addressing the impacts of changing climate conditions. Unlike climate change mitigation, adaptation does not have one clear, commonly agreed collective goal. Governing and making decisions on climate adaptation in cities entails contestation over knowledge, values and preferences. Currently, the two dominant conceptualisations of adaptation are as cycles or pathways. Do these models adequately theorise what can be empirically observed in cities as to how climate adaptation is undertaken? Most research on urban climate adaptation emanates from the Global North, where political, scientific, economic and administrative systems are well established and well resourced. There is a dearth of empirical research from cities of the Global South contributing to the development of urban climate adaptation theory. This thesis contributes to addressing this gap in two ways. Firstly, by drawing on both conceptual and methodological resources from the field of organisational studies, notably the streams and rounds models of decision making, organisational ethnography and processual case research. Secondly, by conducting empirical case study research on three processes of city scale climate adaptation in Cape Town, South Africa, a growing city facing many development challenges where the local government began addressing climate adaptation over ten years ago. The three adaptation processes studied are: the preparation and adoption of city-wide sectoral climate adaptation plans; the creation of a City Development Strategy with climate resilience as a core goal; and the inclusion of climate change projections into stormwater masterplans. Data were gathered through interviews, participant observation, focus groups and document review, through embedded research within a formal knowledge co-production partnership between the University of Cape Town and the City of Cape Town government. Processual analysis and applied thematic analysis were used to test models of adaptation and decision making against data from the three case studies. The findings suggest that both the cycles and pathways models of climate adaptation inadequately represent the contested and contingent nature of decision making that prevail within the governance systems of cities such as Cape Town. Based on ethnographic knowledge of how Cape Town's local government undertakes climate adaptation, it is argued that the rounds model of decision making provides conceptual tools to better understand and represent how the process of climate adaptation in cities is undertaken; tools that can be used to enhance the pathways model. The study concludes that progress in adapting cities to a changing climate is currently constrained by both the problems and potential solutions or interventions being too technical for most politicians to deal with and prioritize and too political for most technical and administrative officials to design and implement. It calls for urban climate adaptation to be understood as distributed across a multitude of actors pursuing concurrent, discontinuous processes, and thereby focus needs to be on fostering collaboration and coordination, rather than fixating on single actors, policies, plans or projects.
92

Evaluation of a Water Budget Model for Use in Wetland Design

Neuhaus, Eric 02 September 2013 (has links)
Wetland ecological function greatly depends on the wetland hydrology. As a result, correctly estimating the wetland water budget, is essential to the success of created wetlands. A wetland water budget model, Wetbud, was developed by collaborators from Virginia Tech, Old Dominion University, and the Technical University of Crete for estimating wetland water budgets to assist wetland design in the Virginia Piedmont. The Wetbud model has basic and advanced modules. The basic module uses level pool routing to compute average monthly water levels. Based on the groundwater model MODFLOW, the advanced module estimates groundwater interactions and vegetative resistance to surface flows on a daily timestep. The overall goal of this research was to assess Wetbud as an uncalibrated design model for mitigation wetland water budget estimation in the Virginia Piedmont. Specific objectives were to compare predictions using the basic and advanced modules and to compare the Thornthwaite and the FAO-56 Penman-Monteith potential evapotranspiration estimation methods for the design of created wetlands. The Wetbud model was tested using data from two existing mitigation wetlands. Both modules produced reasonable results; however, the basic module did not accurately predict drawdown occurring during dry periods. Results showed that the Wetbud advanced module produced more accurate and detailed results when compared to the basic module: Nash-Sutcliffe model efficiency ratings for the advanced module ranged from to 0.44 to 0.63. Potential evapotranspiration estimates by the FAO-56 Penman Monteith method were more accurate than those from the Thornthwaite method in nearly every model scenario / Master of Science
93

Space debris : legal rules for its mitigation and perspectives on remediation

Mwabi, Christelle Tumba January 2019 (has links)
No abstract / Mini Dissertation (LLM)--University of Pretoria, 2019. / Public Law / LLM / Unrestricted
94

Effects of dead wood on arthropods in managed pine forests in Sweden

Jonsson, Stephanie January 2021 (has links)
Forests provide humans with a range of valuable ecosystem services, but current forest management practices may increase susceptibility to damage from disturbances such as pest insects. One such practise is the harvesting of residue, which decreases the amount of dead wood in the forest. Dead wood has been shown to be of importance for biodiversity and could decrease vulnerability to biotic disturbances. Sustainable forest management and conservation of biological diversity is required to maintain ecologically healthy forests. I aimed to investigate if biodiversity connected to dead wood could contribute to insect pest mitigation. I sampled ground-dwelling arthropods with pitfall traps in monoculture pine stands in Central Sweden on plots where dead wood had been either added or removed. To relate catches from pitfall traps to predation pressure of pest insects, I used plasticine model larvae to measure the attack rate. Contrary to my expectations, total arthropod abundance was higher when dead wood had been removed. Furthermore, the presence of dead wood had no effect on total arthropod diversity and diversity and abundance of predators. There was no relationship between predator catches and attack rates on plasticine model larvae. My results contradict previous findings that dead wood promotes biodiversity and pest mitigation. This highlights the need for studies targeting the more specific effects of different types of dead wood, in different types of forest stands on specific taxonomic groups and ecological processes, as results do not appear to be uniform across studies.
95

Mitigating Aquaculture Effluent through Use of Low-Grade Weirs

Flora, Corrin Lee 17 August 2013 (has links)
Water management practices to reduce mass discharge are a major point of concern for aquaculture producers. This study assessed effects of consecutive low-grade weirs on chemical retention and settling of aquaculture pond effluent in a single drainage ditch. Two control and nine treatment discharges were conducted September - October 2012. Control discharge dissolved inorganic phosphorus (DIP) load increased 154%, whereas total inorganic phosphorus (TIP), ammonia, and nitrate loads decreased (47%, 43%, and 63%, respectively). Treatment discharge nutrient loads decreased across all analytes (80% DIP, 86% TIP, 89% ammonia, 89% nitrate). However, control and treatment discharges concentrations of DIP and nitrate increased, whereas TIP and ammonia concentrations decreased. All discharges reduced total and volatile suspended solid loads 72% - 94%, with removal rates of 0.02 ± 0.01 mg/L/min total and 0.02 ± 0.001 mg/L/min volatile suspended solids. Results indicate ditches fit with low-grade weirs may be an innovative management practice.
96

A web-based application for assessing jurisdictional geospatial readiness

Lipscomb, Bailey D 06 August 2011 (has links)
Jurisdictions along the Gulf Coast are threatened by hurricanes. The effects of hurricanes are devastating, and the response and recovery efforts are crucial for saving lives and property. Geospatial technologies have been implemented in the response and recovery phases. However, the potential of geospatial technologies were not utilized due to data and capability issues. This study was implemented to design and develop a tool that would help a jurisdiction determine if it can apply geospatial technologies effectively in the response and recovery phases. This tool enables a jurisdiction to complete an assessment regarding GIS data, hardware, software, and personnel capabilities. Assessment results are scored using a weighted linear model, and scores are shown to the user. A rules-based system was built to show the jurisdiction methods for improving its score to the optimum level. This tool enables jurisdictions to diagnose geospatial readiness and make modifications that enhance response and recovery.
97

Resident stakeholder perceptions of lava flow hazard diversion strategies and protective measures for infrastructure and commercial and private property on Kīlauea and Mauna Loa volcanoes, Hawai‘i

Reeves, Ashleigh, Gregg, Christopher, Lindell, Michael K, Joyner, Timothy A, Houghton, Bruce 04 April 2018 (has links)
Decisions to interfere with the natural path of lava are constrained by geological, engineering and logistical factors; and legal, environmental and socio-cultural considerations. Lava flows erupted from several volcanoes around the world have threatened people and their property, motivating them to take actions to prevent or slow its advance by diverting the flow direction using channels, berms and explosives or obstructing the lava by quenching with water or armoring. Property to be protected has included government, public, commercial and private property ranging from cities and harbors to personal property. The earliest known attempt to influence the path of lava occurred in 1669 on Mount Etna, Italy, but more recent experience there occurred in the 1980s-90s. Several eruptions at Kīlauea and Mauna Loa volcanoes in Hawai‘i also provided abundant experience (1881, 1935, 1942, 1955, 1960 and several times during the on-going 1983- present eruption of Kīlauea). Additional experience relates to experimental tests and an untested berm on Mauna Loa. Most recently though, local businessmen on Kīlauea constructed earthen berms to protect their property and the local utility authority constructed novel protective structures around electric utility poles. Decisions to use mitigation strategies may be based on expert scientific opinion, but public opposition has been reported to alone be able to prevent lava mitigation. In 2014, public opinions about the use of traditional mitigation strategies (diversion by berms or bombing) to protect commercial and residential areas of Puna were mixed among residents, but there appeared to be no opposition to a new mitigation strategy that protected key areas of the electrical infrastructure and supply of electricity. To help understand public opinion about this and various mitigation strategies and people’s acceptance of additional risk to personal property to help protect important elements of their community, we conductied questionnaire surveys among residents on Kīlauea and Mauna Loa as part of a multi-university NSF Hazards SEES project. We evaluated crisis experience, hazard zonation, and community bondedness, in addition to socio-demographic and cultural factors, with beliefs concerning mitigation, including effectiveness of mitigation strategies for lava flows and others hazards; financial and legal considerations; and requirements for specialized knowledge, skills and cooperation.
98

Community Perceptions of Wildfire Risk and Mitigation in Colorado Springs

Caruolo, Cara Danielle 08 1900 (has links)
This research assessed wildfire mitigation and risk perceptions in two neighborhood in Colorado Springs, CO. Semi-structured interviews were used during transect walks with participants. The research compared residents' perspectives to fire personnel's knowledge.
99

Adjustments in Business Operations during the COVID-19 Pandemic: An Analysis of Natural and Cultural Resource Sites in Texas

Tamima, Salvesila 08 1900 (has links)
This research expands the theoretical concept of human adjustment to floods established by Gilbert F. White and incorporates his adjustment concept to examine the range of adjustments in business operations adopted by Texas' natural and/or cultural resources sites during the first year of the COVID-19 pandemic. This mixed-methods study consisted of an online survey with a follow-up semi-structured phone interview. The survey data was analyzed using descriptive statistics and the interview data was inductively coded for thematic analysis as well as quantitative and qualitative content analyses. Specifically, this study identifies the adjustment measures undertaken by these entities to maintain business operations while reducing the virus spread; analyses the direct and indirect factors influencing adjustment measures; examines new business opportunities that emerged from these adjustments; and evaluates whether the impact of COVID-19 on these entities varied in terms of entity characteristics. Findings indicate that cultural and/or natural resource sites implemented adjustments to maintain their fiscal stability and/or to protect human health; these serve as direct underlying motivating factors for these entities. To support these direct measures, indirect factors influenced the operations thus required adjustments such as staffing, volunteers, technology, funding, and donations. Additionally, new opportunities in business practices emerged while implementing these adjustments such as networking, maintenance, and virtual options. Across all entity types, virtual programs was a key adjustment addressing both fiscal and health concerns. From these adjustments, this study provides recommendations for cultural and/or natural resource sites to implement to improve resilience to future extreme events.
100

Multi-jurisdictional analysis of integration of climate change considerations in regulations and guidelines across 16 environmental impact assessment (EIA) regimes

Mayembe, Rose 23 March 2023 (has links) (PDF)
The contribution of the human activities to climate change is well understood. Yet integration of climate change considerations in tools designed to govern activities affecting the environment, such as Environmental Impact Assessment (EIA), remains underdeveloped and inconsistently applied. There is no clear direction on what measure of consideration is sufficient for environmental decision-making on potential impacts on the climate for proposed policies, programs, plans and projects. This research reviews progress across a range of 16 EIA regimes and outlines the potential for integration of climate change considerations in EIA. The research used a desk review of EIA literature to identify and assess regulations and guidelines that have been established to promote the integration of climate change in EIA. A typology of levels of integration was developed to guide analysis across multiple EIA regimes. The findings identify a global and growing normative expectation for climate change considerations to be integrated into EIA and describe the range of ways this is done across the regimes selected. Climate change integration in EIA is typically concerned with climate change mitigation, specifically greenhouse gas emissions from proposed developments. Fewer regimes are concerned with climate change adaptation, and in general, an integration deficit is identified for regimes where climate change is partially considered. Several challenges to integrating climate change in EIA are identified, including lack of practice guidelines and regulatory frameworks. Reflecting on the variety of approaches, the discussion extends typologies of integration in EIA to examine and provide a better understanding of substantive consideration of climate change in EIA. Examples of high integration indicate that EIA holds potential to play a substantive role in environmental governance at project level decision making affecting climate change. However, the range of examples also cautions that many domestic obstacles can militate against integration including political, socio-technical, and economic imperatives – particularly those affecting sectoral and scope exclusions. Nevertheless, developments across some regimes indicate leverage points for greater integration, including the role of EIA review to establish new precedents for the relevance of climate change to EIA. Potential future research and practice directions are identified, including development of regulations and practice guidelines, inclusion of climate change adaptation aspects, strengthening postdecision monitoring, application to all relevant sectors and activities, alignment with SEA, and integration across all stages of the EIA process.

Page generated in 0.0426 seconds