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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.
61

A Programmatic Geographic Information Systems Analysis of Plant Hardiness Zones

Bowen, Andrew 01 May 2023 (has links) (PDF)
The Plant Hardiness Zone Map consists of thirteen geographical zones that describe whether a plant can survive based on average annual minimal temperatures. As climate change progresses, minimum temperatures in all regions are expected to change. This work programmatically evaluates predicted future climate projection data and converts it to United States Department of Agriculture-defined hardiness zones. Through the next 80 years, hardiness zones are projected to move poleward; in effect, colder zones will lose area and warmer zones will gain area globally. Some implications include changes in crop growing degree days, which could alter crop productivity, migration and settlement of invasive species over native species in shifted zones, and the interruption of plant vernalization, which is an important factor in establishing dormancy. The programmatic evaluation and analysis of hardiness zone change is a strategic lens for viewing the effects and rate of climate change using an easy-to-grasp metric.
62

Phantom Ocean, Real Impact: Natural Surf Sound Experiments Alter Foraging Activity and Habitat Use Across Taxa

Wardle, Ryan N 01 December 2020 (has links) (PDF)
A growing body of research focuses on how background sounds shape and alter critical elements of animals’ lives, such as foraging behavior, habitat use, and ecological interactions (Bradbury & Vehrencamp, 2011; Barber et al., 2010; Kight & Swaddle, 2011; Shannon et al., 2016). Much of this research has centered on the effects of anthropogenic noise (Dominoni et al., 2020; Francis & Barber, 2013; Ortega, 2012; Swaddle et al., 2015), but recent studies have also revealed that natural sound sources can influence animal behavior (Davidson et al., 2017; Le et al., 2019). Natural sounds, such as crashing surf, can create conditions where signaling and listening are difficult, but how this influences different species’ ecological interactions are unknown. To study the effects of crashing surf sound we experimentally introduced landscape-level acoustic playbacks where surf sound was not naturally present to create a “phantom ocean”. Phantom ocean treatment sites were employed alongside higher frequency “shifted” treatment sites to test for frequency-dependent effects, “real ocean” sites where surf sound was endemic, and ambient control sites. The phantom and shifted treatments were played continuously during the spring and summer of 2017-2019. Within this acoustic experimental landscape we conducted multiple studies to test the effects of crashing surf sound on animal behavior, habitat use, and ecological interactions. Through an artificial caterpillar predation experiment modeled after Roslin et al. (2017), we found that when exposed to natural sound treatments the foraging activity of rodents and arthropods increased, while that of birds declined. A potential explanation for this pattern includes taxon-specific responses reflecting different perceived risk-reward trade-offs in natural sound conditions. To follow this up we performed occupancy modeling on data collected by camera traps set within our system. We observed different responses among groups of species with different functional roles in the community for both detection (p) and occupancy (Ψ) probabilities. Our combined results indicate different species and functional groups have unique foraging behavior and patch use responses to natural sounds, likely based on their ecological interactions. Specifically, Cricetid rodents are likely more active in areas exposed to natural sounds, possibly due to lower perceived predation risk because mesocarnivores are less active. Insectivorous birds are also likely less active under natural sounds conditions, although the frequency of the sound, and the body size and diet of the bird appear influential. Together these findings suggest that natural sounds shape not only individual behavioral adjustments, but also multi-trophic, community level interactions. Our results show that natural sounds are an important driver of ecological interactions, but much remains to be uncovered. The mechanisms by which natural sounds influence individuals, populations, and many other aspects of ecology remain unexplored and provide fertile ground for future inquiry.
63

THE INFLUENCE OF HYDRODYNAMIC FORCES ON THE TRANSPORT AND RETENTION OF COLLOIDS IN SINGLE, SATURATED, DOLOMITIC LIMESTONE FRACTURES

Schutten, Michael 04 1900 (has links)
<p>Approximately 30% of Canadians and 50% of Americans rely on groundwater for their domestic water supplies. A significant portion of this groundwater originates from fractured rock aquifers, as they are ubiquitous throughout North America. In comparison to unconsolidated porous media aquifers, relatively little is understood about biocolloid transport in fractures. A mechanistic understanding of the transport and retention of biocolloids in fractures is important towards determining the risk of biocolloid contamination to these sources, which can have a significant impact on human health. It has been well documented in the interfacial science literature that micro-scale hydrodynamics play a significant role in the transport of particles greater than approximately one micron in diameter, but do not significantly affect the transport of smaller particles. This phenomenon, however, has never been investigated in fractures,where the larger-scale hydrodynamics are complex, and must also be considered. To bridge this knowledge gap, this research was conducted to elucidate the effects of hydrodynamics on the transport and retention of <em>E. coli </em>RS2GFP and carboxylate modified yellow-green polystyrene (CMP) microspheres (0.05 μm diameter) in single, saturated, fractures at the laboratory scale.</p> <p>To achieve this goal, dolomitic limestone samples were acquired from a quarry in Guelph, Ontario, and were fractured under a uniaxial force. The hydrologic properties of each fracture sample were characterized using hydraulic and solute tracer tests. Using a factorial design approach, a known number of either <em>E. coli </em>RS2-GFP or CMP microspheres was released into the fracture under a range of specific discharges (30, 10 and 5 m/day). The resulting effluent concentration profiles were compared to isolate the effects of hydrodynamics on particle transport.</p> <p>Comparing and contrasting the effluent concentration profiles from these experiments revealed that hydrodynamic forces strongly influence the retention of particles larger than 1 μm in diameter in saturated, fractured media. Additionally, the mechanisms that dominate transport and retention are dependent on, and therefore vary with both specific discharge and particle size.</p> / Master of Applied Science (MASc)
64

Exploring the impact of end-user engagement on the diffusion and adoption of a climate resilience tool in the Gulf of Mexico

Collini, Renee C 13 May 2022 (has links)
Climate change-related hazards negatively impact ecosystems, economies, and quality of life. Significant resources have been invested in data collection and research with the goal of enhanced understanding and capacity to predict future conditions in order to mitigate or adapt to intensifying hazard risk. The expansive production of climate science has generated a necessary complimentary enterprise dedicated to enhancing decision-makers’ understanding of and access to climate science as it is essential for future societal and ecological well-being. Though the aim of these many tools is to support resilient decision-making in the face of climate change, professionals report an underutilization of climate resilience tools. It has been suggested that stakeholder engagement during climate resilience tool development will improve the rates of use; however, there have been no studies to explore if the findings from tool diffusion and adoption studies in other sectors translate to climate resilience tools. An end-user engagement process for the development of a climate resilience tool was established and implemented. The process itself and the outcomes of the process, in this case an online climate decision-support tool called Gulf TREE (www.GulfTREE.org), were studied. Findings included documenting that end-user engagement during climate resilience tool development, while more costly and time intensive, does lead to increased rates of diffusion and adoption of a climate resilience tool through both direct and indirect means. This work demonstrated that pre-development engagement to scope tool development is critical for maximizing relative benefit of a climate resilience tool. Additionally, all phases of engagement are necessary for both a useable and useful tool because each phase contributes to different attributes of the tool. Further research areas identified include understanding how much and what kind of stakeholder engagement is necessary to support continued diffusion and adoption after a tool is released, the role that mandates in climate resilience has on the adoption and diffusion of climate resilience tools, and how to define if a climate resilience tool has been successful.
65

Community Perceptions of Remediation, Restoration, and Revitalization in the Great Lakes Areas of Concern

Isabelle K Staph (19194796) 24 July 2024 (has links)
<p dir="ltr">The importance of public input is increasingly recognized in the restoration of contaminated communities. Opening the decision-making process to the public allows for a wider representation of interests regarding changes being made to the community and is a vital component to successful restoration and revitalization. Over the last 50 years, the Great Lakes Areas of Concern (AOCs) have undergone remediation and restoration of contaminated waterbodies and their surrounding area to improve environmental, social, and economic conditions. Though public input is typically sought out in these projects, it is common for many people and groups within a community to be uninvolved. As opportunities for community revitalization increase, it is important to understand the community’s role in this process. There is little understanding of what public participation looks like amongst AOCs; while many have successfully engaged with the community, others are still struggling to garner interest or involvement from their community. Our research examines community perceptions of revitalization, as well as the motivators and barriers in place for the public to be involved in the overall remediation, restoration, and revitalization framework using qualitative document analysis, interviews, and a survey instrument. Our results shed light on the importance of representation and trust in community participation and how revitalization is perceived by members of the community, as well as if revitalization indicators align with community interest in Great Lakes AOCs.</p>
66

The Effects of Sediment Properties on Barrier Island Morphology and Processes: A Numerical Modeling Experiment

Kime, Brittany 20 December 2018 (has links)
Barrier island restoration and nourishment is necessary for sustaining coastal systems worldwide. In the Mississippi River Delta Plain, the lack of sediment supply, relative sea level rise, and reworking of abandoned delta lobes promote rapid disintegration of barriers, which can contribute to mainland storm impacts. Barrier island restorations that utilize higher quality sediments (Outer Continental Shelf- OCS) are expected to exhibit higher resiliency, withstanding coastal erosion, event-induced erosion, and ongoing transgression when compared to barriers nourished using lower quality nearshore (NS) sands. Additionally, use of OCS sediments increases sediment supply by adding material to the system supporting increased barrier longevity by maintaining a subaerial footprint longer compared to NS sediments. We used the Delft3D modeling suite to study barrier geomorphic trajectories nourished using OCS/NS sands, compared with control simulations with no nourishment. Resulting morphologies from 18 simulations with forcing that included annualized forcing, storms, and SLR are evaluated and compared.
67

Still Waters Run Deep: Landscaping Practices, Community Perceptions, and Social Indicators for Stormwater Nonpoint Source Pollution Management in Manatee County, Florida

Persaud, Ann Rebecca 17 March 2014 (has links)
Stormwater nonpoint source pollution (NPSP) is a result of diffuse sources of pollutants transported by rainfall and surface runoff into stormwater ponds and drainage systems before percolating into the ground. In particular, the nutrients found in fertilizers, pesticides, and herbicides applied in excess by homeowners and landscapers can cause a range of issues in stormwater ponds from fish kills to eutrophication. As a result, Manatee County, Florida has issued a fertilizer ordinance with best management practices (BMPs) and a fertilizer black out period to reduce NPSP. This study is aimed at capturing the perceptions of residents which affect stormwater NPSP through their behaviors, awareness, and knowledge. Interviews, surveys,and observational data were used to establish social indicator scores, gather qualitative data, and evaluate outreach efforts surrounding the Manatee County fertilizer ordinance and the function stormwater ponds in Lakewood Ranch. Results showed that residents substantially lacked awareness of the fertilizer ban, ordinance and grass clipping violation fine. Outreach questions revealed that 69% of residents had not seen any materials related to the ban. While residents' feelings generally ranged from neutral to positive with regard to shoreline and aquatic plants, they remained resistant to the actual installation of the plants. The results also indicated that residents were well aware of the purposes shoreline plants serving as barriers and nutrient filters. In addition, Key Informant interviews revealed that while residents understood the environmental consequences of their actions, they maintained their behavior to adhere to deeply rooted social norms.
68

Aquatic Habitat Mapping within the Obed Wild and Scenic River for Threatened and Endangered Species Habitat Delineation

Candlish, Joseph Ross 01 May 2010 (has links)
There is a need to define a more efficient and accurate approach to aquatic habitat mapping. Traditional approaches have focused on intense biological/non-biological sampling and observation analysis within specific and restrained scales. Therefore, an underwater video mapping system (UVMS) has been developed in efforts to identify federally protected aquatic species’ habitats within the Obed Wild and Scenic River (OBRI). The UVMS kayak apparatus provides georeferenced video footage correlated with GPS (global positioning systems) for GIS (geographic information systems) mapping applications. Based on its fluvial and geomorphological trends, OBRI was dissected quantitatively and integrated into databases for species-specific GIS habitat queries. Substrate type, depth, above water river characteristics (pool/riffle/run), and substrate embeddedness were extracted to access specific habitats. To better pinpoint optimal microhabitat locations, a physical habitat suitability model was developed to rank preferred habitat locales. Rankings were sequentially broken into five categories: optimal, sub-optimal, marginal, sub-marginal, and poor habitat criteria. Habitat suitability findings for the interested species habitats varied tremendously, favoring fish species. Spotfin chub, Erimonax monacha, optimal habitat was found to cover 22.14 km of river length within OBRI (30 % of OBRI’s spatial extent). The blackside dace, Phoxinus cumberlandensis, (38.9 km) and the duskytail darter, Etheostoma percnurum, (50.9 km) met optimal habitat conditions that yielded 51% and 69% of OBRI’s spatial extent, respectively. In general, optimal habitats for the six mussels were sporadically distributed and had low occurrences. Primarily, these mussel species prefer highly embedded areas with very specific depths and pool/riffle/run conditions. Cumberland elktoe, Alasmidonta atropurea, optimal habitat ranges spanned across 4.32 km (6% of OBRI’s spatial extent) with most of the habitat characteristics in OBRI being marginal. The purple bean, Villosa perpurpurea, optimal habitat was identified within 2.61 km of OBRI (3.5% of OBRI’s spatial extent). Most of the physical conditions of OBRI supplied poor to sub-marginal habitat for the purple bean, at least from a thalweg perspective. Only 385 m coincided with optimal habitat for the cumberland bean, Villosa trabalis, (0.5% of OBRI’s spatial extent) with most habitats in long sub-marginal reaches. Optimal habitats for the cumberlandian combshell, Epioblasma brevidens, the tan riffleshell, Epioblasma florentina walkeri, and the littlewing pearlymussel, Pegias fibula, were deficient, only occurring in 484 m, 276 m, and 252 m of OBRI, respectively (0.7%, 0.4%, and 0.3% of OBRI’s spatial extent). Marginal to sub-marginal habitats dominated the park for these three mussel species.
69

The Full Cost of Renewables: Managing Wind Integration Costs in California

Savage, William 13 May 2012 (has links)
Wind power will be an important component of California's aggressive strategies to meet its greenhouse gas reduction targets by the year 2020. However, the costs of integrating wind power's variable and uncertain output are often ignored. I argue that California must take prudent action to understand, minimize, and allocate wind integration costs. A review of numerous studies suggests that for wind penetration levels below 20%, integration costs should remain modest. However, costs are heavily dependent on market structure, and I suggest numerous ways that California can optimize its market design to manage wind integration costs.
70

Aquatic Habitat Mapping within the Obed Wild and Scenic River for Threatened and Endangered Species Habitat Delineation

Candlish, Joseph Ross 01 May 2010 (has links)
There is a need to define a more efficient and accurate approach to aquatic habitat mapping. Traditional approaches have focused on intense biological/non-biological sampling and observation analysis within specific and restrained scales. Therefore, an underwater video mapping system (UVMS) has been developed in efforts to identify federally protected aquatic species’ habitats within the Obed Wild and Scenic River (OBRI). The UVMS kayak apparatus provides georeferenced video footage correlated with GPS (global positioning systems) for GIS (geographic information systems) mapping applications. Based on its fluvial and geomorphological trends, OBRI was dissected quantitatively and integrated into databases for species-specific GIS habitat queries. Substrate type, depth, above water river characteristics (pool/riffle/run), and substrate embeddedness were extracted to access specific habitats. To better pinpoint optimal microhabitat locations, a physical habitat suitability model was developed to rank preferred habitat locales. Rankings were sequentially broken into five categories: optimal, sub-optimal, marginal, sub-marginal, and poor habitat criteria. Habitat suitability findings for the interested species habitats varied tremendously, favoring fish species. Spotfin chub, Erimonax monacha, optimal habitat was found to cover 22.14 km of river length within OBRI (30 % of OBRI’s spatial extent). The blackside dace, Phoxinus cumberlandensis, (38.9 km) and the duskytail darter, Etheostoma percnurum, (50.9 km) met optimal habitat conditions that yielded 51% and 69% of OBRI’s spatial extent, respectively. In general, optimal habitats for the six mussels were sporadically distributed and had low occurrences. Primarily, these mussel species prefer highly embedded areas with very specific depths and pool/riffle/run conditions. Cumberland elktoe, Alasmidonta atropurea, optimal habitat ranges spanned across 4.32 km (6% of OBRI’s spatial extent) with most of the habitat characteristics in OBRI being marginal. The purple bean, Villosa perpurpurea, optimal habitat was identified within 2.61 km of OBRI (3.5% of OBRI’s spatial extent). Most of the physical conditions of OBRI supplied poor to sub-marginal habitat for the purple bean, at least from a thalweg perspective. Only 385 m coincided with optimal habitat for the cumberland bean, Villosa trabalis, (0.5% of OBRI’s spatial extent) with most habitats in long sub-marginal reaches. Optimal habitats for the cumberlandian combshell, Epioblasma brevidens, the tan riffleshell, Epioblasma florentina walkeri, and the littlewing pearlymussel, Pegias fibula, were deficient, only occurring in 484 m, 276 m, and 252 m of OBRI, respectively (0.7%, 0.4%, and 0.3% of OBRI’s spatial extent). Marginal to sub-marginal habitats dominated the park for these three mussel species.

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