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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.
1

A Metapopulation Approach to Recovery of the Five-Lined Skink Using Rehabilitated Aggregate Extraction Sites

Cameron, Melissa 03 March 2009 (has links)
Protecting existing habitat for species-at-risk is an important conservation measure; however, many populations occupy highly fragmented habitat patches to the extent that population persistence is unlikely without the creation of new habitat patches. This research examines the potential for clusters of rehabilitated aggregate extraction sites to be used as reintroduction sites for species-at-risk. Using a method combining GIS and metapopulation modeling, I evaluated the success of establishing metapopulations of the Five-Lined Skink, Eumeces fasciatus, in 137 clusters of aggregate extraction sites using three hypothetical recovery scenarios. Patch abundance and patch clustering had a significant negative effect on metapopulation extinction risk. Increasing the quality of a single patch relative to other patches of suitable quality had little effect on extinction risk and patch occupancy. Introducing all individuals into a single patch decreased extinction risk and patch occupancy. Rehabilitated aggregate sites could play a role in the protection of species-at-risk in Ontario.
2

DEVELOPMENT OF A RISK SCORING METHOD FOR WATER SECURITY CHARACTERIZATION

Banting, Cassandra 13 September 2012 (has links)
Aggregate mining in Ontario is a highly contentious landuse activity between many stakeholder groups. Land use activities, within a watershed, including anthropogenic infrastructure and anthropogenic changes to the natural infrastructure (such as aggregate pits and quarries), may increase susceptibility of an aquifer by modifying contaminant migration pathways, which is an issue of water security. The purpose of this research is to apply the Vulnerability Scoring Tool to test its utility in the field of water security. The methodology is applied to an aggregate extraction site in the Grand River Watershed in Ontario, and presents an example of how changing land use may change exposure pathways. In particular, the case study results indicate an increase in vulnerability once the aquitard had been penetrated, through aggregate excavation. Applying vulnerability and risk models to future aggregate mining sites can be a useful decision-making tool when investigating impacts of aggregate extraction sites on water security. / Canadian Water Network

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