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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

Residential encroachment within suburban forests: Are Ontario municipal policies sufficient for protecting suburban forested natural areas for the long term?

McWilliam, Wendy Janine 17 October 2007 (has links)
Many natural areas and systems within urban landscapes are small or narrow. Landscape ecology studies within forested and agricultural landscapes have found that small natural areas that are protected from development or resource extraction through land use planning are significantly affected by adjacent land use changes. Some eventually lose the values for which they were protected. Studies also indicate that natural area boundary structures and functions are important determinants of the extent to which external threats affect adjacent natural areas. Few studies have empirically tested whether small or narrow urban natural areas that are protected from development through municipal land use planning are significantly affected by adjacent land use changes. However, municipal planners and forest managers are concerned that activities of residents living adjacent to the forest edge, commonly referred to as residential encroachment, may be degrading the social values, and ecological forms and functions of their woodlands. Studies have recorded evidence of human impacts within suburban forest edges, indicating that both recreation and yard-related activities are occurring and that these activities occur at significantly higher frequencies in the forest edge than in the interiors of these forests. However, no study has differentiated residential encroachment activities from those of other recreationists. In addition, although a number of municipalities have developed policies to address these activities, little is known about these policies, the extent to which they are implemented, or their effectiveness in protecting their small or narrow forested natural areas from residential encroachment activities. The principal research questions answered in this research are: 1) Do municipalities within Southern Ontario have policies for protecting natural areas from the activities of residents living adjacent to suburban forest edges? 2) To what extent are they implementing these policies? 3) What encroachment activities, if any, are occurring in Southern Ontario municipal forest edges? and 4) Are municipal boundary-related policies effective in limiting edge-resident encroachment activities? Using a mixed method approach, the research incorporates qualitative and quantitative data collection to answer these questions. The content analysis of official and secondary plans and social surveys of key informants within six Southern Ontario municipalities identify boundary-related policies for protecting municipal natural areas from residential encroachment activities. They also determine the extent to which the study municipalities implement these policies. Field studies in 40 forests within these municipalities used unobtrusive measurements of encroachment behaviour to describe encroachment activities under two implemented municipal boundary demarcation policies, and other boundary treatments The three research methods, together with a literature review, were used to determine whether Ontario municipal policies are effective in limiting edge-resident encroachment activities within municipal forest edges. The content analysis and interviews indicated that, in general, municipal policies were insufficient to address the edge-resident encroachment issue. Policies had been established, but not at a sufficiently authoritative policy level (i.e. the official plan level) to support their implementation by staff. In addition, policies were missing explicit goals, objectives and strategies to direct their implementation, and the municipalities had not integrated their disparate policy components into an integrated course of action through time and space. The municipalities were successful in implementing policies to prevent edge resident encroachment within natural areas adjacent to newly developing subdivisions. However, they had infrequently implemented their policies for preventing encroachment within natural areas adjacent to established subdivisions. Furthermore, all the municipalities were not frequently implementing their policies to remediate existing encroachments within natural areas adjacent to newly developing or established subdivisions. The unobtrusive measurement of encroachment behaviour confirmed that residential encroachment activities generated a housing effect zone of impact within municipal forest edges. The distribution of the evidence of encroachment was significantly biased to the forest border. Encroachment traces were highly prevalent within study forests, occurring in over 94% of sites and covering 26 to 50% of the sampled area. Encroachment traces were particularly intense in the first 8 metres from the forest border; but extended a mean maximum extent of 16 metres from the forest border, with 95% of the evidence of encroachment lying within 34 metres. Boundary type significantly affected the mean frequency, intensity and maximum extent of encroachment. Mean frequencies, intensities and extents of all encroachment, and of most encroachment categories, were generally higher in sites with boundary types that allowed edge residents ready access to the forest edge. Conversely, sites with boundary treatments that had barriers to entry, such as fences or grass strips, tended to have lower encroachment levels. Sites with multiple barriers, such as those with fences, grass strips and paths, tended to have the lowest mean frequencies, intensities and mean maximum extents of encroachment. While sites with implemented municipal post and fence policies had significantly lower mean frequencies, intensities and, in the case of fences extents of encroachment, they were not significantly different from those of sites under some of the boundary types not subject to municipal policies. They were also significantly higher than those of sites with fences and grass strips (with or without pathways). Sites with municipal posts had significantly lower mean intensities of encroachment than sites with other boundaries that enabled residents to enter the forest edge, and had significantly lower mean frequencies of waste disposal traces than fenced sites. Sites with fences also had significantly lower mean intensities of encroachment than sites with no boundary demarcation, or sites with fences and gates, and were particularly effective in reducing the incidence of yard extension encroachments, and mean maximum extents of encroachment. Despite the effectiveness of these boundary demarcation policies, and that of some of the other boundary treatments evaluated, none of the boundary treatments was effective in eliminating encroachment traces. A buffer of between 10 and 20 metres in width would be required to segregate the mean maximum extent of encroachment activities from sensitive forest edges, depending on the boundary demarcation policy, or type. The research concludes that current municipal policies are insufficient to meet the complexity and scope of the encroachment activities occurring. Some preventative policies have been developed and are regularly implemented within natural areas adjacent to new subdivisions. However, implemented boundary demarcation policies are insufficient to eliminate, or minimize residential encroachment. Wider more complex boundary policies that limit different types of encroachment and include elements that reduce access, spatially separate, and encourage informal residential surveillance (such as fences, grass strips and pathways) can further reduce encroachment levels. Few municipalities have established boundary demarcation policies to prevent encroachment within natural areas adjacent to established subdivisions, and study municipalities infrequently implement policies and bylaws to mitigate existing encroachments within these areas. Yet interviewees, and the results of the unobtrusive measurement of encroachment in study forest edges, indicate that encroachment activities are highly prevalent within these municipal forests. Policies at all levels, and particularly at the official plan level, are required to protect natural areas from edge resident encroachment, and other forms of post development impacts on natural areas. These policies are required to support the more rigorous enforcement of encroachment bylaws, and the negotiation, and implementation of effective buffers and boundary demarcation treatments. In consideration of these results and conclusions, the dissertation describes the implications for municipal planning policy and urban and regional planning theory, and provides recommendations for future research.
2

Residential encroachment within suburban forests: Are Ontario municipal policies sufficient for protecting suburban forested natural areas for the long term?

McWilliam, Wendy Janine 17 October 2007 (has links)
Many natural areas and systems within urban landscapes are small or narrow. Landscape ecology studies within forested and agricultural landscapes have found that small natural areas that are protected from development or resource extraction through land use planning are significantly affected by adjacent land use changes. Some eventually lose the values for which they were protected. Studies also indicate that natural area boundary structures and functions are important determinants of the extent to which external threats affect adjacent natural areas. Few studies have empirically tested whether small or narrow urban natural areas that are protected from development through municipal land use planning are significantly affected by adjacent land use changes. However, municipal planners and forest managers are concerned that activities of residents living adjacent to the forest edge, commonly referred to as residential encroachment, may be degrading the social values, and ecological forms and functions of their woodlands. Studies have recorded evidence of human impacts within suburban forest edges, indicating that both recreation and yard-related activities are occurring and that these activities occur at significantly higher frequencies in the forest edge than in the interiors of these forests. However, no study has differentiated residential encroachment activities from those of other recreationists. In addition, although a number of municipalities have developed policies to address these activities, little is known about these policies, the extent to which they are implemented, or their effectiveness in protecting their small or narrow forested natural areas from residential encroachment activities. The principal research questions answered in this research are: 1) Do municipalities within Southern Ontario have policies for protecting natural areas from the activities of residents living adjacent to suburban forest edges? 2) To what extent are they implementing these policies? 3) What encroachment activities, if any, are occurring in Southern Ontario municipal forest edges? and 4) Are municipal boundary-related policies effective in limiting edge-resident encroachment activities? Using a mixed method approach, the research incorporates qualitative and quantitative data collection to answer these questions. The content analysis of official and secondary plans and social surveys of key informants within six Southern Ontario municipalities identify boundary-related policies for protecting municipal natural areas from residential encroachment activities. They also determine the extent to which the study municipalities implement these policies. Field studies in 40 forests within these municipalities used unobtrusive measurements of encroachment behaviour to describe encroachment activities under two implemented municipal boundary demarcation policies, and other boundary treatments The three research methods, together with a literature review, were used to determine whether Ontario municipal policies are effective in limiting edge-resident encroachment activities within municipal forest edges. The content analysis and interviews indicated that, in general, municipal policies were insufficient to address the edge-resident encroachment issue. Policies had been established, but not at a sufficiently authoritative policy level (i.e. the official plan level) to support their implementation by staff. In addition, policies were missing explicit goals, objectives and strategies to direct their implementation, and the municipalities had not integrated their disparate policy components into an integrated course of action through time and space. The municipalities were successful in implementing policies to prevent edge resident encroachment within natural areas adjacent to newly developing subdivisions. However, they had infrequently implemented their policies for preventing encroachment within natural areas adjacent to established subdivisions. Furthermore, all the municipalities were not frequently implementing their policies to remediate existing encroachments within natural areas adjacent to newly developing or established subdivisions. The unobtrusive measurement of encroachment behaviour confirmed that residential encroachment activities generated a housing effect zone of impact within municipal forest edges. The distribution of the evidence of encroachment was significantly biased to the forest border. Encroachment traces were highly prevalent within study forests, occurring in over 94% of sites and covering 26 to 50% of the sampled area. Encroachment traces were particularly intense in the first 8 metres from the forest border; but extended a mean maximum extent of 16 metres from the forest border, with 95% of the evidence of encroachment lying within 34 metres. Boundary type significantly affected the mean frequency, intensity and maximum extent of encroachment. Mean frequencies, intensities and extents of all encroachment, and of most encroachment categories, were generally higher in sites with boundary types that allowed edge residents ready access to the forest edge. Conversely, sites with boundary treatments that had barriers to entry, such as fences or grass strips, tended to have lower encroachment levels. Sites with multiple barriers, such as those with fences, grass strips and paths, tended to have the lowest mean frequencies, intensities and mean maximum extents of encroachment. While sites with implemented municipal post and fence policies had significantly lower mean frequencies, intensities and, in the case of fences extents of encroachment, they were not significantly different from those of sites under some of the boundary types not subject to municipal policies. They were also significantly higher than those of sites with fences and grass strips (with or without pathways). Sites with municipal posts had significantly lower mean intensities of encroachment than sites with other boundaries that enabled residents to enter the forest edge, and had significantly lower mean frequencies of waste disposal traces than fenced sites. Sites with fences also had significantly lower mean intensities of encroachment than sites with no boundary demarcation, or sites with fences and gates, and were particularly effective in reducing the incidence of yard extension encroachments, and mean maximum extents of encroachment. Despite the effectiveness of these boundary demarcation policies, and that of some of the other boundary treatments evaluated, none of the boundary treatments was effective in eliminating encroachment traces. A buffer of between 10 and 20 metres in width would be required to segregate the mean maximum extent of encroachment activities from sensitive forest edges, depending on the boundary demarcation policy, or type. The research concludes that current municipal policies are insufficient to meet the complexity and scope of the encroachment activities occurring. Some preventative policies have been developed and are regularly implemented within natural areas adjacent to new subdivisions. However, implemented boundary demarcation policies are insufficient to eliminate, or minimize residential encroachment. Wider more complex boundary policies that limit different types of encroachment and include elements that reduce access, spatially separate, and encourage informal residential surveillance (such as fences, grass strips and pathways) can further reduce encroachment levels. Few municipalities have established boundary demarcation policies to prevent encroachment within natural areas adjacent to established subdivisions, and study municipalities infrequently implement policies and bylaws to mitigate existing encroachments within these areas. Yet interviewees, and the results of the unobtrusive measurement of encroachment in study forest edges, indicate that encroachment activities are highly prevalent within these municipal forests. Policies at all levels, and particularly at the official plan level, are required to protect natural areas from edge resident encroachment, and other forms of post development impacts on natural areas. These policies are required to support the more rigorous enforcement of encroachment bylaws, and the negotiation, and implementation of effective buffers and boundary demarcation treatments. In consideration of these results and conclusions, the dissertation describes the implications for municipal planning policy and urban and regional planning theory, and provides recommendations for future research.
3

Geochemical monitoring of soil pollution from the MWS-5 gold tailings facility on the Farm Stilfontein / Angelique Daniell

Daniell, Angelique January 2015 (has links)
The rehabilitation and restoration of degraded landscapes adjacent to gold tailings disposal facilities (TDFs) that have suffered loss of efficiency through anthropogenic forces has become a primary concern to environmental sciences and management in recent decades. Due to the lack of environmental legislation and enforcement thereof, minimal surface rehabilitation took place on the Mine Waste Solutions (MWS) No. 5 TDF prior to 1992, a commonplace occurrence in South Africa at the time. In 2000, MWS intervened and committed to the rehabilitation of the entire site with profits generated by the reprocessing (extraction of residual gold and uranium) of certain TDFs. However, the adjacent grazing land north of the MWS No. 5 TDF had already been subjected to pollution from the TDF which resulted in a pollution plume on the land. Although it has been inactive since April 2011, the pollution plume can be seen from the north-eastern corner of MWS No. 5 TDF, with a north-eastern/south-western direction on the farm Stilfontein. During dry periods, significant amounts of sulphate salts accumulate on the soil surface on the farm Stilfontein over a distance of at least 3.5 km from the TDF. The presence of sulphate salts in association with gold TDFs is highly common but not particularly common, in the chert-poor dolomites of the Oaktree Formation itself, in which the presence of sulphate salts is a rarity. The primary concern of this study was to determine both the quantitative and extent of the pollution observed on the farm Stilfontein over a period of 30 months via monthly monitoring of the different soil geochemical assessments across twelve fixed points, and quarterly interval assessments of three transect lines. In addition, the study was also concerned with the identification of potential linear structure anomalies associated with the pollution plume and weathered zones (fractures, joints and cavities) in the Oaktree Formation dolomites. These zones may be associated with, or may result in, the pollution extending over the area despite a topography as well as geological dip and strike that is adverse. These features and weathered zones create pathways for groundwater to flow and it was anticipated that, if present, these anomalies and weathered zones may be primary contributing factors to the pollution plume forming in a north-easterly direction and extending over the farm Stilfontein. The MWS No. 5 TDF has a hydraulic pressure head of approximately 40 m; the elevations of the north-eastern corner of the TDF and fixed point (FP) 8 (the farthest FP from the TDF) are 1368 m and 1360 m respectively, falling in close range of each other. It is anticipated that as the TDF material dries, the phreatic water level inside the TDF will lower; causing the pressure exerted by the hydraulic head of the TDF to lower over time, which will eventually end the pollution process on the soil. This study discusses the results of a holistic approach towards the evaluation of soil, vegetation and water pollution by utilizing soil quality parameters and indicators, geohydrology, geophysical surveys, Landscape Function Analysis (LFA) and other means of vegetation assessments. Salt accumulation on the soil surface was common in specific areas from 2010 – 2012. X ray diffraction (XRD) analyses confirmed that the salts originated from the No. 5 TDF due to the similarity in mineralogy. The pH values from the start of the 30-month monitoring period remained neutral to slightly alkaline due to the neutralising effect of the dolomitic bedrock. The electrical conductivity (EC) values of the soil decreased significantly from 2010 to 2014; during dry seasons since 2012, no sulphate salts accumulated on the soil surface. Joints, fractures and cavities were found within the bedrock dolomites which created pathways for the polluted TDF water and groundwater to flow towards the study area. It was also established that there were no adverse effects on the natural vegetation, other than encroachment by Seriphium plumosum which affected the grazing quality (overgrazed sites) of the area. It was therefore concluded that after the TDF became dormant in April 2011, the pollution plume in this area is decreasing in magnitude and severity due the lowering of the phreatic water level inside the TDF to significantly lower levels. Consequently, the decrease of the hydraulic pressure head of the TDF as well as rainwater infiltration and high percolation due to the presence of fractures, joints and cavities in the dolomites resulted in the leaching of the sulphate salts to a significant extent. It was also concluded that while there were no apparent adverse effects of the pollution on the functionality of the land, additional monitoring and maintenance would be required for at least the next five years in order to ensure the continuance of current conditions. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
4

Geochemical monitoring of soil pollution from the MWS-5 gold tailings facility on the Farm Stilfontein / Angelique Daniell

Daniell, Angelique January 2015 (has links)
The rehabilitation and restoration of degraded landscapes adjacent to gold tailings disposal facilities (TDFs) that have suffered loss of efficiency through anthropogenic forces has become a primary concern to environmental sciences and management in recent decades. Due to the lack of environmental legislation and enforcement thereof, minimal surface rehabilitation took place on the Mine Waste Solutions (MWS) No. 5 TDF prior to 1992, a commonplace occurrence in South Africa at the time. In 2000, MWS intervened and committed to the rehabilitation of the entire site with profits generated by the reprocessing (extraction of residual gold and uranium) of certain TDFs. However, the adjacent grazing land north of the MWS No. 5 TDF had already been subjected to pollution from the TDF which resulted in a pollution plume on the land. Although it has been inactive since April 2011, the pollution plume can be seen from the north-eastern corner of MWS No. 5 TDF, with a north-eastern/south-western direction on the farm Stilfontein. During dry periods, significant amounts of sulphate salts accumulate on the soil surface on the farm Stilfontein over a distance of at least 3.5 km from the TDF. The presence of sulphate salts in association with gold TDFs is highly common but not particularly common, in the chert-poor dolomites of the Oaktree Formation itself, in which the presence of sulphate salts is a rarity. The primary concern of this study was to determine both the quantitative and extent of the pollution observed on the farm Stilfontein over a period of 30 months via monthly monitoring of the different soil geochemical assessments across twelve fixed points, and quarterly interval assessments of three transect lines. In addition, the study was also concerned with the identification of potential linear structure anomalies associated with the pollution plume and weathered zones (fractures, joints and cavities) in the Oaktree Formation dolomites. These zones may be associated with, or may result in, the pollution extending over the area despite a topography as well as geological dip and strike that is adverse. These features and weathered zones create pathways for groundwater to flow and it was anticipated that, if present, these anomalies and weathered zones may be primary contributing factors to the pollution plume forming in a north-easterly direction and extending over the farm Stilfontein. The MWS No. 5 TDF has a hydraulic pressure head of approximately 40 m; the elevations of the north-eastern corner of the TDF and fixed point (FP) 8 (the farthest FP from the TDF) are 1368 m and 1360 m respectively, falling in close range of each other. It is anticipated that as the TDF material dries, the phreatic water level inside the TDF will lower; causing the pressure exerted by the hydraulic head of the TDF to lower over time, which will eventually end the pollution process on the soil. This study discusses the results of a holistic approach towards the evaluation of soil, vegetation and water pollution by utilizing soil quality parameters and indicators, geohydrology, geophysical surveys, Landscape Function Analysis (LFA) and other means of vegetation assessments. Salt accumulation on the soil surface was common in specific areas from 2010 – 2012. X ray diffraction (XRD) analyses confirmed that the salts originated from the No. 5 TDF due to the similarity in mineralogy. The pH values from the start of the 30-month monitoring period remained neutral to slightly alkaline due to the neutralising effect of the dolomitic bedrock. The electrical conductivity (EC) values of the soil decreased significantly from 2010 to 2014; during dry seasons since 2012, no sulphate salts accumulated on the soil surface. Joints, fractures and cavities were found within the bedrock dolomites which created pathways for the polluted TDF water and groundwater to flow towards the study area. It was also established that there were no adverse effects on the natural vegetation, other than encroachment by Seriphium plumosum which affected the grazing quality (overgrazed sites) of the area. It was therefore concluded that after the TDF became dormant in April 2011, the pollution plume in this area is decreasing in magnitude and severity due the lowering of the phreatic water level inside the TDF to significantly lower levels. Consequently, the decrease of the hydraulic pressure head of the TDF as well as rainwater infiltration and high percolation due to the presence of fractures, joints and cavities in the dolomites resulted in the leaching of the sulphate salts to a significant extent. It was also concluded that while there were no apparent adverse effects of the pollution on the functionality of the land, additional monitoring and maintenance would be required for at least the next five years in order to ensure the continuance of current conditions. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

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