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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.
631

Strategic environmental assessment design for wetland assessment and conservation policy development in an urban planning context

2015 June 1900 (has links)
This research advances Strategic Environmental Assessment (SEA) design and methodology for wetland assessment and policy development within an urban planning context. The thesis is a ‘manuscript-style’ and consists of three manuscripts, which collectively contribute to the overarching research purpose. The first manuscript presents and demonstrates a spatial framework for the application of SEA in the context of land use change analysis for urban wetland environment. The study aims to meet the needs for a proactive framework to assess and protect wetland areas more efficiently, and advance urban planning and development design. The proposed framework, adopting Geographic Information System and Remote Sensing approaches, presents a temporal evaluation of wetland change and sustainability assessment based on landscape indicator analysis. The results show that despite the recent extremely wet period in the Canadian prairie region, land use change contributed to increasing threats to wetland sustainability in the developing urban environment of the city of Saskatoon from 1985 to 2011. The second manuscript presents a scenario-based approach to SEA for wetland trends analysis and land use and land cover (LUC) modeling. Alternative future LUC was simulated using remote sensing data and city planning documentation using a Markov chain technique. Two alternatives were developed for LUC change and threats to urban wetland sustainability: a zero alternative that simulated trends in urban development and wetland conservation under a business as usual scenario, in the absence of prescribed planning and zoning actions; and an alternative focused on implementation of current urban development plans, which simulated future LUC to account for prescribed wetland conservation strategies. Results show no improvement in future wetland conditions under Saskatoon’s planned growth and wetland conservation scenario versus the business as usual scenario. Results also indicate that a blanket wetland conservation strategy for the city may not be sufficient to overcome the historic trend of urban wetland loss; and that spatially distributed conservation rates, based on individual wetland water catchment LUC differences, may be more effective in terms of wetland conservation. The results also demonstrate the challenges to applied SEA in a rapidly changing urban context, where data are often sparse and inconsistent across the urban region, and provides potential solutions through LUC classification and prediction tools to help overcome data limitations to support land use planning decisions for wetland conservation. The third manuscript presents an analytical approach to SEA, bridging strategic level assessment with operational planning and implementation. An expert-based strategic assessment framework was developed and applied to assess the potential implications of alternative wetland conservation policy targets on urban planning goals, and to identify a preferred conservation policy target. Site-specific algorithms, based on wetland area and wetland sustainability, were used to prioritize wetlands for conservation to meet policy targets within urban planning units. Results indicate a preferred wetland conservation policy target beyond which higher targets provided no additional benefit to urban development goals. The use of different implementation strategies, based on wetland area versus wetland sustainability, provides operational guidance and choice for planners to meet policy objectives within neighborhood planning units, but those choices have implications for local land use and wetland sustainability. Overall, the research contributes to the following aspects of SEA design and methodology: i) scoping processes to define the spatial and temporal context for SEA; ii) baseline assessment for analysis of environmental conditions and changes across space and/or over time; iii) methods to support the identification and evaluation of potential impacts of strategic alternatives; and iv) structured and systematic, quantitative assessment and decision-support tools for SEA that bridge strategic-level assessment with operational planning and implementation.
632

An assessment of the adequacy of the present legal regime for the conservation of wetlands and estuaries in South Africa

Booys, Ernest Jacobus January 2011 (has links)
The significance of this research is to see if South Africa needs wetland and estuarine specific legislation to conserve these ecosystems. Indeed, South Africa is in need of wetland and estuarine specific legislat ion, to conserve wetlands and estuaries for future generations to come. The current law and policies do not suffice to conserve these service systems. South Africa does have statutes which afford protection to these ecosystems, but this protection is limited with regard to wetlands and estuaries. / Magister Legum - LLM
633

Temporal effect on nitrogen removal in a subsurface flow constructed wetland

Hanson, Carter Curtis January 1996 (has links)
A subsurface flow constructed wetland planted with the common reed (Phragmites australis) and softstem bulrush (Scirpus validus) was built in East Central Indiana. The objective of this study was to determine if temperature had an effect on nitrogen (N) removal from the wetland. The research was conducted from the first week of October 3, 1995 to the first week in December 5, 1995 why the wetland froze. Water samples were taken from 5 samplings sites in the system. Each sample was analyzed for organic-N, ammonia, nitrate, and total-N. In the system statistically significant amounts of organic-N, nitrate, and total-N were removed. Ammonia lever reductions, however, were not significant. Organic-N had a mean removal of 37% (8 mg/1) 'Nitrate had a mean removal of 96% (2.3 mg/1). Total-N removal over the sampling period averaged 30% (12 mg/1). The N results were regressed against air and wastewater temperatures. Wastewater temperature was more important because it had a direct impact can the plants and microbes in the system. Warmer temperatures sustained a higher metabolism for the biota in the system. Air temperature had an indirect impact on efficiency of N removal from the wastewater flowing through the wetland. The primary impact .: f the air temperature was on water temperature which then affected the metabolism of or a nc ns in the wetland cell. Greater removal efficiencies were seen during high temperature periods and lower removal efficiencies were noted when the temperatures were low. / Department of Natural Resources and Environmental Management
634

Determining the potential for wetland construction within a linear park setting

Flaugh, Dianne L. January 1991 (has links)
The purpose of this creative project was to outline the concept of Wetland Incentive Zones and to develop a site masterplan based on this concept. Meant as an alternative to large single-site wetland banks, Wetland Incentive Zones would be linear areas of land where wetland construction and preservation efforts would be concentrated. The linear structure would distribute the benefits associated with wetlands through a greater area than would a typical wetland bank. If linked together, the zones would form a network of recreational greenways and function as a travel corridor for wildlife. Participating zone landowners would benefit from tax abatements on wetland acreage and other incentive programs. The public would benefit from the preservation and construction of wetlands and the zone's recreational and educational elements.The masterplan was developed to direct wetland site development opportunities and public recreation and educational functions within a 3200 acre study site located in Allen County, Indiana. This site masterplan identified areas suitable for wetland construction, investigated their potential as wildlife habitat, and the wetland condition likely to be supported. The development plan for the site was focused on the use of an abandoned railroad line as a trail system for public recreation and educational use. / Department of Landscape Architecture
635

Nitrogen removal and biomass production from a harvested and unharvested scirpus wetland

Schultz, Paul Eaton January 1997 (has links)
A subsurface flow constructed wetland was built at the Wastewater Treatment Plant in Muncie, Indiana, in May, 1995. In May, 1996, this wetland was divided into two equal cells and planted with Scirpus validus vahl (softstem bulrush). Samples were collected from July 30, 1996, through October 22, 1996. This study had two objectives. The first was to determine if harvesting the aboveground biomass of the Scirpus would affect the wetland's ability to remove nitrogen from the wastewater. The second objective of this study was to determine if harvesting the bulrush twice during a growing season would substantially increase the annual biomass production. Water was collected from four locations in each cell and analyzed for organic nitrogen, ammonical nitrogen, nitrate, and total nitrogen. The concentration of each nitrogen parameter was significantly reduced between the inlet and well 1 in each cell of the wetland. There were no significant reductions in nitrogen concentration in subsequent sampling locations. There were also no significant differences between the two wetland cells. / Department of Natural Resources and Environmental Management
636

Relationship between 20th century dune migration and wetland formation at Cape Cod National Seashore, Massachusetts / Relationship between twentieth century dune migration and wetland formation at Cape Cod National Seashore, Massachusetts

Sagintayev, Zhanay January 2006 (has links)
Outer Cape Cod (Massachusetts) is dominated by active and stabilizing parabolic and transverse dunes interspersed with numerous inter-dune wetlands. Dune migration has been significantly affected by human activities; conversely, current dune movements are affecting local populations. The objective of the reported research was to assess, using remote sensing and geographic information systems (GIS) technologies, migration of the Cape Cod dunes and the effect of dune movement on distribution of associated wetlands. Aerial photographs from 1938 through 2003 were analyzed to track individual dune movements and subsequent wetland propagation and expansion. Absolute dune movement rates during this period were computed, with a plot of dune movement as a cumulative function. One sub-problem of this study was to quantify `white' areas of active moving sand and `dark' areas of vegetation, in order to quantify changes in vegetative cover with wetland propagation and, conversely, vegetative disappearance with dune movement. Attempts were made to correlate the Palmer Drought Severity Index (PDSI) with dune migration. Based on review of aerial photographs, parabolic dunes have migrated 150 to 250 m since 1938, with 60% of the movement occurring between 1938 and 1977. The relation between absolute parabolic dune migration and corresponding PDSI is approximately logarithmic. Maximum dune migration is associated with PDSI values lower than -2 and reflects moderate drought conditions. Wetlands consistently trailed the dunes, and the distance of wetland movement was related to dune movement distances. Wetland migration was particularly marked from the 1950s to the 1980s. Based on review of georeferenced aerial photographs, it is concluded that marked stabilization of Cape Cod dunes occurred in the 1980s and 1990s, with renewed movement in the 21st Century. This study provides a practical application for assessment of dune migration and vegetative transformations over time using remote sensing and GIS technologies. / Department of Natural Resources and Environmental Management
637

Evaluating the effectiveness of commercial nitrifying bacteria in a constructed wetland

Smith, Timothy R. January 1996 (has links)
This research was conducted to determine the effects of commercially available nitrifying bacteria in a constructed wetland. The study was conducted at Paws, Inc., near Desoto, Indiana during the summer of 1995. The wetland, called Solar Aquatics Treatment System (SAS), was developed by Ecological Engineering Associates and constructed in a, greenhouse. The commercial nitrifying bacteria (Bacta-Pur), contained Nitrosomonas and Nitrobacter Spp. and have been added to the wetland for the past five years to aid in the removal of nitrogen.Water samples were taken from the wetland and analyzed for ammonia, nitrite, nitrate, dissolved oxygen, hydrogen ion concentrations and water temperature from Monday through Friday for three weeks. A baseline was established from these samples. After three weeks of testing the addition of Bacta-Pur to the wetland was discontinued.To determine whether these additional bacteria were needed, testing without the Bacta-Pur was conducted for three weeks. These samples were collected and analyzed for the same parameters as those used to establish baseline information.Ammonia concentrations were significantly lower without the addition of Bacta-Pur bacteria. There were no significant differences for concentrations of nitrite and nitrate. The water temperature was higher in the three weeks when no Bacta-Pur was added. This was due to the increase in ambient temperature which caused the water temperature in the SAS to increase. Since the nitrogen compounds either remained the same or decreased in concentration at the effluent without the addition of bacteria, the addition of Bacta-Pur is not needed in order to remain in compliance with EPA regulations for effluent standards.A container experiment was conducted to provide an' environment that had no introduced bacteria before the addition of Bacta-Pur. There were no significant differences for the nitrogen compounds between wastewater samples with addition and without addition of Bacta-Pur bacteria. / Department of Natural Resources and Environmental Management
638

A watershed approach to decrease flooding of Pipe creek in Alexandria, Indiana

Zapf, Jeff January 1996 (has links)
This project explores one method of controlling flooding of Pipe Creek in Alexandria, Indiana. The method used is one of placing wetlands and grass filters within one subwatershed of Pipe Creek to reduce peak discharge and the time to peak discharge. A computer program called Sedimot II was used to determine the peak discharge for the Thurston Ditch subwatershed of Pipe Creek. Both 10 and 50 year 24 hour storms were studied. Following the construction of base line hydrographs for both storm events, four examples of wetland and grass filter placement were shown for the watershed. Hydrographs were then produced for all four alternatives for both 10 and 50 year storms. Recommendations were then made on how these examples could be used in the rest of the Pipe Creek watershed to further reduce the potential for flooding in Alexandria. / Department of Landscape Architecture
639

The efficiency of constructed wetlands for the removal of the antimicrobial agent triclosan from wastewater

Zinn, Elizabeth R. 15 December 2012 (has links)
Access to abstract restricted until December 2014. / Review of relevant literature -- Efficiency of constructed wetlands to remove an antimicrobial agent triclosan from wastewater -- The removal of triclosan from laboratory scale constructed wetlands with four species of wetland plants -- Additional research : determination of the hydraulic retention time in an operational subsurface constructed wetland -- Additional research methods : the evaluation of the subsurface constructed wetland for the treatment of iron, phosphorus, ammonia, nitrite, nitrate, dissolved oxygen, pH and E. coli. / Access to thesis restricted until December 2014 / Department of Natural Resources and Environmental Management
640

A system for supporting wetland management decisions.

Kotze, Donovan Charles. 19 December 2013 (has links)
In South Africa, the loss of wetlands and their associated benefits has been considerable. A need was identified for a system that, using available information, would assist in achieving a balance between local, mainly short-term benefits to individuals and spatially wider and longer term benefits to society. Such a system, termed WETLAND-USE, was developed with the philosophy that:(l) wetlands have been well demonstrated to supply several indirect benefits to society (e.g. water quality enhancement); (2) the impact on these benefits can be described on a qualitative basis using field indicators that characterize the wetland and the disturbance associated with a particular land-use; (3) this information can be communicated to wetland users, which will contribute to achieving a desired balance, provided there is an enabling organizational environment and due consideration is taken of the socio-economic and organizational factors affecting wetland management. The primary conceptual framework underlying WETLAND-USE was the pressure-state-perceptions-policy framework, which depicts: the mode of use (i.e. the pressure); how this affects the state of the system (including its underlying processes and the goods and services it delivers); which in turn shape the perceptions that ultimately determine the policy pertaining to further use. This cycle is repeated at a range of organizational levels from local to national and takes place within a particular socioeconomic context. WETLAND-USE, which was designed for use by fieldworkers, and built using a rule-based, expert system approach, has two main parts, dealing largely with biophysical and social aspects respectively. Part 1, which guides the collection of data relating to the state of the wetland, assists in: (1) predicting the likely impacts of disturbances associated with a proposed land-use (the pressure) on the wetland state, and (2) providing ongoing management guidelines for particular land-uses. Part 2 assists in: (1) describing the social, land tenure and policy contexts of the wetland; and (2) establishing and maintaining organizational arrangements, local policy and management objectives and goals. Several discrete investigations were required for the development and refinement of WETLAND-USE, which was done in an iterative fashion. Initial discrete investigations fed into the development of a prototype system which was refined through evaluation using a questionnaire survey and further discrete investigations. The revised system was re-evaluated using a fieldworkshop approach and, based on the performance of the system in the field, it was revised further to produce the final system. In the two initial discrete studies, protocols were developed for characterizing key physical determinants of wetland functioning, notably: (1) degree of wetness, one of the primary functional determinants, described in the field using readily identifiable soil morphological indicators (e.g. matrix chroma and mottles) and (2) landform setting, which strongly influences local flow patterns and lateral exchange of water and water-borne materials. Graminoid plant species composition and functional groups (defined in terms of photosynthetic pathway) were then described in relation to the above physical determinants, together with rainfall, temperature and soil texture, within wetlands spanning a wide altitudinal range. This revealed that degree of wetness and altitude had the strongest influence over the vegetation parameters examined. An investigation into incorporating cumulative impacts into wetland decision making revealed that consideration should be given to: wetland loss in relation to ecoregions and catchments, and the relation of change in wetland extent, spatial configuration and context respectively to wetland function. Current conservation initiatives in KwaZulu-Natal were shown to account poorly for cumulative impacts on wetlands. Rules of thumb for making such considerations, given severe data limitations, were developed with reference to the high turn-over of species along the altitudinal gradient observed in the vegetation study. The "rules" were than applied to a case-study, the upper Mgeni catchment, as part of an initiative to engage a diversity of stakeholders in wetland information gathering and use. This resulted in the selection of priority wetlands in the catchment and an examination of the extent to which integration had been achieved vertically (across hierarchical levels) and horizontally (across organizations within particular hierarchical levels). In order to broaden the range of land-uses accounted for by the WETLAND-USE prototype, it was applied to a communally used wetland, Mbongolwane, and found to account poorly for the traditional cultivation and vegetation harvesting practices encountered. WETLAND-USE was modified to include a greater diversity of land-use types as well as enhancing its capacity to allow assessments to be conducted using the system's general criteria, thereby making WETLAND-USE more robust. In enhancing the capacity of WETLAND-USE to account for the social and organizational dimension of wetland management, the involvement of local and outside organizations in influencing wetland resource use in five sites was examined in relation to predefined frameworks. The sites, Mandlazini wetland, Mbongolwane wetland, Blood River vlei, Ntabamhlope vlei and Wakkerstroom vlei were chosen to represent a diversity of social contexts and management authorities. This revealed that in communally used areas in particular, a wide range of organizations are involved to varying degrees in influencing the use of different wetland resources. The level to which the local organizational environment contributed to sustainable use varied greatly among wetlands, but in all cases had important deficiencies: (1) self-governing resource-management organizations were largely lacking and in communal areas were weakening under contemporary conditions; and (2) although a formal management system was in place in two of the five wetlands, it was largely absent in the remaining three. There has been little involvement from extension services in facilitating local policy development and in promoting alternative land-uses which have less pressure on the state of the wetland. Local wetland management policy and collaboration among land-owners in wetlands under multiple separate ownership such as Blood River vlei was identified as being particularly poor. The evaluations of WETLAND-USE revealed that, in relation to the underlying philosophy of the thesis, WETLAND-USE had been improved through field application and incorporation of the findings of the discrete investigations. Nevertheless, important limitations of the study were highlighted, including: its high level of reliance on expert opinion in the face of a paucity of empirical data relating to the functioning of local wetlands and their attendant benefits (and how these are affected by anthropogenic disturbances), and a particularly shallow representation of socio-economic factors. The identification of these limitations was useful in highlighting key areas for further research. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1999.

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