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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

Effects of land cover and climate changes on runoff and sediment yield from a forested catchment in northern Iran

Hajian, Farhad January 2013 (has links)
There have been more than 3700 recorded floods in Iran during the 50 years to around 2005, of which slightly more than half occurred during the final decade of this period. Over a longer period (1909-2004), floods in Iran caused economic losses in excess of US$3.5 billion. These floods, and associated erosion problems, have previously been attributed to land cover change and climate change. This research aimed to investigate future runoff changes in a small forested catchment in northern Iran for which appropriate and sufficient data exist to support such analyses. Approaches for estimating erosion and sediment production from the same catchment in the absence of relevant detailed data were also examined. The selected study site was the Casilian Catchment, with the town of Sangdeh at its centre. This is an elongated catchment approximately 17.8 km long with a mean catchment slope of 34.3% or 18.8°. The upstream half of the catchment is forested and, as such, could theoretically be susceptible to significant deforestation in the future. As such, it provides a suitable basis for the examination of hydrological implications – particularly runoff change – resulting from significant land cover change. To investigate the land cover change impact on runoff (volume and peak discharge of the outflow from the catchment), the approach used in this study was to use the Soil Conservation Service (SCS) curve number method with spatial catchment data using a Geographical Information System (GIS) and the SCS dimensionless unit hydrograph. The effects of rainfall characteristics and antecedent soil water content on runoff were also investigated. Runoff changes between observed period (1980-1986) and three different future periods (2011-2017, 2046-2052 and 2080-2086), for the Casilian Catchment, were estimated using the Hydrologic Engineering Centre-Hydrologic Modelling Systems (HEC-HMS) rainfall-runoff model. Thirteen climate models provided the required input variables (temperature, rainfall) to the rainfall-runoff model, under three different scenarios (A2, B1, and A1B) using the the ‘Long Ashton Research Station’ weather generator known as LARS-WG. This was used to downscale the Global Climate Model (GCM) to the Sangdeh Station to overcome the limitations of the coarse scale GCM output. Temperature was used to calculate potential evapotranspiration required for HMS rainfall-runoff model. The two empirical erosion models, known as the Erosion Potential Method (EPM) and Pacific South-West Inter-Agency Committee (PSIAC) methods, were evaluated to estimate sediment yield for the Casilian Catchment. Further, areas with high erosion intensity were identified, and factors affecting erosion were determined for the Casilian Catchment. In the EPM method, only three processes are used to prepare an erosion intensity map, but nine processes are considered in the PSIAC method. Runoff volume and the peak flow are considered to estimate erosion intensity and sediment yield in the PSIAC method, but not in the EPM method. Soil characteristics are also considered in erosion intensity and sediment yield estimation in the PSIAC method but not in the EPM method. The calculated mean annual specific sediment yield of the Casilian Catchment using the PSIAC method (482 t km-2yr-1) was closer to a measured value for the Talar Catchment (532 t km-2 y-1), of which Casilian is a subcatchment. Thus, the PSIAC-based erosion intensity map seems to be more representative of the erosion condition of the the Casilian Catchment. Slope, magnitude and intensity of rainfall, soil and land cover can be important factors affecting soil erosion of the Casilian Catchment. From this research, it was found that antecedent soil water content, magnitude and intensity of rainfall and the area affected by land cover change relative to the catchment size are important factors affecting runoff characteristics (volume of runoff and peak discharge). In the future, the mean rainfall totals (especially mean annual rainfall) and frequency of extreme rainfall events and rainfall intensity may increase due to an increase in atmospheric water vapour for the Casilian Catchment and probably other small catchments in northern Iran. Therefore, these catchments may be subjected to more flooding and erosion in the future as a result of changes in the rainfall characteristics. The findings of this research show that land cover change (e.g. deforestation and agricultural activities) should be given more consideration in the management of small catchments in northern Iran in the future, due to the consequences of climate change.
62

The potential and prospects for enabling small area geodemographics and geomarketing in developing countries : a case study on Nigeria

Allo, Nicholas Babatope January 2012 (has links)
Identifying what can be considered as 'prospects and potentials' for small-area geodemographics and also geomarketing in a developing country like Nigeria, prompts the need to raise several deep searching questions, many of which this study attempts to answer as best possible. Also, the study of geodemography and geomarketing, its approaches and procedures in Britain, when contrasted against what exists in Nigeria reveals: coarse spatial resolutions for data, societal or self imposed restrictions with regards data access and also a Jacking or an inaccurate collection of spatial geographies (digital boundaries) and population information, all of which makes geodemography and geomarketing near impossible in a country like Nigeria. Responding to questions from within this study, attention is directed towards the derivation of geographic and topographic features extracted from satellite imagery as an easily accessible source for data. In addition, focus is drawn to the approach of dasymetric mapping, which is adopted as a means for interpolating population counts from Nigeria's 2006 census geography into derived small-area geographies created and used by this study - Small Basic Spatial Units (SBSU). Furthermore, output from questionnaires distributed within the research Area of Interest (ADI) is used in validating lifestyle characteristics attributed from within this study and extrapolated from Nigeria's 2006 census domains. This is done in conjunction with an approach adapted from architectural space planning for use in estimating the number of persons and households, present or living within each property outline derived, after which a classification is undertaken using the derived SBSU. The final output, after all geoprocessing r is a ten cluster geodemographic profile. This derived geodemographic profile, when used to examine a financial institution - FirstBank Nigeria PLC - and its services within the research ADI, presents what is understood to represent a pen portrait of the provider's customer distribution, potentially able to impact positively FirstBank's strategy of product and service delivery, preferred channels for customer access and consumption patterns, showing anticipated spending habits, lifestyles and also, offers a socio-economic placement for ACI resident population. Availability of such information will enable the service provider to identify products and services from its portfolio that are better suited to customers within the ACI, rather than offer 'one size fits all services', as is believed to often happen in developing countries.
63

Violence against women of Pakistan : a case study of the Cholistan desert

Aziz, Samehia January 2012 (has links)
Women continue to be subjected to violations of their human rights. Violence towards them is a crucial mechanism through which women are subjugated. Gender based violence is a silent global epidemic (UNDP 2011) and its devastating effects cannot be underestimated. This thesis proposes an integrated geographical or place-based approach to understand gender based violence. It offers an enhanced, theoretically more rigorous, 'spatialised' ecological model. The traditional ecological model has been reworked as a multi-dimensional structure, where the layers are (re)conceptualised as simultaneously social and spatial units constructed through and constituted in their connectedness with each other and with elsewhere; with spaces within, through and beyond them. In the new model, the layers are portrayed not as separate from one another, but rather linked together in a single interconnected whole. The ways in which risk factors interconnect with each other and mesh together fashion 'spaces of vulnerability' where violence against women is normalized and legitimated. Cholistan is one such place; a place of intense vulnerability. The 'roots' of gender based violence in Cholistan are deep and entrenched; interconnecting in complex ways to bestow adangerous and devastating legacy on Cholistani women. The thesis adopts a mixed method approach. In total 900 cases of abuse were examined. In addition, 17 interviews were conducted with a variety of key gatekeepers and 25 victim women were interviewed. In total 10 local community leaders were also interviewed in a group forum. The thesis presents evidence of the widespread and persistent abuse of Cholistani women. Violence towards women in Cholistan takes a myriad of forms. some of which are universal, some of which are culturally specific, embedded in the socio-cultural norms and traditions found in this isolated, barren and geographically remote locale. These include factors such as the propensity of exchange marriages, extended family structures, childlessness, son preference, as well as dowry-related issues and poverty; compounded by a lack of functioning state-led judiciary or law enforcement agencies; leaving no avenue of recourse for women These factors interrelate with each other in complex ways and at a variety of scales; to creating a space in Cholistan where violence against women is legitimated, sanctioned and ultimately played out.
64

An evaluation of downland turf re-creation, using invertebrates as indicators

Hoare, Annabel January 1999 (has links)
Seven study sites within the South Wessex Downs Environmentally Sensitive Area (SWD ESA) were used to evaluate re-created downland turf, a habitat created under one of the scheme management options. The novel habitat was compared to adjacent areas of established downland and to the edges of arable fields, by collecting vegetation data, and using invertebrates as indicators of habitat quality. The recreated downland sites were re-seeded 1 to 3 years before the study. The new habitat was influenced by adjacent established downland and calcicolous species were found colonising the: edges of the re-created downland. The edges of established downland were degraded in terms of plant species richness, probably by previous arable use in adjacent fields. It was found that the re-created downland was being used by several butterfly species for breeding as well as for nectaring and that these activities were concentrated around the edges of the habitat. A second indicator group, the Homoptera, were also found on the re-created downland and, although no evidence of breeding was gathered, some of the species found on the habitat were characteristic of established downland. A third aspect of the study focused on the effect on associated herbivores of the nonnative varieties of downland species which are sown into the re-created downland. It was found that these were not as easily digested as a native variety and that although the larvae gained more weight they pupated later, thus increasing their chances of predation. This has not previously been demonstrated and it is hoped that they will help improve the management of the SWD ESA in future years.
65

An investigation into the importance of propagule provenance in restoration ecology

Smith, Barbara Maria January 2002 (has links)
There is increasing concern among restoration ecologists that using non-local propagules in revegetation schemes may influence the success of grassland restoration. This research programme investigated the importance of propagule provenance in restoration schemes. In particular the work focused on two areas. Firstly, the study investigated the significance of propagule provenance for plant establishment and persistence using Lotus corniculatus as a model species. Secondly, it investigated the practical implications of restricting seed procurement to local sources, using a field trial which assessed the success of limestone grassland re-creation under different treatments. Propagules were collected from two contrasting habitats within each of six regions in the British Isles and a common garden experiment was used to quantify the genetic component of provenance as estimated by plant morphology and fitness. There were differences in survival, growth habit, pubescence, leaf shape, plant size and fecundity between plants grown from seeds sourced from different regions. In addition these populations differed in the extent to which they were damaged by seed herbivores. Differences between plants grown from seed sourced from contrasting habitats were limited to morphology. These findings suggested that populations would be likely to perform differentially in a restoration environment. Both geographical location and the ecological conditions at the seed source should be considered when procuring seeds for a restoration scheme. A field trial was set up to establish whether local propagules exhibited higher fitness than those collected from non-local sources. Propagules were collected from two contrasting habitats in each of fifteen regions. Two restoration environments at a single site were investigated; one was treated with a dressing of topsoil, the other site was untreated bare clay substrate. Differences between populations were measured in terms of both geographical and ecological distance. Results for both sites demonstrated that although there was no home-site advantage in terms of geographical distance, plants from more distant populations were smaller and less fecund in the restoration environment. An investigation into the relationship between ecological distance and plant performance produced different results on the treated and untreated plots. On the treated plot there was no significant relationship but on the untreated plot, plants from more distant populations were larger and more fecund. The contrast in the results obtained for the effect of geographical and ecological distance on performance in the untreated restoration environment is interesting. The enhanced performance of geographically local populations agrees with findings from previous studies. The findings for ecological distance are unexpected based on other work. However, it is postulated that the initial success of non-local populations maybe misleading, as environmental conditions which are infrequent but typical of the area may lead to high mortalities in the longterm. The range of what can be considered local is rarely considered in studies that investigate plant provenance, but work from other areas suggests that there is sufficient variation over small distances to warrant seed collection within 100m. Fine scale phenotypic variation over 200m in populations of L. corniculatus was investigated, however there was no evidence to suggest that seed collection should be restricted to 100m, consequently seeds could be safely collected up to 200m from a restoration site. If seed procurement is to be restricted to local seed then it is possible that the seed application rate and species mix available for a restoration project may be limited. A field trial investigating the effect of different treatments showed that it is possible to establish an appropriate plant community using a low sowing rate. However, that community will be more vulnerable to changes in the environment during the establishment phase and more open to invasion by colonizing species which are likely to be weedy in the first few years. A comparison of two seed mixes showed that a diverse seed mix resulted in an increased diversity and evenness of vegetation. There was no benefit in adding a nurse grass to compensate for a low application rate of local species. In conclusion, although it is an advantage to use seeds of local provenance in restoration schemes, it will be necessary to balance this with the likelihood of successful re-vegetation given the seed available
66

Automated interpretation of digital images of hydrographic charts

Goodson, Kelvin J. January 1987 (has links)
Details of research into the automated generation of a digital database of hydrographic charts is presented. Low level processing of digital images of hydrographic charts provides image line feature segments which serve as input to a semi-automated feature extraction system, (SAFE). This system is able to perform a great deal of the building of chart features from the image segments simply on the basis of proximity of the segments. The system solicits user interaction when ambiguities arise. IThe creation of an intelligent knowledge based system (IKBS) implemented in the form of a backward chained production rule based system, which cooperates with the SAFE system, is described. The 1KBS attempts to resolve ambiguities using domain knowledge coded in the form of production rules. The two systems communicate by the passing of goals from SAFE to the IKBS and the return of a certainty factor by the IKBS for each goal submitted. The SAFE system can make additional feature building decisions on the basis of collected sets of certainty factors, thus reducing the need for user interaction. This thesis establishes that the cooperating IKBS approach to image interpretation offers an effective route to automated image understanding.
67

Conserving inter-tidal wetlands : a regional ecosystem-based approach to rehabilitation and recreation

Johnson, David Edward January 1998 (has links)
Integrated Coastal Zone Management (ICZM) depends on the recognition that benefits associated with healthy functioning (function benefits) of ecosystems are irreplaceable in ecological, geomorphological and social terms. A methodology for evaluating different inter-tidal wetlands on the basis of indicators representing their full range of functions is presented. Each inter-tidal wetland is attributed a function related score. These scores are region specific. Whilst they allow a ranking of inter-tidal wetland importance, they do not equate to economic value. A key advantage of this approach is that it quantifies the regional resource, and forms a basis upon which to consider the impact of future pressures and prioritise conservation actions. The methodology has been applied to the Solent and Poole Bay Marine Natural Area (MNA). The 13 inter-tidal wetlands within this region have been scored and ranked, highlighting the relative importance of the large inter-tidal wetlands of Poole, chichester and Langstone Harbours compared with the snmaller inter-tidal wetlands of the north shore of the Isle of Wight. The main challenges facing the conservation of this regional resource are evaluated and the cumulative impact/risk of key pressures is assessed. Lymington/Keyhaven and Southampton Water are considered to be the regional inter-tidal wetlands whose function benefits are most at risk over the next 20 years. A restoration target of 1200 ha of inter-tidal wetland is suggested for the MNA, with a recommendation that re-creation efforts should focus on Chichester Harbour. A detailed case study of the Lymington/Keyhaven inter-tidal wetland is presented. Technical rehabilitation solutions are suggested based on the synthesis of physical and ecological survey date. This research concludes that work to restore inter-tidal wetlands is urgently needed. Such work requires appropriate central Government funding together with a new mechanism, over and above existing compulstory purchase powers, to rationalize coastal landholdings. Investment should concentrate initially on the most easily rehabilitated and re-created sites, to offset the impact of natural forcing mechanisms associated with global environmental change. A role for environmental mediators in identified to raise the political and social acceptability of inter-tidal wetland restoration and a regional ecosystem-based approach is suggested as the best way forward
68

Sustainabilty systems appraisal for integrated coastal zone management

Gallagher, Anthony W. January 2006 (has links)
Integrated Coastal Zone Management (ICZM) is a process defined in terms of achieving sustainable development. Despite sustainability being accepted by the majority of organizations currently operating on the coast, the integrated approach is seen as the more constructive and benificial alternative to achieve this state. Id 'success' for ICZM means sustainable development, then the question is raised as to how it attempts to achieve this, and, more speficically, how effectively it does so? Put another way, how can the management process be evaluated in terms of achieving its aims? Despite sevaral attempts to produce sustainability indicator sets, there is currently no established or validated way of assessing the effectiveness of ICZM initiatives and consequently there is also no national overview with thish to judge the strategic performance of coastal partnerships (CPs). This study aims to address this failing by developing and critically evaluating a standardised operating mechanism for assessing the ability of ICZM initiatives to achieve sustainable development. In order to develop this 'Coastal Sustainability Standard', a review was made of the current role and treatment of sustainability in coastal planning and management in the UK. Using the electronic database of the company 'Coastal Management for Sustainability' (CMS), a survey of UK coastal practitioners was carried out as to the key theoretical constructs inherent in the concept of sustainability. Textual analysis of the results, using the qualitative software package, Nud*ist 6, revealed six dominant constructs which would form the basis for the development of the standard. These six - planning; participation; communication; integration; responsibility and balance were defined as principles, and a set of criteria developed for each, with which to enable assessment. A scoring system and a set of guidelines were then designed to maximise the level of objectivity in carrying out the assessment, with the scoring system also reflecting the systems thinking inherent in the design. In order to validate the mechanism, three case study CPs were selected against which to carry out a detailed application of the Standard. These were the Exe Estuary Management Partnership (EEMP); Tamar Estuaries Consultative Forum (TECF) and Pembrokeshire Coastal Forum (PCF), all of which scored relatively poorly. That none of the three CPs achieved the pre-requisite standard raised a number of considerations relating to the efficacy of the Standard and its operation, as well as to the nature of ICZM in the UK and its aim of achieving sustainable development. Conclusions drawn from this evaluation identified that the current operation of ICZM in the UK exhibits a disjointed approach to achieving its long-term goals, as a result of its voluntary nature. The voluntary approach employed in the UK can be seen to be at the root of a number of problems facing the successful development of ICZM. In terms of resources, it has implications for the skills, knowledge and training of coastal managers, as well as the funding available to develop and implement effective plans. The voluntary approach also does not necessarily 'encourage' appropriate cultural changes within or between stakeholder organizations, and does not impart joint responsibility or collective liability upon stakeholders to achieve sustainable development.
69

Stakeholder involvement in coastal partnerships in the UK : towards secure representation

Fletcher, Stephen January 2003 (has links)
Coastal Partnerships (CPs) have emerged since the early 1990s as a local and regional response to the national coastal management policy vacuum in the United Kingdom (UK). CPs are voluntary groupings of stakeholders aspiring to improved coastal resource use through integrated coastal management (ICM). CPs use the rationale of deliberative consensus building to develop and implement multi-sectoral coastal management strategies to deliver ICM. Despite the significance of CPs, there has been a lack of research into their effectiveness in securing meaningful representation of stakeholder views in decision-making. Poor stakeholder representation has the potential to undermine the credibility, legitimacy, accountability and democratic basis of CP management outputs. Through a telephone interview schedule with CP officers in the UK, the procedures and safeguards in place to accommodate stakeholder representation were evaluated. Results indicated that CPs have restrictive and variable membership criteria and unclear decision making procedures. These limitations exposed CPs to poor inclusivity and served to maintain existing power relations amongs stakeholders. It was also apparent that CPs had little information concerning the legitimacy of those representing stakeholder constituencies, potentially risking exposure to misrepresentattion. In order to examine these issues further, four case study CPs were selected and a personal interview schedule undertaken with stakeholder representatives. It was found that representatives were, in general the legitimate representative of their constituency, that most held a trustee relationship with their constituency, but generally had limited accountability - both individually and collectively. Representatives perceived the decision-making process of CPs to favour already powerful groups, which served to limit the credibility of the CP amongst the membership. The concept of secure representation was developed to describe circumstances in which stakeholder representation could be assured. It was determined that secure representation occurred when representatives were responsive to their constituency, when CPs had an inclusive membership and when decision-making was fair to all involved. Specific internal and external management measures to deliver secure representation were defined. This facilitated the development of a conceptual model that mapped secure representation against specific management measures. The model allowed particular routes to be identified for CPs to enhance their secure representation. It was concluded that both the procedures and safeguards within CPs and the management measures within stakeholder constituencies required reform. Central to this reform was the need for CPs to extend their sphere of influence to enhance the representation of stakeholder constituencies within coastal decision-making
70

NM2002 impact assessment : impact assessment report

Lochner, Paul January 1992 (has links)
Bibliography: p. 94-95. / The purpose of this report is to: * assess the biophysical and socio-economic impacts of closure of De Beers Namaqualand Mines (DBNM) * provide preliminary suggestions for mitigation measures. DBNM anticipate that they will close in approximately 10 years' time. By the year 2002, all diamond deposits which are currently economically viable to mine on a large-scale would have been exploited. Closure is anticipated to have a significant impact on DBNM employees, their households, and towns where the households of employees live. Furthermore, closure is anticipated to have a significant impact on the Namaqualand economy. Therefore, DBNM commissioned the EEU to undertake an assessment of the impacts resulting from mine closure, to ascertain the effects on their employers and their affected households and communities. Through discussions with DBNM the scope for this assessment was established: * Briefly to describe the current biophysical, social and economic environments in Namaqualand and identify different trends in the region. * To assess in detail the socio-economic impacts resulting from the closure of DBNM. In addition, this report considers the impacts on the biophysical environment resulting from the closure of DBNM, because the socio-economic well-being of employees from rural areas of Namaqualand and Transkei is intrinsically linked to changes in the biophysical environment. Lastly, this report also contains preliminary suggestions for mitigating the impacts of closure.

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