A suitability study for the implementation of a corporate geographic information system at the King Sabata Dalindyebo Municipality
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
A multiscale remote sensing assessment of subtropical indigenous forests along the wild coast, South Africa
- Authors: Blessing, Sithole Vhusomuzi
- Date: 2015
- Subjects: Forests and forestry -- South Africa -- Remote sensing , Forest conservation , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10677 , http://hdl.handle.net/10948/d1021169
- Description: The subtropical forests located along South Africa’s Wild Coast region, declared as one of the biodiversity hotspots, provide benefits to the local and national economy. However, there is evidence of increased pressure exerted on the forests by growing population and reduced income from activities not related to forest products. The ability of remote sensing to quantify subtropical forest changes over time, perform species discrimination (using field spectroscopy) and integrating field spectral and multispectral data were all assessed in this study. Investigations were conducted at pixel, leaf and sub-pixel levels. Both per-pixel and sub-pixel classification methods were used for improved forest characterisation. Using SPOT 6 imagery for 2013, the study determined the best classification algorithm for mapping sub-tropical forest and other land cover types to be the maximum likelihood classifier. Maximum likelihood outperformed minimum distance, spectral angle mapper and spectral information divergence algorithms, based on overall accuracy and Kappa coefficient values. Forest change analysis was made based on spectral measurements made at top of the atmosphere (TOC) level. When applied to the 2005 and 2009 SPOT 5 images, subtropical forest changes between 2005-2009 and 2009-2013 were quantified. A temporal analysis of forest cover trends in the periods 2005-2009 and 2009-2013 identified a decreasing trend of -3648.42 and -946.98 ha respectively, which translated to 7.81 percent and 2.20 percent decrease. Although there is evidence of a trend towards decreased rates of forest loss, more conservation efforts are required to protect the Wild Coast ecosystem. Using field spectral measurements data, the hierarchical method (comprising One-way ANOVA with Bonferroni correction, Classification and Regression Trees (CART) and Jeffries Matusita method) successfully selected optimal wavelengths for species discrimination at leaf level. Only 17 out of 2150 wavelengths were identified, thereby reducing the complexities related to data dimensionality. The optimal 17 wavelength bands were noted in the visible (438, 442, 512 and 695 nm), near infrared (724, 729, 750, 758, 856, 936, 1179, 1507 and 1673 nm) and mid-infrared (2220, 2465, 2469 and 2482 nm) portions of the electromagnetic spectrum. The Jeffries-Matusita (JM) distance method confirmed the separability of the selected wavelength bands. Using these 17 wavelengths, linear discriminant analysis (LDA) classified subtropical species at leaf level more accurately than partial least squares discriminant analysis (PLSDA) and random forest (RF). In addition, the study integrated field-collected canopy spectral and multispectral data to discriminate proportions of semi-deciduous and evergreen subtropical forests at sub-pixel level. By using the 2013 land cover (using MLC) to mask non-forested portions before sub-pixel classification (using MTMF), the proportional maps were a product of two classifiers. The proportional maps show higher proportions of evergreen forests along the coast while semi-deciduous subtropical forest species were mainly on inland parts of the Wild Coast. These maps had high accuracy, thereby proving the ability of an integration of field spectral and multispectral data in mapping semi-deciduous and evergreen forest species. Overall, the study has demonstrated the importance of the MLC and LDA and served to integrate field spectral and multispectral data in subtropical forest characterisation at both leaf and top-of-atmosphere levels. The success of both the MLC and LDA further highlighted how essential parametric classifiers are in remote sensing forestry applications. Main subtropical characteristics highlighted in this study were species discrimination at leaf level, quantifying forest change at pixel level and discriminating semi-deciduous and evergreen forests at sub-pixel level.
- Full Text:
- Date Issued: 2015
- Authors: Blessing, Sithole Vhusomuzi
- Date: 2015
- Subjects: Forests and forestry -- South Africa -- Remote sensing , Forest conservation , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10677 , http://hdl.handle.net/10948/d1021169
- Description: The subtropical forests located along South Africa’s Wild Coast region, declared as one of the biodiversity hotspots, provide benefits to the local and national economy. However, there is evidence of increased pressure exerted on the forests by growing population and reduced income from activities not related to forest products. The ability of remote sensing to quantify subtropical forest changes over time, perform species discrimination (using field spectroscopy) and integrating field spectral and multispectral data were all assessed in this study. Investigations were conducted at pixel, leaf and sub-pixel levels. Both per-pixel and sub-pixel classification methods were used for improved forest characterisation. Using SPOT 6 imagery for 2013, the study determined the best classification algorithm for mapping sub-tropical forest and other land cover types to be the maximum likelihood classifier. Maximum likelihood outperformed minimum distance, spectral angle mapper and spectral information divergence algorithms, based on overall accuracy and Kappa coefficient values. Forest change analysis was made based on spectral measurements made at top of the atmosphere (TOC) level. When applied to the 2005 and 2009 SPOT 5 images, subtropical forest changes between 2005-2009 and 2009-2013 were quantified. A temporal analysis of forest cover trends in the periods 2005-2009 and 2009-2013 identified a decreasing trend of -3648.42 and -946.98 ha respectively, which translated to 7.81 percent and 2.20 percent decrease. Although there is evidence of a trend towards decreased rates of forest loss, more conservation efforts are required to protect the Wild Coast ecosystem. Using field spectral measurements data, the hierarchical method (comprising One-way ANOVA with Bonferroni correction, Classification and Regression Trees (CART) and Jeffries Matusita method) successfully selected optimal wavelengths for species discrimination at leaf level. Only 17 out of 2150 wavelengths were identified, thereby reducing the complexities related to data dimensionality. The optimal 17 wavelength bands were noted in the visible (438, 442, 512 and 695 nm), near infrared (724, 729, 750, 758, 856, 936, 1179, 1507 and 1673 nm) and mid-infrared (2220, 2465, 2469 and 2482 nm) portions of the electromagnetic spectrum. The Jeffries-Matusita (JM) distance method confirmed the separability of the selected wavelength bands. Using these 17 wavelengths, linear discriminant analysis (LDA) classified subtropical species at leaf level more accurately than partial least squares discriminant analysis (PLSDA) and random forest (RF). In addition, the study integrated field-collected canopy spectral and multispectral data to discriminate proportions of semi-deciduous and evergreen subtropical forests at sub-pixel level. By using the 2013 land cover (using MLC) to mask non-forested portions before sub-pixel classification (using MTMF), the proportional maps were a product of two classifiers. The proportional maps show higher proportions of evergreen forests along the coast while semi-deciduous subtropical forest species were mainly on inland parts of the Wild Coast. These maps had high accuracy, thereby proving the ability of an integration of field spectral and multispectral data in mapping semi-deciduous and evergreen forest species. Overall, the study has demonstrated the importance of the MLC and LDA and served to integrate field spectral and multispectral data in subtropical forest characterisation at both leaf and top-of-atmosphere levels. The success of both the MLC and LDA further highlighted how essential parametric classifiers are in remote sensing forestry applications. Main subtropical characteristics highlighted in this study were species discrimination at leaf level, quantifying forest change at pixel level and discriminating semi-deciduous and evergreen forests at sub-pixel level.
- Full Text:
- Date Issued: 2015
Properties of traveling ionospheric disturbances (TIDs) over the Western Cape, South Africa
- Authors: Tyalimpi, Vumile Mike
- Date: 2015
- Subjects: Doppler radar , Geographic information systems , Traveling ionospheric disturbances -- south Africa , Ionospheric disturbances -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5557 , http://hdl.handle.net/10962/d1017901
- Description: Travelling Ionospheric Disturbances (TIDs) are said to be produced by atmospheric gravitational waves propagating through the neutral ionosphere. These are smaller in amplitude and period when compared to most ionospheric disturbances and hence more difficult to measure. Very little is known about the properties of the travelling ionospheric disturbances (TIDs) over the Southern Hemisphere regions since studies have been conducted mostly over the Northern Hemisphere regions. This study presents a framework, using a High Frequency (HF) Doppler radar to investigate the physical properties and the possible driving mechanisms of TIDs. This research focuses on studying the characteristics of the TIDs, such as period, velocity and temporal variations, using HF Doppler measurements taken in South Africa. By making use of a Wavelet Analysis technique, the TIDs’ characteristics were determined. A statistical summary on speed and direction of propagation of the observed TIDs was performed. The winter medium scale travelling ionospheric disturbances (MSTIDs) observed are generally faster than the summer MSTIDs. For all seasons, the MSTIDs had a preferred south-southwest direction of propagation. Most of the large scale travelling ionospheric disturbances (LSTIDs) were observed during the night and of these, the spring LSTIDs were fastest when compared to autumn and summer LSTIDs. The general direction of travel of the observed LSTIDs is south-southeast. Total Electron Content (TEC), derived from Global Positioning System (GPS) measurements, were used to validate some of the TID results obtained from the HF Doppler data. The Horizontal Wind Model (HWM07), magnetic K index, and solar terminators were used to determine the possible sources of the observed TIDs. Only 41% of the observed TIDs were successfully linked to their possible sources of excitation. The information gathered from this study will be valuable in future radio communications and will serve as means to improve the existing ionospheric models over the South African region.
- Full Text:
- Date Issued: 2015
- Authors: Tyalimpi, Vumile Mike
- Date: 2015
- Subjects: Doppler radar , Geographic information systems , Traveling ionospheric disturbances -- south Africa , Ionospheric disturbances -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5557 , http://hdl.handle.net/10962/d1017901
- Description: Travelling Ionospheric Disturbances (TIDs) are said to be produced by atmospheric gravitational waves propagating through the neutral ionosphere. These are smaller in amplitude and period when compared to most ionospheric disturbances and hence more difficult to measure. Very little is known about the properties of the travelling ionospheric disturbances (TIDs) over the Southern Hemisphere regions since studies have been conducted mostly over the Northern Hemisphere regions. This study presents a framework, using a High Frequency (HF) Doppler radar to investigate the physical properties and the possible driving mechanisms of TIDs. This research focuses on studying the characteristics of the TIDs, such as period, velocity and temporal variations, using HF Doppler measurements taken in South Africa. By making use of a Wavelet Analysis technique, the TIDs’ characteristics were determined. A statistical summary on speed and direction of propagation of the observed TIDs was performed. The winter medium scale travelling ionospheric disturbances (MSTIDs) observed are generally faster than the summer MSTIDs. For all seasons, the MSTIDs had a preferred south-southwest direction of propagation. Most of the large scale travelling ionospheric disturbances (LSTIDs) were observed during the night and of these, the spring LSTIDs were fastest when compared to autumn and summer LSTIDs. The general direction of travel of the observed LSTIDs is south-southeast. Total Electron Content (TEC), derived from Global Positioning System (GPS) measurements, were used to validate some of the TID results obtained from the HF Doppler data. The Horizontal Wind Model (HWM07), magnetic K index, and solar terminators were used to determine the possible sources of the observed TIDs. Only 41% of the observed TIDs were successfully linked to their possible sources of excitation. The information gathered from this study will be valuable in future radio communications and will serve as means to improve the existing ionospheric models over the South African region.
- Full Text:
- Date Issued: 2015
Monitoring carbon stocks in the sub-tropical thicket biome using remote sensing and GIS techniques : the case of the Great Fish River Nature Reserve and its environs, Eastern Cape province, South Africa
- Authors: Nyamugama, Adolph
- Date: 2013
- Subjects: Fragmented landscapes -- South Africa -- Eastern Cape -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10672 , http://hdl.handle.net/10948/d1020303
- Description: The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.
- Full Text:
- Date Issued: 2013
- Authors: Nyamugama, Adolph
- Date: 2013
- Subjects: Fragmented landscapes -- South Africa -- Eastern Cape -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10672 , http://hdl.handle.net/10948/d1020303
- Description: The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.
- Full Text:
- Date Issued: 2013
GIS implementation as a decision support tool for planning and managing development interventions
- Authors: Jong, Yungong Theophilus
- Date: 2011
- Subjects: Geographic information systems , Decision support systems , Enterprise resource planning , Spatial systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9257 , http://hdl.handle.net/10948/d1021227
- Description: The aim of this study is to examine key implementation and managerial issues surrounding the use of a Geographic Information Systems (GIS) as a Decisions Support Tool (DST) for planning and managing development interventions. Ever since the emergence of GIS as a powerful analytical tool in almost all spheres of human endeavour, many organisations involved in development work have adopted its use. But the challenges of conceiving and implementing a GIS in ways that are more responsive to the problems that trigger its purchase remains a daunting task to many development organisations; even those with a wealth of experience in GIS. This is one of the motivating factors for this study. In this research, some relevant themes in GIS implementation and GIS management as a Spatial Decision Support System (SDSS) were examined in the literature review. A case study research strategy was used focusing on the experience of the Nelson Mandela Bay Municipality Enterprise GIS (EGIS). The study examined how the system is been ran and what other development organisations can learn from this experience. Data was collected and analysed using a mixed research methods approach. The findings show a good level of GIS acceptance among municipality staff. However, running the system is not hitch free. A couple of problems and challenges were identified on the field. It is recommended that the municipality like most development organisations seeking GIS solutions should put the user at the centre of every technical innovation in GIS as a DST.
- Full Text:
- Date Issued: 2011
- Authors: Jong, Yungong Theophilus
- Date: 2011
- Subjects: Geographic information systems , Decision support systems , Enterprise resource planning , Spatial systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9257 , http://hdl.handle.net/10948/d1021227
- Description: The aim of this study is to examine key implementation and managerial issues surrounding the use of a Geographic Information Systems (GIS) as a Decisions Support Tool (DST) for planning and managing development interventions. Ever since the emergence of GIS as a powerful analytical tool in almost all spheres of human endeavour, many organisations involved in development work have adopted its use. But the challenges of conceiving and implementing a GIS in ways that are more responsive to the problems that trigger its purchase remains a daunting task to many development organisations; even those with a wealth of experience in GIS. This is one of the motivating factors for this study. In this research, some relevant themes in GIS implementation and GIS management as a Spatial Decision Support System (SDSS) were examined in the literature review. A case study research strategy was used focusing on the experience of the Nelson Mandela Bay Municipality Enterprise GIS (EGIS). The study examined how the system is been ran and what other development organisations can learn from this experience. Data was collected and analysed using a mixed research methods approach. The findings show a good level of GIS acceptance among municipality staff. However, running the system is not hitch free. A couple of problems and challenges were identified on the field. It is recommended that the municipality like most development organisations seeking GIS solutions should put the user at the centre of every technical innovation in GIS as a DST.
- Full Text:
- Date Issued: 2011
Adaptive user interfaces for mobile map-based visualisation
- Authors: Van Tonder, Bradley Paul
- Date: 2008
- Subjects: Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10470 , http://hdl.handle.net/10948/866 , Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Description: Mobile devices today frequently serve as platforms for the visualisation of map-based data. Despite the obvious advantages, mobile map-based visualisation (MMV) systems are often difficult to design and use. Limited screen space, resource constraints and awkward interaction mechanisms are among the many problems with which designers and users have to contend. Adaptive user interfaces (AUIs), which adapt to the individual user, represent a possible means of addressing the problems of MMV. Adaptive MMV systems are, however, generally designed in an ad-hoc fashion, making the benefits achieved difficult to replicate. In addition, existing models for adaptive MMV systems are either conceptual in nature or only address a subset of the possible input variables and adaptation effects. The primary objective of this research was to develop and evaluate an adaptive MMV system using a model-based approach. The Proteus Model was proposed to support the design of MMV systems which adapt in terms of information, visualisation and user interface in response to the user‟s behaviour, tasks and context. The Proteus Model describes the architectural, interface, data and algorithm design of an adaptive MMV system. A prototype adaptive MMV system, called MediaMaps, was designed and implemented based on the Proteus Model. MediaMaps allows users to capture, location-tag, organise and visualise multimedia on their mobile phones. Information adaptation is performed through the use of an algorithm to assist users in sorting media items into collections based on time and location. Visualisation adaptation is performed by adapting various parameters of the map-based visualisations according to user preferences. Interface adaptation is performed through the use of adaptive lists. An international field study of MediaMaps was conducted in which participants were required to use MediaMaps on their personal mobile phones for a period of three weeks. The results of the field study showed that high levels of accuracy were achieved by both the information and interface adaptations. High levels of user satisfaction were reported, with participants rating all three forms of adaptation as highly useful. The successful implementation of MediaMaps provides practical evidence that the model-based design of adaptive MMV systems is feasible. The positive results of the field study clearly show that the adaptations implemented were highly accurate and that participants found these adaptations to be useful, usable and easy to understand. This research thus provides empirical evidence that the use of AUIs can provide significant benefits for the visualisation of map-based information on mobile devices.
- Full Text:
- Date Issued: 2008
- Authors: Van Tonder, Bradley Paul
- Date: 2008
- Subjects: Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10470 , http://hdl.handle.net/10948/866 , Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Description: Mobile devices today frequently serve as platforms for the visualisation of map-based data. Despite the obvious advantages, mobile map-based visualisation (MMV) systems are often difficult to design and use. Limited screen space, resource constraints and awkward interaction mechanisms are among the many problems with which designers and users have to contend. Adaptive user interfaces (AUIs), which adapt to the individual user, represent a possible means of addressing the problems of MMV. Adaptive MMV systems are, however, generally designed in an ad-hoc fashion, making the benefits achieved difficult to replicate. In addition, existing models for adaptive MMV systems are either conceptual in nature or only address a subset of the possible input variables and adaptation effects. The primary objective of this research was to develop and evaluate an adaptive MMV system using a model-based approach. The Proteus Model was proposed to support the design of MMV systems which adapt in terms of information, visualisation and user interface in response to the user‟s behaviour, tasks and context. The Proteus Model describes the architectural, interface, data and algorithm design of an adaptive MMV system. A prototype adaptive MMV system, called MediaMaps, was designed and implemented based on the Proteus Model. MediaMaps allows users to capture, location-tag, organise and visualise multimedia on their mobile phones. Information adaptation is performed through the use of an algorithm to assist users in sorting media items into collections based on time and location. Visualisation adaptation is performed by adapting various parameters of the map-based visualisations according to user preferences. Interface adaptation is performed through the use of adaptive lists. An international field study of MediaMaps was conducted in which participants were required to use MediaMaps on their personal mobile phones for a period of three weeks. The results of the field study showed that high levels of accuracy were achieved by both the information and interface adaptations. High levels of user satisfaction were reported, with participants rating all three forms of adaptation as highly useful. The successful implementation of MediaMaps provides practical evidence that the model-based design of adaptive MMV systems is feasible. The positive results of the field study clearly show that the adaptations implemented were highly accurate and that participants found these adaptations to be useful, usable and easy to understand. This research thus provides empirical evidence that the use of AUIs can provide significant benefits for the visualisation of map-based information on mobile devices.
- Full Text:
- Date Issued: 2008
The use of Landsat ETM imagery as a suitable data capture source for alien acacia species for the WFW programme
- Authors: Cobbing, Benedict Louis
- Date: 2007
- Subjects: Geographic information systems , Global Positioning System , Landsat satellites , Agriculture -- Remote sensing , Geography -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4856 , http://hdl.handle.net/10962/d1005532 , Geographic information systems , Global Positioning System , Landsat satellites , Agriculture -- Remote sensing , Geography -- Remote sensing
- Description: Geographic Information System technology today allows for the rapid analysis of vast amounts of spatial and non-spatial data. The power of a GIS can only be effected with the rapid collection of accurate input data. This is particularly true in the case of the South African National Working for Water (WFW) Programme where large volumes of spatial data on alien vegetation infestations are captured throughout the country. Alien vegetation clearing contracts cannot be generated, for WFW, without this data, so that the accurate capture of such data is crucial to the success of the programme. Mapping Invasive Alien Plant (IAP) data within WFW is a perennial problem (Coetzee, pers com, 2002), because not enough mapping is being done to meet the annual requirements of the programme in the various provinces. This is re-iterated by Richardson, 2004, who states that there is a shortage of accurate data on IAP abundance in South Africa. Therefore there is a need to investigate alternate methods of data capture; such as remote sensing, whilst working within the existing WFW data capture standards. The aim of this research was to investigate the use of Landsat ETM imagery as a data capture source for mapping alien vegetation for the WFW Programme in terms of their approved mapping methods, for both automated and manual classification techniques. The automated and manual classification results were compared to control data captured by differential Global Positioning Systems (DGPS). The research tested the various methods of data capture using Landsat ETM images over a range of study sites of varying complexity: a simple grassland area, a medium complexity grassy fynbos site and a complicated indigenous forest site. An important component of the research was to develop a mapping (classification) Ranking System based upon variables identified by WFW as fundamental in data capture decision making: spatial and positional accuracy, time constraints and cost constraints for three typical alien invaded areas. The mapping Ranking System compared the results of the various mapping methods for each factor for the study sites against each other. This provided an indication of which mapping method is the most efficient or suitable for a particular area.
- Full Text:
- Date Issued: 2007
- Authors: Cobbing, Benedict Louis
- Date: 2007
- Subjects: Geographic information systems , Global Positioning System , Landsat satellites , Agriculture -- Remote sensing , Geography -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4856 , http://hdl.handle.net/10962/d1005532 , Geographic information systems , Global Positioning System , Landsat satellites , Agriculture -- Remote sensing , Geography -- Remote sensing
- Description: Geographic Information System technology today allows for the rapid analysis of vast amounts of spatial and non-spatial data. The power of a GIS can only be effected with the rapid collection of accurate input data. This is particularly true in the case of the South African National Working for Water (WFW) Programme where large volumes of spatial data on alien vegetation infestations are captured throughout the country. Alien vegetation clearing contracts cannot be generated, for WFW, without this data, so that the accurate capture of such data is crucial to the success of the programme. Mapping Invasive Alien Plant (IAP) data within WFW is a perennial problem (Coetzee, pers com, 2002), because not enough mapping is being done to meet the annual requirements of the programme in the various provinces. This is re-iterated by Richardson, 2004, who states that there is a shortage of accurate data on IAP abundance in South Africa. Therefore there is a need to investigate alternate methods of data capture; such as remote sensing, whilst working within the existing WFW data capture standards. The aim of this research was to investigate the use of Landsat ETM imagery as a data capture source for mapping alien vegetation for the WFW Programme in terms of their approved mapping methods, for both automated and manual classification techniques. The automated and manual classification results were compared to control data captured by differential Global Positioning Systems (DGPS). The research tested the various methods of data capture using Landsat ETM images over a range of study sites of varying complexity: a simple grassland area, a medium complexity grassy fynbos site and a complicated indigenous forest site. An important component of the research was to develop a mapping (classification) Ranking System based upon variables identified by WFW as fundamental in data capture decision making: spatial and positional accuracy, time constraints and cost constraints for three typical alien invaded areas. The mapping Ranking System compared the results of the various mapping methods for each factor for the study sites against each other. This provided an indication of which mapping method is the most efficient or suitable for a particular area.
- Full Text:
- Date Issued: 2007
GIS in participatory catchment management : a case study in the Kat River Valley, Eastern Cape, South Africa
- Authors: McMaster, Alistair
- Date: 2002 , 2013-05-16
- Subjects: Watershed management -- South Africa -- Eastern Cape , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4868 , http://hdl.handle.net/10962/d1007602 , Watershed management -- South Africa -- Eastern Cape , Geographic information systems
- Description: In water resources management in South Africa, there is an emphasis on public participation. On a river catchment basis, one of the mechanisms for such participation is the establishment of catchment forums. However, members of catchment forums, particularly those coming from poor or rural communities, cannot be expected to engage in catchment management without having been enabled to do so. This thesis considers the use of GIS in the process of enabling the Kat River Valley Catchment Forum to better participate in catchment management. The research focus is on the use of GIS to facilitate an understanding of the Kat River Catchment and associated catchment concepts, and constructive communication and sharing, among the Catchment Forum. The GIS is used in the context of "GIS for Participatory Research", an outgrowth of Public Participation GIS (PPGIS), which focuses on GIS as a tool for empowerment within participatory processes. The study has used Action Research, situated in the Critical paradigm, as a methodology. The research has included seven Forum workshop processes and one series of in-village meetings. These engagements have involved map-based appraisals, issues and resource mapping, map-based planning, and the use of on-screen GIS for presentation and sharing. The use of GIS has facilitated the creation of customised maps, the integration of village-scale mapping into a catchment scale product, the presentation of synthesised data in digital and hardcopy format and, in so doing, has allowed catchment-scale appraisal. Outcomes enabling participation in catchment management have included developed mapping skills and an enhanced understanding of the catchment as a whole, and developed conceptual access to a decision-making language (or way of thinking), among participants. Furthermore, the Forum as a whole has identified common needs, and has developed a set of map-based action plans. The research process has yielded a number of lessons regarding "GIS for participation" and the participatory framework within which it takes place. Chief among these is that the GIS operator should take on the role of a participatory practitioner.
- Full Text:
- Date Issued: 2002
- Authors: McMaster, Alistair
- Date: 2002 , 2013-05-16
- Subjects: Watershed management -- South Africa -- Eastern Cape , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4868 , http://hdl.handle.net/10962/d1007602 , Watershed management -- South Africa -- Eastern Cape , Geographic information systems
- Description: In water resources management in South Africa, there is an emphasis on public participation. On a river catchment basis, one of the mechanisms for such participation is the establishment of catchment forums. However, members of catchment forums, particularly those coming from poor or rural communities, cannot be expected to engage in catchment management without having been enabled to do so. This thesis considers the use of GIS in the process of enabling the Kat River Valley Catchment Forum to better participate in catchment management. The research focus is on the use of GIS to facilitate an understanding of the Kat River Catchment and associated catchment concepts, and constructive communication and sharing, among the Catchment Forum. The GIS is used in the context of "GIS for Participatory Research", an outgrowth of Public Participation GIS (PPGIS), which focuses on GIS as a tool for empowerment within participatory processes. The study has used Action Research, situated in the Critical paradigm, as a methodology. The research has included seven Forum workshop processes and one series of in-village meetings. These engagements have involved map-based appraisals, issues and resource mapping, map-based planning, and the use of on-screen GIS for presentation and sharing. The use of GIS has facilitated the creation of customised maps, the integration of village-scale mapping into a catchment scale product, the presentation of synthesised data in digital and hardcopy format and, in so doing, has allowed catchment-scale appraisal. Outcomes enabling participation in catchment management have included developed mapping skills and an enhanced understanding of the catchment as a whole, and developed conceptual access to a decision-making language (or way of thinking), among participants. Furthermore, the Forum as a whole has identified common needs, and has developed a set of map-based action plans. The research process has yielded a number of lessons regarding "GIS for participation" and the participatory framework within which it takes place. Chief among these is that the GIS operator should take on the role of a participatory practitioner.
- Full Text:
- Date Issued: 2002
RADGIS - an improved architecture for runtime-extensible, distributed GIS applications
- Authors: Preston, Richard Michael
- Date: 2002
- Subjects: Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4626 , http://hdl.handle.net/10962/d1006497
- Description: A number of GIS architectures and technologies have emerged recently to facilitate the visualisation and processing of geospatial data over the Web. The work presented in this dissertation builds on these efforts and undertakes to overcome some of the major problems with traditional GIS client architectures, including application bloat, lack of customisability, and lack of interoperability between GIS products. In this dissertation we describe how a new client-side GIS architecture was developed and implemented as a proof-of-concept application called RADGIS, which is based on open standards and emerging distributed component-based software paradigms. RADGIS reflects the current trend in development focus from Web browser-based applications to customised clients, based on open standards, that make use of distributed Web services. While much attention has been paid to exposing data on the Web, there is growing momentum towards providing “value-added” services. A good example of this is the tremendous industry interest in the provision of location-based services, which has been discussed as a special use-case of our RADGIS architecture. Thus, in the near future client applications will not simply be used to access data transparently, but will also become facilitators for the location-transparent invocation of local and remote services. This flexible architecture will ensure that data can be stored and processed independently of the location of the client that wishes to view or interact with it. Our RADGIS application enables content developers and end-users to create and/or customise GIS applications dynamically at runtime through the incorporation of GIS services. This ensures that the client application has the flexibility to withstand changing levels of expertise or user requirements. These GIS services are implemented as components that execute locally on the client machine, or as remote CORBA Objects or EJBs. Assembly and deployment of these components is achieved using a specialised XML descriptor. This XML descriptor is written using a markup language that we developed specifically for this purpose, called DGCML, which contains deployment information, as well as a GUI specification and links to an XML-based help system that can be merged with the RADGIS client application’s existing help system. Thus, no additional requirements are imposed on object developers by the RADGIS architecture, i.e. there is no need to rewrite existing objects since DGCML acts as a runtime-customisable wrapper, allowing existing objects to be utilised by RADGIS. While the focus of this thesis has been on overcoming the above-mentioned problems with traditional GIS applications, the work described here can also be applied in a much broader context, especially in the development of highly customisable client applications that are able to integrate Web services at runtime.
- Full Text:
- Date Issued: 2002
- Authors: Preston, Richard Michael
- Date: 2002
- Subjects: Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4626 , http://hdl.handle.net/10962/d1006497
- Description: A number of GIS architectures and technologies have emerged recently to facilitate the visualisation and processing of geospatial data over the Web. The work presented in this dissertation builds on these efforts and undertakes to overcome some of the major problems with traditional GIS client architectures, including application bloat, lack of customisability, and lack of interoperability between GIS products. In this dissertation we describe how a new client-side GIS architecture was developed and implemented as a proof-of-concept application called RADGIS, which is based on open standards and emerging distributed component-based software paradigms. RADGIS reflects the current trend in development focus from Web browser-based applications to customised clients, based on open standards, that make use of distributed Web services. While much attention has been paid to exposing data on the Web, there is growing momentum towards providing “value-added” services. A good example of this is the tremendous industry interest in the provision of location-based services, which has been discussed as a special use-case of our RADGIS architecture. Thus, in the near future client applications will not simply be used to access data transparently, but will also become facilitators for the location-transparent invocation of local and remote services. This flexible architecture will ensure that data can be stored and processed independently of the location of the client that wishes to view or interact with it. Our RADGIS application enables content developers and end-users to create and/or customise GIS applications dynamically at runtime through the incorporation of GIS services. This ensures that the client application has the flexibility to withstand changing levels of expertise or user requirements. These GIS services are implemented as components that execute locally on the client machine, or as remote CORBA Objects or EJBs. Assembly and deployment of these components is achieved using a specialised XML descriptor. This XML descriptor is written using a markup language that we developed specifically for this purpose, called DGCML, which contains deployment information, as well as a GUI specification and links to an XML-based help system that can be merged with the RADGIS client application’s existing help system. Thus, no additional requirements are imposed on object developers by the RADGIS architecture, i.e. there is no need to rewrite existing objects since DGCML acts as a runtime-customisable wrapper, allowing existing objects to be utilised by RADGIS. While the focus of this thesis has been on overcoming the above-mentioned problems with traditional GIS applications, the work described here can also be applied in a much broader context, especially in the development of highly customisable client applications that are able to integrate Web services at runtime.
- Full Text:
- Date Issued: 2002
An appraisal of the production and utility of digital atlases in Africa: a case study of Swaziland
- Authors: Pettit, Louise Manda
- Date: 2000
- Subjects: Swaziland Atlases , Digital mapping , Geographic information systems , Cartography -- Data processing , Cartography -- Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4816 , http://hdl.handle.net/10962/d1005490 , Swaziland Atlases , Digital mapping , Geographic information systems , Cartography -- Data processing , Cartography -- Africa
- Description: This research will appraise the production and utility of digital atlases in an African context, using personal experience gained through the production of a digital atlas for Swaziland, the opinions obtained from other producers of African digital atlases and relevant literature. Since the 1950s, decision makers and researchers have viewed information as a powerful contributor to national development. Over the past thirty years, developed countries have increased the efficient collation and dissemination of geographic information through the utilization of the digital environment. The development of Geographic Information Systems (GIS) has increased the range of applications attainable in digital mapping projects. Applications have ranged from resource inventories to the monitoring of environmental degradation, crime patterns and service provision. The patchy history of data collection, analysis and mapping in Africa, has had a limiting effect on the ability of countries to identify, plan and control their resources efficiently. Despite the desire to automate the mapping process and reap some of the planning benefits evident in the developed world, Africa has not succeeded in mobilising full technological potential. Political instability, poor infrastructure, the absence of national policy guidelines, and a lack of skilled manpower are some of the issues which have limited utilization. Despite many of the hurdles faced by African countries, automated mapping and analysis technologies are still being pursued. The role of computers in the utilisation of data has become apparent through several means, one of which is the digital atlas. Analytical functions in many of these products allow situation modelling and provide superior graphic displays in comparison to their paper counterparts. Several African countries have embarked on the development of national digital databases and in some cases have produced digital national atlases. The potential to improve resource utilization, service provision and land use planning using these atlases, does exist. The production and utility of these atlases in an African context, however, needs closer assessment. "Computers don't clothe, don't cure, don't feed. Their power begins and ends with information. Their usefulness is therefore strictly linked to the ffectiveness of the information" (Gardner,1993:16).
- Full Text:
- Date Issued: 2000
- Authors: Pettit, Louise Manda
- Date: 2000
- Subjects: Swaziland Atlases , Digital mapping , Geographic information systems , Cartography -- Data processing , Cartography -- Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4816 , http://hdl.handle.net/10962/d1005490 , Swaziland Atlases , Digital mapping , Geographic information systems , Cartography -- Data processing , Cartography -- Africa
- Description: This research will appraise the production and utility of digital atlases in an African context, using personal experience gained through the production of a digital atlas for Swaziland, the opinions obtained from other producers of African digital atlases and relevant literature. Since the 1950s, decision makers and researchers have viewed information as a powerful contributor to national development. Over the past thirty years, developed countries have increased the efficient collation and dissemination of geographic information through the utilization of the digital environment. The development of Geographic Information Systems (GIS) has increased the range of applications attainable in digital mapping projects. Applications have ranged from resource inventories to the monitoring of environmental degradation, crime patterns and service provision. The patchy history of data collection, analysis and mapping in Africa, has had a limiting effect on the ability of countries to identify, plan and control their resources efficiently. Despite the desire to automate the mapping process and reap some of the planning benefits evident in the developed world, Africa has not succeeded in mobilising full technological potential. Political instability, poor infrastructure, the absence of national policy guidelines, and a lack of skilled manpower are some of the issues which have limited utilization. Despite many of the hurdles faced by African countries, automated mapping and analysis technologies are still being pursued. The role of computers in the utilisation of data has become apparent through several means, one of which is the digital atlas. Analytical functions in many of these products allow situation modelling and provide superior graphic displays in comparison to their paper counterparts. Several African countries have embarked on the development of national digital databases and in some cases have produced digital national atlases. The potential to improve resource utilization, service provision and land use planning using these atlases, does exist. The production and utility of these atlases in an African context, however, needs closer assessment. "Computers don't clothe, don't cure, don't feed. Their power begins and ends with information. Their usefulness is therefore strictly linked to the ffectiveness of the information" (Gardner,1993:16).
- Full Text:
- Date Issued: 2000
The development of a geographic information systems based atlas of southern African freshwater fish, and its application to biogeographic analysis
- Scott, Lucy Elizabeth Powell
- Authors: Scott, Lucy Elizabeth Powell
- Date: 2000
- Subjects: Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5256 , http://hdl.handle.net/10962/d1005099 , Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Description: A Geographic Information Systems (GIS) atlas of southern African freshwater fish was developed for the SADC countries from natural history collection specimens, hydrological, topographical and climatological data. The primary purpose of the development of the atlas of freshwater fish was the construction of a practical framework to transform vast amounts of existing biological data for use in research and management of aquatic resources. The database of freshwater fish collection specimens that was incorporated into the atlas, was developed in association with ALCOM (Aquatic Resources Management for Local Community Development Programme). The development of advanced computing and GIS technology has increased the scope of biological atlas projects by facilitating the integration of large amounts of spatial data to produce derived databases for specific applications. The atlas of freshwater fish was constructed using TNTmips GIS software as the most practical system available for managing and analysing biological data with a spatial component. The atlas contains 35 180 comprehensive distribution records of 735 species of fish. It has many applications as an inventory of ichthyofaunal spatial biodiversity, including those of conservation planning, environmental assessment and biogeographic research. Biogeographic studies have traditionally been subjective due to the logistical problems of working with large amounts of distribution data, although some small-scale quantitative research has been carried out in the past. The content of the atlas of freshwater fish is tested with respect to these previous studies, on known patterns of freshwater fish distributions, and the analytical capability of the atlas is tested and demonstrated with some new preliminary approaches to the analysis of freshwater fish distributions in southern Africa.
- Full Text:
- Date Issued: 2000
- Authors: Scott, Lucy Elizabeth Powell
- Date: 2000
- Subjects: Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5256 , http://hdl.handle.net/10962/d1005099 , Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Description: A Geographic Information Systems (GIS) atlas of southern African freshwater fish was developed for the SADC countries from natural history collection specimens, hydrological, topographical and climatological data. The primary purpose of the development of the atlas of freshwater fish was the construction of a practical framework to transform vast amounts of existing biological data for use in research and management of aquatic resources. The database of freshwater fish collection specimens that was incorporated into the atlas, was developed in association with ALCOM (Aquatic Resources Management for Local Community Development Programme). The development of advanced computing and GIS technology has increased the scope of biological atlas projects by facilitating the integration of large amounts of spatial data to produce derived databases for specific applications. The atlas of freshwater fish was constructed using TNTmips GIS software as the most practical system available for managing and analysing biological data with a spatial component. The atlas contains 35 180 comprehensive distribution records of 735 species of fish. It has many applications as an inventory of ichthyofaunal spatial biodiversity, including those of conservation planning, environmental assessment and biogeographic research. Biogeographic studies have traditionally been subjective due to the logistical problems of working with large amounts of distribution data, although some small-scale quantitative research has been carried out in the past. The content of the atlas of freshwater fish is tested with respect to these previous studies, on known patterns of freshwater fish distributions, and the analytical capability of the atlas is tested and demonstrated with some new preliminary approaches to the analysis of freshwater fish distributions in southern Africa.
- Full Text:
- Date Issued: 2000
A collated digital, geological map database for the central Namaqua Province using geographical information system technology
- Authors: Holland, Henry
- Date: 1997
- Subjects: Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4936 , http://hdl.handle.net/10962/d1005548 , Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Description: The genlogy of the Namaqua Province is notoriously difficult to map and interpret due to polymetamorphic and multiple deformation events and limlted outcrop. Current maps of the Province reflect diverse interpretations of stratigraphy as a consequence of these difficulties. A Geographic Information System is essentially a digital database and a set of functions and procedures to capture, analyse and manipulate spatially related data. A GIS is therefore ideally suited to the study and analysis of maps. A digital map database was established, using modem GIS technology, to facilitate the collation of existing maps of an area in the Central Namaqua Province (CNP). This database is based on a lithological classification system similar to that used by Harris (1992), rather than on an interpretive stratigraphic model. In order to establish the database, existing geological maps were scanned into a GIS, and lines of outcrop and lithological contacts were digitised using a manual line following process, which is one of the functions native to a GIS. Attribute data were then attached to the resultant polygons. The attribute database consists of lithological, textural and mineralogical data, as well as stratigraphical classification data according to the South African Committee for Stratigraphy (SACS), correlative names assigned to units by the Precambrian Research Unit, the Geological Survey of South Africa, the Bushmanland Research group and the University of the Orange Free State. Other attribute data included in the database, are tectonic and absolute age information, and the terrane classification for the area. This database reflects the main objective of the project and also serves as a basis for further expansion of a geological GIS for the CNP. Cartographic and database capabilities of the GIS were employed to produce a collated lithological map of the CNP. A TNTmipsTM Spatial Manipulation Language routine was written to produce a database containing two fields linked to each polygon, one for lithology and one for a correlation probability factor. Correlation factors are calculated in this routine from three variables, namely the prominence a worker attached to a specific lithology within a unit or outcrop, the agreement amongst the various workers on the actual lithology present within an outcrop, and the correspondence between the source of the spatial element (mapped outcrop) and the source of the attribute data attached to it. Outcrops were displayed on the map according to the lithology with the highest correlation factor, providing a unique view of the spatial relationships and distribution patterns of lithological units in the CNP. A second map was produced indicating the correlation factors for lithologies within the CNP. Thematic maps are produced in a GIS by selecting spatial elements according to a set of criteria, usually based on the attribute database, and then displaying the elements as maps. Maps created by this process are known as customised maps, since users of the GIS can customise the selection and display of elements according to their needs. For instance, all outcrops of rock units containing particular lithologies of a given age occurring in a specific terrane can be displayed - either on screen or printed out as a map. The database also makes it possible to plot maps according to different stratigraphic classification systems. Areas where various workers disagree on the stratigraphic classification of units can be isolated, and displayed as separate maps in order to aid in the collation process. The database can assist SACS in identifying areas in the CNP where stratigraphic classification is still lacking or agreements on stratigraphic nomenclature have not yet been attained. More than one database can be attached to the spatial elements in a GIS, and the Namaqua-GIS can therefore be expanded to include geochemical, geophysical, economic, structural and geographical data. Other data on the area, such as more detailed maps, photographs and satellite images can be attached to the lithological map database in the correct spatial relationship. Another advantage of a GIS is the facility to continually update the database(s) as more information becomes available and/or as interpretation of the area is refined.
- Full Text:
- Date Issued: 1997
- Authors: Holland, Henry
- Date: 1997
- Subjects: Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4936 , http://hdl.handle.net/10962/d1005548 , Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Description: The genlogy of the Namaqua Province is notoriously difficult to map and interpret due to polymetamorphic and multiple deformation events and limlted outcrop. Current maps of the Province reflect diverse interpretations of stratigraphy as a consequence of these difficulties. A Geographic Information System is essentially a digital database and a set of functions and procedures to capture, analyse and manipulate spatially related data. A GIS is therefore ideally suited to the study and analysis of maps. A digital map database was established, using modem GIS technology, to facilitate the collation of existing maps of an area in the Central Namaqua Province (CNP). This database is based on a lithological classification system similar to that used by Harris (1992), rather than on an interpretive stratigraphic model. In order to establish the database, existing geological maps were scanned into a GIS, and lines of outcrop and lithological contacts were digitised using a manual line following process, which is one of the functions native to a GIS. Attribute data were then attached to the resultant polygons. The attribute database consists of lithological, textural and mineralogical data, as well as stratigraphical classification data according to the South African Committee for Stratigraphy (SACS), correlative names assigned to units by the Precambrian Research Unit, the Geological Survey of South Africa, the Bushmanland Research group and the University of the Orange Free State. Other attribute data included in the database, are tectonic and absolute age information, and the terrane classification for the area. This database reflects the main objective of the project and also serves as a basis for further expansion of a geological GIS for the CNP. Cartographic and database capabilities of the GIS were employed to produce a collated lithological map of the CNP. A TNTmipsTM Spatial Manipulation Language routine was written to produce a database containing two fields linked to each polygon, one for lithology and one for a correlation probability factor. Correlation factors are calculated in this routine from three variables, namely the prominence a worker attached to a specific lithology within a unit or outcrop, the agreement amongst the various workers on the actual lithology present within an outcrop, and the correspondence between the source of the spatial element (mapped outcrop) and the source of the attribute data attached to it. Outcrops were displayed on the map according to the lithology with the highest correlation factor, providing a unique view of the spatial relationships and distribution patterns of lithological units in the CNP. A second map was produced indicating the correlation factors for lithologies within the CNP. Thematic maps are produced in a GIS by selecting spatial elements according to a set of criteria, usually based on the attribute database, and then displaying the elements as maps. Maps created by this process are known as customised maps, since users of the GIS can customise the selection and display of elements according to their needs. For instance, all outcrops of rock units containing particular lithologies of a given age occurring in a specific terrane can be displayed - either on screen or printed out as a map. The database also makes it possible to plot maps according to different stratigraphic classification systems. Areas where various workers disagree on the stratigraphic classification of units can be isolated, and displayed as separate maps in order to aid in the collation process. The database can assist SACS in identifying areas in the CNP where stratigraphic classification is still lacking or agreements on stratigraphic nomenclature have not yet been attained. More than one database can be attached to the spatial elements in a GIS, and the Namaqua-GIS can therefore be expanded to include geochemical, geophysical, economic, structural and geographical data. Other data on the area, such as more detailed maps, photographs and satellite images can be attached to the lithological map database in the correct spatial relationship. Another advantage of a GIS is the facility to continually update the database(s) as more information becomes available and/or as interpretation of the area is refined.
- Full Text:
- Date Issued: 1997
The application of a landscape diversity index using remote sensing and geographical information systems to identify degradation patterns in the Great Fish River Valley, Eastern Cape Province, South Africa
- Authors: Tanser, Frank Courteney
- Date: 1997
- Subjects: Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4814 , http://hdl.handle.net/10962/d1005488 , Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Description: Using a range of satellite-derived indices I describe. monitor and predict vegetation conditions that exist in the Great Fish River Valley, Eastern Cape. The heterogeneous nature of the area necessitates that the mapping of vegetation classes be accomplished using a combination of a supervised approach, an unsupervised approach and the use of a Moving Standard Deviation Index (MSDI). Nine vegetation classes are identified and mapped at an accuracy of 84%. The vegetation classes are strongly related to land-use and the communal areas demonstrate a reduction in palatable species and a shift towards dominance by a single species. Nature reserves and commercial rangeland are by contrast dominated by good condition vegetation types. The Modified Soil Adjusted Vegetation Index (MSA VI) is used to map the vegetation production in the study area. The influence of soil reflectance is reduced using this index. The MSA VI proves to be a good predictor of vegetation condition in the higher rainfall areas but not in the more semi-arid regions. The MSA VI has a significant relationship to rainfall but no absolute relationship to biomass. However, a stratification approach (on the basis of vegetation type) reveals that the MSA VI exhibits relationships to biomass in vegetation types occurring in the higher rainfall areas and consisting of a large cover of shrubs. A technique based on an index which describes landscape spatial variability is presented to assist in the interpretation of landscape condition. The research outlines a method for degradation assessment which overcomes many of the problems associated with cost and repeatability. Indices that attempt to provide a correlation with net primary productivity, e.g. NDVI, do not consider changes in the quality of net primary productivity. Landscape variability represents a measure of ecosystem change in the landscape that underlies the degradation process. The hypothesis is that healthy/undisturbed/stable landscapes tend to be less variable and homogenous than their degraded heterogenous counterparts. The Moving Standard Deviation Index (MSDI) is calculated by performing a 3 x 3 moving standard deviation window across Landsat Thematic Mapper (TM) band 3. The result is a sensitive indicator of landscape condition which is not affected by moisture availability and vegetation type. The MSDI shows a significant negative relationship to NDVI confirming its relationship to condition. The cross-classification of MSDI with NDVI allows the identification of invasive woody weeds which exhibit strong photosynthetic signals and would therefore be categorised as good condition using NDVI. Other ecosystems are investigated to determine the relationship between NDVI and MSDI. Where increase in NDVI is disturbance-induced (such as the Kalahari Desert) the relationship is positive. Where high NDVI values are indicative of good condition rangeland (such as the Fish River Valley) the relationship is negative. The MSDI therefore always exhibits a significant positive relationship to degradation irrespective of the relationship of NDVI to condition in the ecosystem.
- Full Text:
- Date Issued: 1997
- Authors: Tanser, Frank Courteney
- Date: 1997
- Subjects: Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4814 , http://hdl.handle.net/10962/d1005488 , Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Description: Using a range of satellite-derived indices I describe. monitor and predict vegetation conditions that exist in the Great Fish River Valley, Eastern Cape. The heterogeneous nature of the area necessitates that the mapping of vegetation classes be accomplished using a combination of a supervised approach, an unsupervised approach and the use of a Moving Standard Deviation Index (MSDI). Nine vegetation classes are identified and mapped at an accuracy of 84%. The vegetation classes are strongly related to land-use and the communal areas demonstrate a reduction in palatable species and a shift towards dominance by a single species. Nature reserves and commercial rangeland are by contrast dominated by good condition vegetation types. The Modified Soil Adjusted Vegetation Index (MSA VI) is used to map the vegetation production in the study area. The influence of soil reflectance is reduced using this index. The MSA VI proves to be a good predictor of vegetation condition in the higher rainfall areas but not in the more semi-arid regions. The MSA VI has a significant relationship to rainfall but no absolute relationship to biomass. However, a stratification approach (on the basis of vegetation type) reveals that the MSA VI exhibits relationships to biomass in vegetation types occurring in the higher rainfall areas and consisting of a large cover of shrubs. A technique based on an index which describes landscape spatial variability is presented to assist in the interpretation of landscape condition. The research outlines a method for degradation assessment which overcomes many of the problems associated with cost and repeatability. Indices that attempt to provide a correlation with net primary productivity, e.g. NDVI, do not consider changes in the quality of net primary productivity. Landscape variability represents a measure of ecosystem change in the landscape that underlies the degradation process. The hypothesis is that healthy/undisturbed/stable landscapes tend to be less variable and homogenous than their degraded heterogenous counterparts. The Moving Standard Deviation Index (MSDI) is calculated by performing a 3 x 3 moving standard deviation window across Landsat Thematic Mapper (TM) band 3. The result is a sensitive indicator of landscape condition which is not affected by moisture availability and vegetation type. The MSDI shows a significant negative relationship to NDVI confirming its relationship to condition. The cross-classification of MSDI with NDVI allows the identification of invasive woody weeds which exhibit strong photosynthetic signals and would therefore be categorised as good condition using NDVI. Other ecosystems are investigated to determine the relationship between NDVI and MSDI. Where increase in NDVI is disturbance-induced (such as the Kalahari Desert) the relationship is positive. Where high NDVI values are indicative of good condition rangeland (such as the Fish River Valley) the relationship is negative. The MSDI therefore always exhibits a significant positive relationship to degradation irrespective of the relationship of NDVI to condition in the ecosystem.
- Full Text:
- Date Issued: 1997
The use of remote sensing and Geographic Information System (GIS) techniques, to interpret savanna ecosystem patterns in the Sabi Sand Game Reserve, Mpumalanga province
- Fortescue, Alexander Kenneth John
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
An examination of the application of a geographical information system to rural development planning in Shixini Location, Transkei
- Authors: Whisken, Jarrell Braden
- Date: 1996
- Subjects: Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4830 , http://hdl.handle.net/10962/d1005505 , Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Description: Digital geographical information systems (GIS) are tools for handling spatial data. Initially developed in First World countries, the technology is fast being taken up as a tool for handling spatial information by many Third World countries. GIS has been used for any number of applications involving spatial data, one of its primary uses has been in various planning fields where the advantages offered to planners by the technology have been highlighted by a number of publications and studies. GIS has been actively used as an urban planning tool in South Africa since the mid-1980s, (Vosloo 1987) however its use as a tool for rural planning has not developed to the same extent. As early as 1986 reference was made to the possible advantages offered by GIS to rural planning in South Africa (Fincham 1986). Despite this early recognition, the use of GIS in the rural planning sphere remains negligible. This study examines the. possible reasons for this by attempting to answer the question, "is GIS appropriate to rural planning in South Africa?" A number of approaches to rural planning are practised in South Africa. This study examines the appropriateness of applying GIS to one of these approaches, rural community development planning. Components of the study included i) an examination of the issues affecting the use of GIS in the rural development field, achieved through the use of a literature and questionnaire survey and ii) a case study examining the feasibility of incorporating GIS as a tool to the Shixini Development Project, Transkei. The study does not examine the intricacies of rural development theory, but it does acknowledge the fact that the approach employed by an organisation to rural development will have important implications concerning the use of a GIS in a project. The approach adopted to a project affects amongst others the administrative structure, the planning process, the flow of spatial data and its use, and consequently the possible role of GIS. The Shixini Rural Development Project was classified as a community development project, and as a result the study concentrates on this approach to rural development. This may limit the study to a particular planning process, however most rural case studies will have certain aims and factors which are unique to its situation. In order to place the results of the Shixini case study in a wider context the results of the study are linked to the questionnaire and literature survey. From this basis the usefulness of GIS in the rural development sphere was examined. Available literature on GIS indicates that the majority of problems associated with GIS rarely reside with the technology itself but rather with its supporting mechanisms. The study identified and concentrated on these support mechanisms, both at the project level and what is referred to in the study as the operating environment in South Africa. The results of the study revealed that a number of problems exist with regard to the attitude with which GIS is regarded in development organisations. It was found that these attitudes are legitimately based on a number of problems associated with incorporating the technology into project based organisations. It was concluded that GIS was appropriate to rural community planning, but is presently limited to certain aspects of the planning process and possibly to certain applications.
- Full Text:
- Date Issued: 1996
- Authors: Whisken, Jarrell Braden
- Date: 1996
- Subjects: Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4830 , http://hdl.handle.net/10962/d1005505 , Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Description: Digital geographical information systems (GIS) are tools for handling spatial data. Initially developed in First World countries, the technology is fast being taken up as a tool for handling spatial information by many Third World countries. GIS has been used for any number of applications involving spatial data, one of its primary uses has been in various planning fields where the advantages offered to planners by the technology have been highlighted by a number of publications and studies. GIS has been actively used as an urban planning tool in South Africa since the mid-1980s, (Vosloo 1987) however its use as a tool for rural planning has not developed to the same extent. As early as 1986 reference was made to the possible advantages offered by GIS to rural planning in South Africa (Fincham 1986). Despite this early recognition, the use of GIS in the rural planning sphere remains negligible. This study examines the. possible reasons for this by attempting to answer the question, "is GIS appropriate to rural planning in South Africa?" A number of approaches to rural planning are practised in South Africa. This study examines the appropriateness of applying GIS to one of these approaches, rural community development planning. Components of the study included i) an examination of the issues affecting the use of GIS in the rural development field, achieved through the use of a literature and questionnaire survey and ii) a case study examining the feasibility of incorporating GIS as a tool to the Shixini Development Project, Transkei. The study does not examine the intricacies of rural development theory, but it does acknowledge the fact that the approach employed by an organisation to rural development will have important implications concerning the use of a GIS in a project. The approach adopted to a project affects amongst others the administrative structure, the planning process, the flow of spatial data and its use, and consequently the possible role of GIS. The Shixini Rural Development Project was classified as a community development project, and as a result the study concentrates on this approach to rural development. This may limit the study to a particular planning process, however most rural case studies will have certain aims and factors which are unique to its situation. In order to place the results of the Shixini case study in a wider context the results of the study are linked to the questionnaire and literature survey. From this basis the usefulness of GIS in the rural development sphere was examined. Available literature on GIS indicates that the majority of problems associated with GIS rarely reside with the technology itself but rather with its supporting mechanisms. The study identified and concentrated on these support mechanisms, both at the project level and what is referred to in the study as the operating environment in South Africa. The results of the study revealed that a number of problems exist with regard to the attitude with which GIS is regarded in development organisations. It was found that these attitudes are legitimately based on a number of problems associated with incorporating the technology into project based organisations. It was concluded that GIS was appropriate to rural community planning, but is presently limited to certain aspects of the planning process and possibly to certain applications.
- Full Text:
- Date Issued: 1996
Semi-automated extraction of structural orientation data from aerospace imagery combined with digital elevation models
- Authors: Slabber, Frans Bresler
- Date: 1996
- Subjects: Image processing , Geographic information systems , Information storage and retrieval systems -- Geology , Geology -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5001 , http://hdl.handle.net/10962/d1005614 , Image processing , Geographic information systems , Information storage and retrieval systems -- Geology , Geology -- Data processing
- Description: A computer-based method for determining the orientation of planar geological structures from remotely sensed images, utilizing digital geological images and digital elevation models (DEMs), is developed and assessed. The method relies on operator skill and experience to recognize geological structure traces on images, and then employs software routines (GEOSTRUC©) to calculate the orientation of selected structures. The operator selects three points on the trace of a planar geological feature as seen on a digital geological image that is co registered with a DEM of the same area. The orientation of the plane that contains the three points is determined using vector algebra equations. The program generates an ASCII data file which contains the orientation data as well as the geographical location of the measurements. This ASCII file can then be utilized in further analysis of the orientation data. The software development kit (SDK) for TNTmips v5.00, from MicroImages Inc. and operating in the X Windows environment, was employed to construct the software. The Watcom C\C++ Development Environment was used to generate the executable program, GEOSTRUC© . GEOSTRUC© was tested in two case studies. The case studies utilized digital data derived from the use of different techniques and from different sources which varied in scale and resolution. This was done to illustrate the versatility of the program and its application to a wide range of data types. On the whole, the results obtained using the GEOSTRUC© analyses compare favourably to field data from each test area. Use of the method to determine the orientation of axial planes in the case study revealed the usefulness of the method as a powerful analytic tool for use on a macroscopic scale. The method should not he applied in area with low variation in relief as the method proved to be less accurate in these areas. Advancements in imaging technology will serve to create images with better resolution, which will, in turn, improve the overall accuracy of the method.
- Full Text:
- Date Issued: 1996
- Authors: Slabber, Frans Bresler
- Date: 1996
- Subjects: Image processing , Geographic information systems , Information storage and retrieval systems -- Geology , Geology -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5001 , http://hdl.handle.net/10962/d1005614 , Image processing , Geographic information systems , Information storage and retrieval systems -- Geology , Geology -- Data processing
- Description: A computer-based method for determining the orientation of planar geological structures from remotely sensed images, utilizing digital geological images and digital elevation models (DEMs), is developed and assessed. The method relies on operator skill and experience to recognize geological structure traces on images, and then employs software routines (GEOSTRUC©) to calculate the orientation of selected structures. The operator selects three points on the trace of a planar geological feature as seen on a digital geological image that is co registered with a DEM of the same area. The orientation of the plane that contains the three points is determined using vector algebra equations. The program generates an ASCII data file which contains the orientation data as well as the geographical location of the measurements. This ASCII file can then be utilized in further analysis of the orientation data. The software development kit (SDK) for TNTmips v5.00, from MicroImages Inc. and operating in the X Windows environment, was employed to construct the software. The Watcom C\C++ Development Environment was used to generate the executable program, GEOSTRUC© . GEOSTRUC© was tested in two case studies. The case studies utilized digital data derived from the use of different techniques and from different sources which varied in scale and resolution. This was done to illustrate the versatility of the program and its application to a wide range of data types. On the whole, the results obtained using the GEOSTRUC© analyses compare favourably to field data from each test area. Use of the method to determine the orientation of axial planes in the case study revealed the usefulness of the method as a powerful analytic tool for use on a macroscopic scale. The method should not he applied in area with low variation in relief as the method proved to be less accurate in these areas. Advancements in imaging technology will serve to create images with better resolution, which will, in turn, improve the overall accuracy of the method.
- Full Text:
- Date Issued: 1996
Methods for assessing the susceptibility of freshwater ecosystems in Southern Africa to invasion by alien aquatic animals
- Authors: De Moor, Irene J
- Date: 1994
- Subjects: Biotic communities -- South Africa , Animal introduction , Freshwater ecology -- Africa, Southern , Animal introduction -- South Africa , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5300 , http://hdl.handle.net/10962/d1005145
- Description: Two methods for predicting regions susceptible to invasion by alien aquatic animals were developed for southern Africa (excluding Zimbabwe and Mozambique). In the "traditional" (data-poor) approach, distributions of three categories of alien "indicator" species (warm mesothermal, cold stenothermal and eurytopic) were compared to seven existing biogeographical models of distribution patterns of various animals in southern Africa. On the basis of these comparisons a synthesis model was developed which divided southern Africa into seven regions characterised by their susceptibility to invasion by alien aquatic animals with particular habitat requirements. In the "data-rich," geographic information systems (GIS) approach, the distribution of trout (Oncorhynchus mykiss and Salmo trutta) in selected "sampled regions" was related to elevation (as a surrogate of water temperature) and median annual rainfall (MAR) (as a surrogate of water availability). Using concentration analysis, optimum conditions for trout were identified. Regions within a larger "predictive area" which satisfied these conditions, were plotted as a digital map using the IDRISI package. Using this method seven models of potential trout distribution were generated for the following regions: northern Natal (two); southern Natal/Lesotho/Transkei (three), eastern Cape (two) and western Cape (two). Since two of the models were used to refine the methods, only five models were considered for the final assessment. In a modification of the GIS method, another model of potential trout distribution, based on mean monthly July minimum air temperature and MAR parameters, was developed for the region bounded by 29º - 34º S and 26 º - 32°E. This model showed marked similarities to another model, developed for the region bounded by 29 º - 32°S and 26º - 32°E, which was based on elevation and MAR parameters. The validity of the models developed was assessed by independent experts. Of the six models considered, four received favourable judgements, one was equivocal and one was judged to be poor. Based on these assessments it was concluded that the GIS method has credibility and could be used to develop a "data-rich" model of the susceptibility of southern Africa to invasion by alien aquatic animals. This method represents an alternative to the bioclimatic matching approach developed by scientists in Australia. The GIS method has a number of advantages over the "traditional" method: it is more amenable to testing, has greater flexibility, stores more information, produces images of a finer resolution, and can be easily updated. The traditional method has the advantage of being less expensive and requiring a less extensive database.
- Full Text:
- Date Issued: 1994
- Authors: De Moor, Irene J
- Date: 1994
- Subjects: Biotic communities -- South Africa , Animal introduction , Freshwater ecology -- Africa, Southern , Animal introduction -- South Africa , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5300 , http://hdl.handle.net/10962/d1005145
- Description: Two methods for predicting regions susceptible to invasion by alien aquatic animals were developed for southern Africa (excluding Zimbabwe and Mozambique). In the "traditional" (data-poor) approach, distributions of three categories of alien "indicator" species (warm mesothermal, cold stenothermal and eurytopic) were compared to seven existing biogeographical models of distribution patterns of various animals in southern Africa. On the basis of these comparisons a synthesis model was developed which divided southern Africa into seven regions characterised by their susceptibility to invasion by alien aquatic animals with particular habitat requirements. In the "data-rich," geographic information systems (GIS) approach, the distribution of trout (Oncorhynchus mykiss and Salmo trutta) in selected "sampled regions" was related to elevation (as a surrogate of water temperature) and median annual rainfall (MAR) (as a surrogate of water availability). Using concentration analysis, optimum conditions for trout were identified. Regions within a larger "predictive area" which satisfied these conditions, were plotted as a digital map using the IDRISI package. Using this method seven models of potential trout distribution were generated for the following regions: northern Natal (two); southern Natal/Lesotho/Transkei (three), eastern Cape (two) and western Cape (two). Since two of the models were used to refine the methods, only five models were considered for the final assessment. In a modification of the GIS method, another model of potential trout distribution, based on mean monthly July minimum air temperature and MAR parameters, was developed for the region bounded by 29º - 34º S and 26 º - 32°E. This model showed marked similarities to another model, developed for the region bounded by 29 º - 32°S and 26º - 32°E, which was based on elevation and MAR parameters. The validity of the models developed was assessed by independent experts. Of the six models considered, four received favourable judgements, one was equivocal and one was judged to be poor. Based on these assessments it was concluded that the GIS method has credibility and could be used to develop a "data-rich" model of the susceptibility of southern Africa to invasion by alien aquatic animals. This method represents an alternative to the bioclimatic matching approach developed by scientists in Australia. The GIS method has a number of advantages over the "traditional" method: it is more amenable to testing, has greater flexibility, stores more information, produces images of a finer resolution, and can be easily updated. The traditional method has the advantage of being less expensive and requiring a less extensive database.
- Full Text:
- Date Issued: 1994
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