Land use/cover change modelling and land degradation assessment in the Keiskamma catchment using remote sensing and GIS
- Authors: Mhangara, Paidamwoyo
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10647 , http://hdl.handle.net/10948/1467 , Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Description: Land degradation in most communal parts of the Keiskamma catchment has reached alarming proportions. The Keiskamma catchment is particularly predisposed to severe land degradation associated with soil erosion, thicket degradation and deteriorating riparian vegetation. There is a close coupling between land use/cover dynamics and degradation trends witnessed in the catchment. Soil erosion is prevalent in most of the communal areas in the catchment. The principal aim of this study was to investigate land use/cover trends, model the spatial patterns of soil loss and predict future land use/cover scenarios as a means of assessing land degradation in the Keiskamma catchment. Multi-temporal Landsat satellite imagery from 1972 to 2006 was used for land use/cover change analyses using object-oriented post-classification comparison. Fragmentation analysis was performed by computing and analyzing landscape metrics in the riparian and adjacent hillslope areas to determine the land cover structural changes that have occurred since 1972. The landscape function analysis was used to validate the current rangeland conditions in the communal areas and the former commercial farms. The current condition of the riparian zones and proximal hillslopes was assessed using the Rapid Appraisal of Riparian Condition and future land use/cover scenarios were simulated using the Markovcellular automata model. Spatial patterns of soil loss in the Keiskamma catchment were determined using the Sediment Assessment Tool for Effective Erosion Control (SATEEC), which is a GIS based RUSLE model that integrates sediment delivery ratios. Object oriented classification was used to map soil erosion surfaces and valley infill in ephemeral stream channels as a means of demonstrating the major sediment transfer processes operating in the Keiskamma catchment. The Mahalanobis distance method was used to compute the topographic thresholds for gully erosion. To understand the effect of soil characteristics in severe forms of erosion, laboratory analyses were undertaken to determine the physico-chemical soil properties. iv The temporal land use/cover analysis done using the post-classification change detection indicated that intact vegetation has undergone a significant decline from 1972 to 2006. The temporal changes within the intermediate years are characterized by cyclic transitions of decline and recovery of intact vegetation. An overall decline in intact vegetation cover, an increase in degraded vegetation and bare eroded soil was noted. Fragmentation analyses done in the communal villages of the central Keiskamma catchment indicated increasing vegetation fragmentation manifested by an increase in smaller and less connected vegetation patches, and a subsequent increase of bare and degraded soil patches which are much bigger and more connected. The Landscape Organisation Index revealed very low vegetation connectivity in the communal rangelands that have weak local traditional institutions. Fragmentation analyses in the riparian and proximal hillslopes revealed evidence of increasing vegetation fragmentation from 1972 to 2006. The Markov Cellular Automata simulation predicted a decline in intact vegetation and an increase in bare and degraded soil in 2019. The Keiskamma catchment was noted as experiencing high rates of soil loss that are above provincial and national averages. The classification of erosion features and valley infill showcased the vegetation enrichment in the ephemeral streams which is occurring at the expense of high soil losses from severe gully erosion on the hillslopes. This in turn has led to an inversion of grazing patterns within the catchment, such that grazing is now concentrated within the ephemeral stream channels. Soil chemical analyses revealed a high sodium content and low soluble salt concentration, which promote soil dispersion, piping and gully erosion. The presence of high amounts of illite-smectite in the catchment also accounts for the highly dispersive nature of the soil even at low SAR values. Significant amounts of swelling 2:1 silicate clays such as smectites cause cracking and contribute to the development of piping and gullying in the catchment. Given the worsening degradation trends in the communal areas, a systematic re-allocation of state land in sections of the catchment that belonged to the former commercial farms is recommended to alleviate anthropogenic pressure. Strengthening local institutions that effectively monitor and manage natural resources will be required in order to maintain v optimum flow regimes in rivers and curb thicket degradation. Measures to curb environmental degradation in the Keiskamma catchment should encompass suitable ecological interventions that are sensitive to the socio-economic challenges facing the people in communal areas.
- Full Text:
- Date Issued: 2011
- Authors: Mhangara, Paidamwoyo
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10647 , http://hdl.handle.net/10948/1467 , Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Description: Land degradation in most communal parts of the Keiskamma catchment has reached alarming proportions. The Keiskamma catchment is particularly predisposed to severe land degradation associated with soil erosion, thicket degradation and deteriorating riparian vegetation. There is a close coupling between land use/cover dynamics and degradation trends witnessed in the catchment. Soil erosion is prevalent in most of the communal areas in the catchment. The principal aim of this study was to investigate land use/cover trends, model the spatial patterns of soil loss and predict future land use/cover scenarios as a means of assessing land degradation in the Keiskamma catchment. Multi-temporal Landsat satellite imagery from 1972 to 2006 was used for land use/cover change analyses using object-oriented post-classification comparison. Fragmentation analysis was performed by computing and analyzing landscape metrics in the riparian and adjacent hillslope areas to determine the land cover structural changes that have occurred since 1972. The landscape function analysis was used to validate the current rangeland conditions in the communal areas and the former commercial farms. The current condition of the riparian zones and proximal hillslopes was assessed using the Rapid Appraisal of Riparian Condition and future land use/cover scenarios were simulated using the Markovcellular automata model. Spatial patterns of soil loss in the Keiskamma catchment were determined using the Sediment Assessment Tool for Effective Erosion Control (SATEEC), which is a GIS based RUSLE model that integrates sediment delivery ratios. Object oriented classification was used to map soil erosion surfaces and valley infill in ephemeral stream channels as a means of demonstrating the major sediment transfer processes operating in the Keiskamma catchment. The Mahalanobis distance method was used to compute the topographic thresholds for gully erosion. To understand the effect of soil characteristics in severe forms of erosion, laboratory analyses were undertaken to determine the physico-chemical soil properties. iv The temporal land use/cover analysis done using the post-classification change detection indicated that intact vegetation has undergone a significant decline from 1972 to 2006. The temporal changes within the intermediate years are characterized by cyclic transitions of decline and recovery of intact vegetation. An overall decline in intact vegetation cover, an increase in degraded vegetation and bare eroded soil was noted. Fragmentation analyses done in the communal villages of the central Keiskamma catchment indicated increasing vegetation fragmentation manifested by an increase in smaller and less connected vegetation patches, and a subsequent increase of bare and degraded soil patches which are much bigger and more connected. The Landscape Organisation Index revealed very low vegetation connectivity in the communal rangelands that have weak local traditional institutions. Fragmentation analyses in the riparian and proximal hillslopes revealed evidence of increasing vegetation fragmentation from 1972 to 2006. The Markov Cellular Automata simulation predicted a decline in intact vegetation and an increase in bare and degraded soil in 2019. The Keiskamma catchment was noted as experiencing high rates of soil loss that are above provincial and national averages. The classification of erosion features and valley infill showcased the vegetation enrichment in the ephemeral streams which is occurring at the expense of high soil losses from severe gully erosion on the hillslopes. This in turn has led to an inversion of grazing patterns within the catchment, such that grazing is now concentrated within the ephemeral stream channels. Soil chemical analyses revealed a high sodium content and low soluble salt concentration, which promote soil dispersion, piping and gully erosion. The presence of high amounts of illite-smectite in the catchment also accounts for the highly dispersive nature of the soil even at low SAR values. Significant amounts of swelling 2:1 silicate clays such as smectites cause cracking and contribute to the development of piping and gullying in the catchment. Given the worsening degradation trends in the communal areas, a systematic re-allocation of state land in sections of the catchment that belonged to the former commercial farms is recommended to alleviate anthropogenic pressure. Strengthening local institutions that effectively monitor and manage natural resources will be required in order to maintain v optimum flow regimes in rivers and curb thicket degradation. Measures to curb environmental degradation in the Keiskamma catchment should encompass suitable ecological interventions that are sensitive to the socio-economic challenges facing the people in communal areas.
- Full Text:
- Date Issued: 2011
Using social marketing to bridge the gap between systematic conservation planning and implementation at the local government level
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
An exploration into the challenges faced by rural communities in the effective use of land for subsistence agriculture for poverty alleviation: a case study of the Mpongo and Twecwana communities in the Eastern Cape
- Authors: Mlonyeni, Xolani
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Community Development)
- Identifier: vital:11844 , http://hdl.handle.net/10353/d1005645 , Land use -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape
- Description: The escalation of poverty simultaneously with the decline of small-scale agriculture in the rural areas of the Eastern Cape in particular, raises serious concerns within the government circles in South Africa and among researchers. Of the nine provinces of South Africa, the rate of poverty in the Eastern Cape is a pathetic one and is the largest contributor to poverty statistics in the whole of South Africa. Machete (2004) stresses that high levels of poverty are visible in the rural areas and the large proportions of the people who are poor in South Africa are found in the rural areas. It is widely accepted that small-scale agriculture plays a vital role in and contributes substantially to socio-economic life of people living in the rural areas and is one of the strategies most suited to combat poverty for the majority of the people in the rural areas. This study explored the challenges that limit the effective use of land for subsistence agriculture as a strategy for poverty alleviation at Mpongo and Twecwana villages in Tsholomnqa. The study adopted a qualitative approach in order to get in-depth understanding of the challenges as experienced by the participants. The sample comprised of fifteen (15) subsistence farmers and three (3) extension officers from the department of agriculture. The data was collected from the participants through the focus group technique with an interview schedule containing open ended questions. The findings of the study indicated that the communities lack capital such as money, machinery, labour and other resources needed to pursue agricultural livelihoods. The findings also showed that agricultural infrastructure such as dams, rivers, fencing have deteriorated. Machete (2004, p.8) concurring with Pote (2008) says “inadequate physical infrastructure in the rural areas, particular in the former homeland areas remains a major obstacle to smallholder agricultural growth in South Africa”. In the two villages the situation is worsened by a total lack of irrigation scheme development. These communities rely entirely on seasonal and natural rainfall for their crops to be cultivated and grown. It was also found that the introduction of state grants contributed for the rural communities to do way with their traditional socio-economic agricultural livelihoods. The end results were for food production from gardens and communal fields come to a total collapse in many communities in the rural areas. The findings also show that youth is less interested to participate and pursue agricultural based activities in the rural areas. Williams et al (2008) claim that young people are unwilling to pursue agricultural studies as career of choice because of negative image attached to it. Many youths regard agriculture as an activity which belongs to adult and ordinary people. Drought was also cited as the worst natural disaster that has threatened the already disadvantaged small scale agriculture in these rural areas. These deficiencies have rendered subsistence agricultural centred activities to a total collapse.
- Full Text:
- Date Issued: 2011
- Authors: Mlonyeni, Xolani
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Community Development)
- Identifier: vital:11844 , http://hdl.handle.net/10353/d1005645 , Land use -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape
- Description: The escalation of poverty simultaneously with the decline of small-scale agriculture in the rural areas of the Eastern Cape in particular, raises serious concerns within the government circles in South Africa and among researchers. Of the nine provinces of South Africa, the rate of poverty in the Eastern Cape is a pathetic one and is the largest contributor to poverty statistics in the whole of South Africa. Machete (2004) stresses that high levels of poverty are visible in the rural areas and the large proportions of the people who are poor in South Africa are found in the rural areas. It is widely accepted that small-scale agriculture plays a vital role in and contributes substantially to socio-economic life of people living in the rural areas and is one of the strategies most suited to combat poverty for the majority of the people in the rural areas. This study explored the challenges that limit the effective use of land for subsistence agriculture as a strategy for poverty alleviation at Mpongo and Twecwana villages in Tsholomnqa. The study adopted a qualitative approach in order to get in-depth understanding of the challenges as experienced by the participants. The sample comprised of fifteen (15) subsistence farmers and three (3) extension officers from the department of agriculture. The data was collected from the participants through the focus group technique with an interview schedule containing open ended questions. The findings of the study indicated that the communities lack capital such as money, machinery, labour and other resources needed to pursue agricultural livelihoods. The findings also showed that agricultural infrastructure such as dams, rivers, fencing have deteriorated. Machete (2004, p.8) concurring with Pote (2008) says “inadequate physical infrastructure in the rural areas, particular in the former homeland areas remains a major obstacle to smallholder agricultural growth in South Africa”. In the two villages the situation is worsened by a total lack of irrigation scheme development. These communities rely entirely on seasonal and natural rainfall for their crops to be cultivated and grown. It was also found that the introduction of state grants contributed for the rural communities to do way with their traditional socio-economic agricultural livelihoods. The end results were for food production from gardens and communal fields come to a total collapse in many communities in the rural areas. The findings also show that youth is less interested to participate and pursue agricultural based activities in the rural areas. Williams et al (2008) claim that young people are unwilling to pursue agricultural studies as career of choice because of negative image attached to it. Many youths regard agriculture as an activity which belongs to adult and ordinary people. Drought was also cited as the worst natural disaster that has threatened the already disadvantaged small scale agriculture in these rural areas. These deficiencies have rendered subsistence agricultural centred activities to a total collapse.
- Full Text:
- Date Issued: 2011
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