High-resolution hydraulic modelling as an approach to planning rehabilitation interventions in unchanneled valley-bottom palmiet wetlands: a case study of the Kromme River
- Authors: Langner, Wiebke
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424610 , vital:72168
- Description: This study employs high-resolution hydraulic modelling techniques to inform the planning of rehabilitation interventions in unchanneled valley-bottom palmiet wetlands, using the upper Kromme River wetlands as a case study. It investigates the impact of geomorphic processes on the morphology of the valley, how changes in valley morphology affect the flow characteristics (velocity, stream power, depth) of the river, and how these changes affect the geomorphic dynamics of the wetlands. An aerial LiDAR survey was conducted for a 23km-long reach of the upper Kromme River where the wetlands are situated. A high-resolution (5 m) DTM was created from the LiDAR data to examine the valley morphology. Focusing on three major wetland basins, the relationship between valley morphology and geomorphic processes was examined using high-resolution imagery that accompanied the LiDAR survey and Google Satellite imagery. The hydraulic modelling software HEC-RAS was used to investigate the spatial variation in velocity, stream power, and water depth down the surveyed length of the river. The model outputs provide insight into the effect of valley morphology on flow characteristics. The river appears to have a graded longitudinal profile, such that there is a systematic reduction in slope down its length. Water flowing down the river works, through the processes of erosion and deposition, to control the longitudinal slope, channel planform, and geometry to create a valley with a gentle longitudinal slope (approximately 1%) and a broad, near-horizontal valley-bottom in the mountainous landscape of the Cape Fold Mountains. The overall form of the Kromme River valley and wetlands is primarily a consequence of repeated cycles of cutting and filling. Tributary alluvial fans control the initiation of gully erosion in the wetlands, but their effect is diminished in a downstream direction. Despite a 10-fold increase in discharge down the 23km length of river for a given flood magnitude, there is no significant increase in flow velocity, stream power, or depth in a downstream direction. Consequently, the kinetic energy of the water in the lower wetland basin is surprisingly low. These conditions favour the establishment of palmiet. Flows in eroded reaches are much higher than in non-eroded reaches where discharge is spread across a broad valley bottom. In terms of palmiet establishment and regeneration, this means that areas dominated by depositional processes are best suited to the establishment of palmiet. Based on this information, optimal sites to trial new wetland rehabilitation strategies that employ palmiet were selected. This work supports the importance of understanding the role of geomorphology in wetland structure and dynamics when approaching wetland rehabilitation and is likely to be more sympathetic to natural processes than current interventions. , Thesis (MSc) -- Faculty of Science, Geography, 2023
- Full Text:
- Authors: Langner, Wiebke
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424610 , vital:72168
- Description: This study employs high-resolution hydraulic modelling techniques to inform the planning of rehabilitation interventions in unchanneled valley-bottom palmiet wetlands, using the upper Kromme River wetlands as a case study. It investigates the impact of geomorphic processes on the morphology of the valley, how changes in valley morphology affect the flow characteristics (velocity, stream power, depth) of the river, and how these changes affect the geomorphic dynamics of the wetlands. An aerial LiDAR survey was conducted for a 23km-long reach of the upper Kromme River where the wetlands are situated. A high-resolution (5 m) DTM was created from the LiDAR data to examine the valley morphology. Focusing on three major wetland basins, the relationship between valley morphology and geomorphic processes was examined using high-resolution imagery that accompanied the LiDAR survey and Google Satellite imagery. The hydraulic modelling software HEC-RAS was used to investigate the spatial variation in velocity, stream power, and water depth down the surveyed length of the river. The model outputs provide insight into the effect of valley morphology on flow characteristics. The river appears to have a graded longitudinal profile, such that there is a systematic reduction in slope down its length. Water flowing down the river works, through the processes of erosion and deposition, to control the longitudinal slope, channel planform, and geometry to create a valley with a gentle longitudinal slope (approximately 1%) and a broad, near-horizontal valley-bottom in the mountainous landscape of the Cape Fold Mountains. The overall form of the Kromme River valley and wetlands is primarily a consequence of repeated cycles of cutting and filling. Tributary alluvial fans control the initiation of gully erosion in the wetlands, but their effect is diminished in a downstream direction. Despite a 10-fold increase in discharge down the 23km length of river for a given flood magnitude, there is no significant increase in flow velocity, stream power, or depth in a downstream direction. Consequently, the kinetic energy of the water in the lower wetland basin is surprisingly low. These conditions favour the establishment of palmiet. Flows in eroded reaches are much higher than in non-eroded reaches where discharge is spread across a broad valley bottom. In terms of palmiet establishment and regeneration, this means that areas dominated by depositional processes are best suited to the establishment of palmiet. Based on this information, optimal sites to trial new wetland rehabilitation strategies that employ palmiet were selected. This work supports the importance of understanding the role of geomorphology in wetland structure and dynamics when approaching wetland rehabilitation and is likely to be more sympathetic to natural processes than current interventions. , Thesis (MSc) -- Faculty of Science, Geography, 2023
- Full Text:
The effectiveness of bank debt financing on the growth of small and medium enterprises (SMEs) in Namibia
- Paulus, Panduleni Hambeleleni
- Authors: Paulus, Panduleni Hambeleleni
- Date: 2023-10-13
- Subjects: Business enterprises Finance , Small business Namibia , Small and medium enterprises , Stakeholder management , Debt financing (Corporations)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419176 , vital:71622
- Description: Globally, SMEs are valued for their contribution to economic growth and development as well as for driving employment. To succeed, small firms require support especially in terms of obtaining funding and financial services that can enable them to meet day to day operational needs. Commercial banks play an important role for the financing of SMEs as small firms generally depend on bank loans to obtain external finance. However, despite the support and contribution, very little attention is given to the actual forms of finance used by small and medium-sized enterprises, the available finance made by lending institutions or investors and the relation between the use of the said debt finance and enterprise performance. Furthermore, several research studies carried out focusing on the effect of debt financing on performance of firms are inconsistent. Thus, this study sought to determine the effectiveness of bank debt finance on the growth of SMEs in Namibia. To achieve the objective of the study, it was important to have it rooted in the pragmatism paradigm; followed by both the deductive and inductive approaches. Interviews were conducted with the six SME owners and structured questionnaires were completed by the seven staff of the selected bank. The study used thematic analysis to analyze primary data from interviews by following three steps namely: reducing the data referred to as coding, analyzing data by creating patterns, and generating themes and drawing conclusion. Data from self-administered questionnaires was populated and textually analyzed aided by tables. The main findings of the study were that: (1) debt financing contributed to the growth and performance of SMEs as all firms under the study who made use of debt had experienced growth in terms of generated profits and acquired assets, (2) during the assessment and approving process, the bank looked at various lending factors and that collateral was not considered as prime to accessing funding, (3) the SMEs were not sufficiently funded and that there was no appropriate funding option for SMEs, (4) in terms of relationships, there was a lack of engagement and support between the bank and the SMEs. The support received from the bank was only in terms of lending. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Authors: Paulus, Panduleni Hambeleleni
- Date: 2023-10-13
- Subjects: Business enterprises Finance , Small business Namibia , Small and medium enterprises , Stakeholder management , Debt financing (Corporations)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419176 , vital:71622
- Description: Globally, SMEs are valued for their contribution to economic growth and development as well as for driving employment. To succeed, small firms require support especially in terms of obtaining funding and financial services that can enable them to meet day to day operational needs. Commercial banks play an important role for the financing of SMEs as small firms generally depend on bank loans to obtain external finance. However, despite the support and contribution, very little attention is given to the actual forms of finance used by small and medium-sized enterprises, the available finance made by lending institutions or investors and the relation between the use of the said debt finance and enterprise performance. Furthermore, several research studies carried out focusing on the effect of debt financing on performance of firms are inconsistent. Thus, this study sought to determine the effectiveness of bank debt finance on the growth of SMEs in Namibia. To achieve the objective of the study, it was important to have it rooted in the pragmatism paradigm; followed by both the deductive and inductive approaches. Interviews were conducted with the six SME owners and structured questionnaires were completed by the seven staff of the selected bank. The study used thematic analysis to analyze primary data from interviews by following three steps namely: reducing the data referred to as coding, analyzing data by creating patterns, and generating themes and drawing conclusion. Data from self-administered questionnaires was populated and textually analyzed aided by tables. The main findings of the study were that: (1) debt financing contributed to the growth and performance of SMEs as all firms under the study who made use of debt had experienced growth in terms of generated profits and acquired assets, (2) during the assessment and approving process, the bank looked at various lending factors and that collateral was not considered as prime to accessing funding, (3) the SMEs were not sufficiently funded and that there was no appropriate funding option for SMEs, (4) in terms of relationships, there was a lack of engagement and support between the bank and the SMEs. The support received from the bank was only in terms of lending. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
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