Assessment of Pitman Model Capabilities in Modelling Surface Water-Groundwater Interactions in the Lake Sibaya Catchment, South Africa
- Authors: Ramatsabana, Phatsimo Pearl
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424188 , vital:72131
- Description: Difficulties arising from data scarcity, input data error or uncertainty, heterogeneous environments, lack of process understanding, and model structural uncertainty frequently constrain hydrological assessments of South African catchments. This research aimed to assess the usefulness of a “simpler” conceptual model for the conjunctive management of surface water and groundwater. The idea is that, to leverage the limited available data and information, a compromise between model complexity and data availability is required, which improves the use of models to produce reliable hydrological systems assessments. The research methodology focused on catchment-scale lake-groundwater dynamics to explore the limits of the groundwater components of the modified Pitman model (Hughes, 2004) in this type of environment, thus, determining the potential for using this model for integrated water assessments in South Africa. The Pitman model (Pitman, 1973; Hughes, 2013) is one of the most widely accepted models regarding surface water hydrology in South Africa; however, the newly incorporated groundwater components (Hughes, 2004) have not been applied as extensively as the surface water components. There remains uncertainty regarding their capability to adequately simulate groundwater processes and accurately represent surface and groundwater interactions in some environments. The model was assessed based on how well simulated water balance variables accurately reflected available evidence and expected catchment response (objective 1). Secondly, the research identified and addressed uncertainties as regards the structure and application of the model’s groundwater interaction components (objective 2). The model was set up for the Lake Sibaya catchment, which is a predominantly groundwater-driven system and, thus, provides an important opportunity to interrogate different aspects of uncertainty in both the conceptualizing and quantifying interaction processes. The study’s overall conclusion is that the model performed satisfactorily as it was able to simulate the lake’s water balance correctly enough such that the influences of dominating components were sensibly reflected in variations in streamflow and lake volumes. The following key findings were noted; (i) the lake volume shows a continuous decline, (ii) the lake volume decreased with increasing development (forestry and abstractions) in the lake catchment, (iii) there is significant rainfall uncertainty in the study area and the model showed high sensitivity to rainfall differences, (iv) robust conceptual knowledge of local catchment conditions was valuable for reducing some of the data related uncertainty in the study area and for producing realistic model simulations, (v) the Pitman model (Hughes, 2013) updated GW components can provide a valuable tool for modelling integrated hydrological processes; nevertheless, when applying the model to specific environments, implicit approaches may be necessary to account for processes that are not fully represented in the model. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
- Authors: Ramatsabana, Phatsimo Pearl
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424188 , vital:72131
- Description: Difficulties arising from data scarcity, input data error or uncertainty, heterogeneous environments, lack of process understanding, and model structural uncertainty frequently constrain hydrological assessments of South African catchments. This research aimed to assess the usefulness of a “simpler” conceptual model for the conjunctive management of surface water and groundwater. The idea is that, to leverage the limited available data and information, a compromise between model complexity and data availability is required, which improves the use of models to produce reliable hydrological systems assessments. The research methodology focused on catchment-scale lake-groundwater dynamics to explore the limits of the groundwater components of the modified Pitman model (Hughes, 2004) in this type of environment, thus, determining the potential for using this model for integrated water assessments in South Africa. The Pitman model (Pitman, 1973; Hughes, 2013) is one of the most widely accepted models regarding surface water hydrology in South Africa; however, the newly incorporated groundwater components (Hughes, 2004) have not been applied as extensively as the surface water components. There remains uncertainty regarding their capability to adequately simulate groundwater processes and accurately represent surface and groundwater interactions in some environments. The model was assessed based on how well simulated water balance variables accurately reflected available evidence and expected catchment response (objective 1). Secondly, the research identified and addressed uncertainties as regards the structure and application of the model’s groundwater interaction components (objective 2). The model was set up for the Lake Sibaya catchment, which is a predominantly groundwater-driven system and, thus, provides an important opportunity to interrogate different aspects of uncertainty in both the conceptualizing and quantifying interaction processes. The study’s overall conclusion is that the model performed satisfactorily as it was able to simulate the lake’s water balance correctly enough such that the influences of dominating components were sensibly reflected in variations in streamflow and lake volumes. The following key findings were noted; (i) the lake volume shows a continuous decline, (ii) the lake volume decreased with increasing development (forestry and abstractions) in the lake catchment, (iii) there is significant rainfall uncertainty in the study area and the model showed high sensitivity to rainfall differences, (iv) robust conceptual knowledge of local catchment conditions was valuable for reducing some of the data related uncertainty in the study area and for producing realistic model simulations, (v) the Pitman model (Hughes, 2013) updated GW components can provide a valuable tool for modelling integrated hydrological processes; nevertheless, when applying the model to specific environments, implicit approaches may be necessary to account for processes that are not fully represented in the model. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
Just stories?: Epistemic (in)justice and everyday resistance in the digital stories of family literacy practices by Grade 1-5 workers at a South African University
- Authors: Viedge, Jane Margaret
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/432308 , vital:72860
- Description: This thesis sets out to establish in what ways digital storytelling (DST) revealed instances of epistemic (in)justices inherent in the family literacy intervention experiences of four Black, working-class parents employed at a South African University1. Additionally, it explores how DST might be used by the participants (self-labelled the Storytelling Family Literacy - SFL Advocates) to correct any harm done. The context for the research is based on the deep-rooted harms of Bantu education in which Black South Africans were denied equal access to resources such as literacy practices. I investigated these aims by using the theories of DST, Communication for Social Change (C4SC) and epistemic (in)justice. As a participatory media practice supporting communications in marginalised communities, DST’s broad purpose is to assist these communities in telling stories of their lived experiences in ways that change dominant and, therefore, unchallenged views about them (Servaes & Malikhao 2014). In facilitating DST workshops with the SFL Advocates, I searched for evidence of epistemic (in)justice to enhance our (all stakeholders) understanding of their literacy experiences in ways that addressed their credibility status as ‘knowers’ (Fricker, 2007). Viewed through this lens, utilising DST provided a mechanism for understanding the impact of social interventions in a university setting that aimed to correct past injustices. The process involved online and face-to-face workshops with the participants during the Covid-19 Lockdown. The online format hampered data collection processes, and I resorted to face-to-face interactions for the workshops and interviews. These interactions were distinctly different from those I had experienced with participants in previous workshops, and they became a key focus in my analysis. Using narrative inquiry with critical realist and interpretive analysis techniques to interrogate the data, I discovered DST has both weaknesses and strengths as a C4SC communication tool. My findings revealed participants who, in the moment of leading their children and communities through the family literacy intervention, could claim to have redressed epistemic harms from the legacy of Apartheid education. However, by reflecting on this moment, the participants brought to light an epistemic harm that had been previously left unspoken: their sense of restored credibility as knowledge-bearers during the intervention was deeply shaken when the programme ended because they felt abandoned by the university. Therefore, the epistemic (in)justice lens unveiled hidden injustices that curtailed the participants’ ability to participate fully in the DST workshops. They described suffering the effects of pernicious and arbitrary acts of epistemic injustice at the hands of the University. Their participation in my workshops was erratic, and their stories were incomplete. As a result, I experienced difficulty analysing what I perceived as a lack of data. Moreover, despite my independent researcher status, my positionality as participant-observer was problematic as the participants may have perceived me as representative of the University and its institutional power. I responded to the problematic data by including a new theoretical framework in my analysis: the theory of everyday resistance (Vinthagen & Johansson, 2013). Combined with epistemic (in)justice theory and Vivienne’s ideas of using DST for everyday activism, I theorised how the participants negotiated their expressions of identity in epistemically unjust spaces. To put institutional epistemic injustice in perspective in the context of the University, I drew on Fricker’s three models of epistemic justice that enable fair and free conditions for marginalised workers to communicate for social change. , Thesis (MA) -- Faculty of Humanities, Journalism and Media Studies, 2023
- Full Text:
- Authors: Viedge, Jane Margaret
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/432308 , vital:72860
- Description: This thesis sets out to establish in what ways digital storytelling (DST) revealed instances of epistemic (in)justices inherent in the family literacy intervention experiences of four Black, working-class parents employed at a South African University1. Additionally, it explores how DST might be used by the participants (self-labelled the Storytelling Family Literacy - SFL Advocates) to correct any harm done. The context for the research is based on the deep-rooted harms of Bantu education in which Black South Africans were denied equal access to resources such as literacy practices. I investigated these aims by using the theories of DST, Communication for Social Change (C4SC) and epistemic (in)justice. As a participatory media practice supporting communications in marginalised communities, DST’s broad purpose is to assist these communities in telling stories of their lived experiences in ways that change dominant and, therefore, unchallenged views about them (Servaes & Malikhao 2014). In facilitating DST workshops with the SFL Advocates, I searched for evidence of epistemic (in)justice to enhance our (all stakeholders) understanding of their literacy experiences in ways that addressed their credibility status as ‘knowers’ (Fricker, 2007). Viewed through this lens, utilising DST provided a mechanism for understanding the impact of social interventions in a university setting that aimed to correct past injustices. The process involved online and face-to-face workshops with the participants during the Covid-19 Lockdown. The online format hampered data collection processes, and I resorted to face-to-face interactions for the workshops and interviews. These interactions were distinctly different from those I had experienced with participants in previous workshops, and they became a key focus in my analysis. Using narrative inquiry with critical realist and interpretive analysis techniques to interrogate the data, I discovered DST has both weaknesses and strengths as a C4SC communication tool. My findings revealed participants who, in the moment of leading their children and communities through the family literacy intervention, could claim to have redressed epistemic harms from the legacy of Apartheid education. However, by reflecting on this moment, the participants brought to light an epistemic harm that had been previously left unspoken: their sense of restored credibility as knowledge-bearers during the intervention was deeply shaken when the programme ended because they felt abandoned by the university. Therefore, the epistemic (in)justice lens unveiled hidden injustices that curtailed the participants’ ability to participate fully in the DST workshops. They described suffering the effects of pernicious and arbitrary acts of epistemic injustice at the hands of the University. Their participation in my workshops was erratic, and their stories were incomplete. As a result, I experienced difficulty analysing what I perceived as a lack of data. Moreover, despite my independent researcher status, my positionality as participant-observer was problematic as the participants may have perceived me as representative of the University and its institutional power. I responded to the problematic data by including a new theoretical framework in my analysis: the theory of everyday resistance (Vinthagen & Johansson, 2013). Combined with epistemic (in)justice theory and Vivienne’s ideas of using DST for everyday activism, I theorised how the participants negotiated their expressions of identity in epistemically unjust spaces. To put institutional epistemic injustice in perspective in the context of the University, I drew on Fricker’s three models of epistemic justice that enable fair and free conditions for marginalised workers to communicate for social change. , Thesis (MA) -- Faculty of Humanities, Journalism and Media Studies, 2023
- Full Text:
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