Magister Scientiae - MSc (Environ & Water Science)

Permanent URI for this collection

https://hdl.handle.net/10566/17575

Browse

Now showing 1 - 20 of 60

Investigation of the carbon storage potential of the Sundays River Trough in the Algoa Basin
(University of the Western Cape, 2023) Moleele, Tshiamo; opuari, Mimonitu
Algoa Basin, South Africa, was extensively studied using data from three selected wells: AL 1/69, CK 1/68, and NA 3/70. These wells were chosen due to their positioning within tThe storage potential for carbon dioxide (CO2) within the Sundays River Trough, located in the he Sundays River The storage potential for carbon dioxide (CO2) within the Sundays River Trough, located in the Algoa Basin, South Africa, was extensively studied using data from three selected wells: AL 1/69, CK 1/68, and NA 3/70. These wells were chosen due to their positioning within the Sundays River Trough and the availability of geophysical wireline logs, conventional core analysis, geological well completion reports, and 2D seismic lines. Physical rock properties, such as lithology and reservoir zones, were identified, and quantitative parameters like volume of clay, porosity, and water saturation were determined. Permeability was calculated using basic log functions. The storage potential of CO2 was assessed by employing CO2SCREEN, and the total estimated storage potential for the Sundays River Trough was obtained. The 'Geological Storage of Carbon Dioxide' Atlas, published by the Council of Geosciences, provides estimates of the potential CO2 storage capacity in geological formations across the entire country. Previous studies have focused on investigating CO2 storage in geological formations, particularly saline aquifers, at a regional scale, with a primary focus on the Zululand Basin region. This research aims to enhance the ongoing understanding of CO2 storage potential, enabling the development of pilot programs and subsequent injection initiatives. By doing so, South Africa can actively contribute to the reduction of carbon emissions and effectively mitigate climate change. The total expected storage potential in the Sundays River Trough, considering the three selected areas surrounding wells AL 1/69, CK 1/68, and NA 3/70, amounted to P10= 13.37Mt, P50= 54.22Mt, and P90= 160.26Mt in the Sundays River formation and P10= 12.52Mt, P50= 50.45Mt, and P90= 147.97Mt in the Wood Beds formation withWell CK 1/68 exhibiting no storage potential, Based on the acceptable storage estimates of the Sundays River & Wood Beds formation and factoring in Smith et al. (2011) site screening criteria, the Sundays River Trough does have potential for CO2 storage. However, it leans towards negative site screening criteria due to low permeability and low porosity. The presence of old 2D seismic lines also plays a major role in determining that the Sundays River Trough may not be entirely suitable for storage.
An assessment of wetland vulnerability to artisanal mining in Zimbabwe
(Universty of the Western Cape, 2024) Dube, Thandekile; Dube, Timothy
The preservation of wetlands and pristine riverine eco-hydrological systems in sub-Saharan Africa, is crucial for biodiversity, ecosystem stability, and water availability. These face escalating threats from factors such as rapid population growth, agricultural expansion, and, more importantly, emerging illegal artisanal mining. To address these challenges, this study comprehensively evaluates the impact of artisanal mining on wetland ecosystems in Zimbabwe and proposes possible management strategies for mitigating environmental degradation. To achieve this goal, the research begins with a comprehensive literature review focused on the impact of artisanal mining on wetlands in semi-arid environments of sub-Saharan Africa. The findings underscore the detrimental effects of artisanal mining on wetland ecosystems, including habitat loss, biodiversity decline, riverbed sedimentation, and heavy metal pollution. Subsequently, the study investigated in the Umzingwane Catchment, located in southern Zimbabwe as a case study, to analyse variations in water nutrient and metal concentrations in wetlands affected by illegal mining activities along riparian zones (wetland-dominated areas).
Quantifying the consumptive water use of Japanese plum orchards in the Western Cape province using the SEBS and SEBAL models
(Universty of the Western Cape, 2024) Motsei, Nonofo; Jovanović, Nebojša
Japanese plums form part of a multi-billion-rand deciduous fruit industry in South Africa. As with other dry countries, South Africa faces several water-related challenges, namely increasing water scarcity driven by a high population growth rate, rising intersectoral competition for water resources and climate change. Due to the low and erratic rainfall in the country, plums are grown under irrigation. As such the availability of water is crucial for the sustainability and growth of the South African fruit industry. Previous studies have successfully determined the water requirements of various fruit crops (e.g., apples, oranges), however, the water use requirements of plum orchards have not been sufficiently investigated. This paucity of knowledge forms the baseline of this study which aims to quantify the seasonal water use of high performing full-bearing Japanese plum orchards. To address this aim, the study was divided into two sections. In the first section, the water use of optimally irrigated, full bearing and high performing Japanese plum orchards planted to mid and late maturing Fortune and African Delight cultivars was estimated using the SEBS model and Fruit Look (SEBAL).
Environmental and socio-economic feasibility of solar powered groundwater pumps in drought affected areas of giyani Limpopo.
(University of the Western Cape, 2023) Mpambo, Mandelwa; Jovanovic, Nebojsa
In the South African context, large portions of rural population do not have access to water supply. Shallow groundwater in alluvial aquifers of ephemeral (or dry sand bed) rivers can potentially be an alternative sustainable source of water for multiple uses. Solar-powered groundwater pumps could be suitable to reduce abstraction costs in rural areas that are often far from national grid connections. The objectives of this study were to conduct an environmental and socio-economic feasibility assessment of using solar-powered groundwater pumps in rural villages of Greater Giyani Municipality (Limpopo). The environmental assessment dealt with environmental issues associated with the use of solar pumps by analysing their emission of CO2 as compared to alternative energy supply options such as fuel and electricity. The socio-economic aspects dealt with the capital and maintenance costs associated with the system as compared to alternative sources of energy. A cost-benefit analysis was conducted in order to determine financial benefits, returns on investment and payback periods of using solar powered groundwater pumps. A life cycle analysis of the solar powered system was conducted. The results indicated a great market strength exists for these solar powered systems and even though they have high initial costs, their running costs are lower compared to alternative sources (diesel and grid). The life cycle analysis done using OPENLCA software showed that solar powered water pumps have environmental impacts especially during their manufacturing phase.
Using stable isotopes and hydrochemistry to quantify end-member source dynamics in the Berg River of the Franschhoek and Paarl Valley
(University of the Western Cape, 2023) Meyer, Celine; Clarke, Sumaya
The Berg River is a main source of freshwater in South Africa's Franschhoek-Paarl valley for domestic use, industry, and agriculture, but climate change or variability and poor management threaten its quality and quantity. A theoretical understanding of the basin's runoff processes, including the balance between groundwater and precipitation inputs in the river system, is crucial for meeting ecological reserve requirements and preserving ecosystems. By comprehending the dynamics and relationship between the river and its end-member sources by evaluating the contributions of groundwater and precipitation to the streamflow and the seasonal behaviour of solutes, the ecological health and functioning of the river and its associated ecosystems can successfully be managed and maintained. This study involved 25 sampling campaigns conducted between 2020 and 2021 along the Berg River in the Franschhoek and Paarl valley at 40 locations to sample precipitation (n=3), groundwater (n=15), and main river and major tributaries (n=22). The aim was to assess the temporal and spatial variations of the isotopic and hydrochemical compositions to quantify the river’s end-member source dynamics.
Water use productivity of the rooibos tea crop in the winter rainfall region, Western Cape, South Africa
(University of the Western Cape, 2023) Mkhanzi, Wasanga; Mazvimavi, D
Aspalathus linearis, commonly known as rooibos or red tea, is one of the well-known herbal tea beverages in South Africa. A. linearis is known for its medicinal, economic, traditional and ecological values. This leguminous shrub is endemic to the greater Cederberg Region of the Western Cape Province, South Africa. The area receives winter rainfall. With the Western Cape Province predicted to get drier in future with increasing temperatures and heat waves, the sustainability of range restricted species like A. linearis may be negatively affected by climate change. Given the value of the rooibos crop, there is a need to establish the sustainability of rooibos production to mediate the effects of climate change. Henceforth, this study seeks to determine the water use and yield patterns of rain-fed rooibos crops. In addition, the study sought to test how environmental conditions affect rooibos production and estimate the water use efficiency of A. linearis under present-day (May 2019-June 2020) conditions in a prime rooibos growing area in Porterville in the Western Cape Province. The study's objectives were achieved by determining the micro-climate, soil physical properties, plant attributes and the water use dynamics of cultivated A.linearis. Weather data were obtained from an automatic weather station (AWS). The field leaf area index (LAI) was measured using a LAI-2000 leaf area meter. Plant growth was determined by measuring plant height, width and breath. Soil samples were collected to determine the type and physical properties of the soil at the rooibos field, while soil moisture content was determined in the field using soil moisture probes at 20, 40, 60, 80 and 100 cm depths. Water use of the rooibos crop was quantified using various methods such as micro-stem heat balance sap flow sensors, Penman Montheith equation, open path eddy covariance, FruitLook and the soil water balance method. Lastly, to assess the potential impact of climate change on the rooibos crop, ETo was estimated using two Shared Socioeconomic Pathways (SSPs): SSP1-2.6 and SSP5-8.5. The results show that the study area is dominated by sandy soils, characterised by a low water holding capacity. The rooibos crop's average growth ranged from 1.0 cm in winter to 12cm in spring. LAI increased steadily from 0.28 in June and reached its peak at 1.56 in December.
An assessment of river and wetland morphology dynamics using geospatial techniques
(University of the Western Cape, 2023) Mbambi, Yamkela; Dube, Timothy
Land surface modification has intensified in recent years, and it continues to be an ongoing process. This raises serious concerns about changes in land use and land cover (LULC) since some of these changes have led to catchment degradation. The degradation of catchments has been observed to have adverse effects on natural resources, such as water bodies, resulting in food insecurity, water scarcity, and the degradation of ecosystems and the environment. Therefore, to effectively sustain life and the environment, it is crucial to monitor LULC changes for sustainable development and planning that can help alleviate pressures on water resources. This study aims to assess the impacts of LULC changes on the morphology dynamics and area changes of water resources in the Heuningnes catchment in South Africa. The findings from this assessment can offer valuable insights for water resource conservation in this catchment. Remote sensing and GIS techniques were employed to map and detect LULC changes, morphology dynamics, and area changes of water resources from 1990 to 2020.
An assessment of factors influencing the spatial variability of iron concentrations in groundwater in selected areas of the Western Cape Province.
(University of the Western Cape, 2023) Bissonram, Presanta; Clarke, Sumaya
Groundwater in South Africa, and more specifically the Western Cape Province (WCP), has become of major interest in recent years due to the unpredictable climatic conditions and the uncertainty of surface water to continuously meet the current and future water demands. With the exploration of groundwater (through the drilling of boreholes) to meet the current water demand and to ensure water security there comes the related problem of iron (Fe) and Manganese (Mn) oxidation and precipitation. The precipitation of Fe and Mn in boreholes reduce the yield and quality of the water, resulting in borehole clogging. This study took place in the WCP and the sites sampled at were hospitals as part of the business continuity project that was initiated during the drought in that took place in Cape Town in 2017. There are 4 objectives for this study which are to assess spatial variations in Fe and Mn concentrations, to establish site-specific processes controlling the concentration of Fe and Mn in groundwater, to model the likelihood of precipitation of Fe and Mn based on detected solution composition and to assess the best practice method/techniques for sampling Fe and Mn. This research project made use of quantitative and qualitative research methods. The first two objectives was addressed by using historical data which included groundwater chemistry data, pumping test data and geological data of the WCP. In addition to the historical data being used sampling was done at selected sites to understand the current groundwater chemistry, while interviews were conducted with site maintenance personnel to further understand the management of the boreholes. The third objective made use of the PHREEQC software to determine the saturation indices of samples collected and modelling of the effect of change in Fe, Mn, redox potential, pH and temperature has on the precipitation of Fe and Mn minerals. The last objective was achieved through the sampling conducted which provided the opportunity to test the best practice sampling methods of Fe and Mn in groundwater.
A lab based experimental study of a bioretention system to remove selected pharmaceuticals in stormwater
(University of the Western Cape, 2023) Maphiri, Refiloe; Clarke, Sumaya
The use of treated stormwater as an alternative source of water supply in urban areas is receiving global recognition. This approach is being supported as an innovative initiative that improves urban water security and diversifies urban water demand management options. However, reported toxic pollutants from some land-use activities threaten the quality of stormwater thereby restricting the potential for using stormwater to augment the water supply system. Such reported risks entail the treatment of the stormwater before its use for any purpose. Therefore, this study reports the findings of the research which investigated the effectiveness of a bioretention system in removing pharmaceuticals from stormwater and the influence of retention time and stormwater volumes on the removal efficiency of the pharmaceuticals by the bioretention system. To achieve the objectives of the study, there was a need to identify and measure the concentration levels of the pharmaceuticals found in stormwater. It was also necessary to determine the removal efficiency of the identified pharmaceuticals by using the Turf Grass and Pennisetum plants in a bioretention system with soil media control.
The fate and occurrence of pharmaceuticals in Cape Town’s water network
(University of the Western Cape, 2022) Cloete, Mikyle; Clarke, Sumaya
Thousands of pharmaceuticals, pesticides and microplastics are consumed and disposed of directly or indirectly into various water bodies globally. Which are collectively termed “contaminants of emerging concern” or CECs. Contaminants of emerging concerns are defined as micropollutants that are present in the environment that are not regulated and that can pose a risk to the health of both humans and wildlife. The distribution of these CECs in water systems is not isolated to a specific place and is on the rise all over the world. This study aims to investigate the spatial and temporal distribution of pharmaceuticals in the environment regarding the change in concentration along a flow path from potential sources to sink, to assess the occurrence, concentration levels and distribution of pharmaceuticals in various water bodies.
Use of remotely sensed data and spatial modelling techniques to assess impacts of different land management practices on surface water quality
(University of the Western Cape, 2023) Cloete, Danielle; Dube, Timothy
The study uses remote sensing and statistical techniques in assessing land use land cover impacts on surface water quality in the Heuningnes Catchment, Cape Agulhas, South Africa. Firstly, a review of the advancements made in extracting water quality information because of land use land cover impacts, specifically the advancements of modelling techniques that consider spatiotemporal variations across water quality parameters was conducted. The review results show that advancements made across small-scale waterbodies and developing countries such as sub-Saharan Africa are impaired by resource and data constraints
Assessing the surface water - groundwater interaction and its influence on the water quality from headwaters to lowlands
(University of the Western Cape, 2023) Cornelius, Aneeqah; Clarke, S
The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental in effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilized. Groundwater-surface water interactions are difficult to observe, measure, and have commonly been ignored in water management considerations and policies. Thus, it is important to understand the interaction between the two water bodies as it can have significant impacts on both water quantity and quality. The current study assessed groundwater – surface water interaction in order to understand how the interaction influences the available water resource in the Nuwejaars Catchment
The presence and concentration of antiretroviral drugs in different water bodies around the Western Cape
(University of the Western Cape, 2023) Maphumulo, Phumelele; Clarke, Sumaya
Concerns regarding the prevalence of chemicals from medicines and personal care goods, such as cosmetics, in streams and rivers have grown in recent years. Water quality experts and environmentalists are becoming increasingly worried about contaminants found in prescription and over-the-counter pharmaceuticals that enter various water systems. Pharmaceuticals are significant contributors to water pollution in aquatic habitats such as surface and groundwater. These contaminants are produced not only by waste materials, but also by improperly disposed of pharmaceutical items. South Africa has the world's highest rate of HIV (Human immunodeficiency virus infection) and AIDS (Acquired immune deficiency syndrome), with 8.2 million South Africans infected with HIV/AIDS, and 68% are receiving antiretroviral therapy. These medications get deposited in the environment and might reach water bodies, contaminating them.
Assessing hydrogeology of springs in Heuningnes Catchment in South Africa
(University of the Western Cape, 2022) Finini, Paula; Kanyerere, Thokozani
Springs have been a significant source of water for flora and fauna since the beginning of human history and, in some circumstances, the only source capable of supplying enough water to sustain domestic and agricultural water supplies. Research that expands our understanding of the potential and limitations of these resources has not focused much on springs that are located outside of karst environments. Groundwater discharge is part of the interaction that makes groundwater visible and sustains ecosystems. Groundwater discharges in rivers, springs, and wetlands forms groundwater-dependent ecosystems (GDEs). GDEs are often complex, and poorly understood component of the natural environment.
Assessment of groundwater level fluctuation trends in Grootfontein dolomite Aquifer, North West Province, South Africa
(University of the Western Cape, 2022) Rananga, Thomas Hulisani; Kanyerere, Thokozani
Groundwater level decline is a problem experienced in aquifers with more than one groundwater user such as the Grootfontein dolomite aquifer in the North West Province of South Africa. This study assessed groundwater level fluctuation trends for monitoring boreholes within municipal and irrigation groundwater abstraction areas. The study also determined the influence of rainfall and municipal groundwater abstraction as the dominant factors responsible for groundwater level fluctuation in the area. The study further recommended possible interventions for declining groundwater levels within the Grootfontein dolomite aquifer study area. Analysis of groundwater level fluctuation trend was conducted from 1980 to 2020 using Mann-Kendall and Sen's slope statistical tests. The results showed that groundwater levels in the study area had a declining trend. Spearman rank correlation was used to determine the influence of rainfall and municipal groundwater abstraction on groundwater level fluctuation within the study area.
Assessing hydrogeology of springs in Heuningnes Catchment in South Africa
(University of the Western Cape, 2021) Finini, Paula; Kanyerere, Thokozani
Springs have been a significant source of water for flora and fauna since the beginning of human history and, in some circumstances, the only source capable of supplying enough water to sustain domestic and agricultural water supplies. Research that expands our understanding of the potential and limitations of these resources has not focused much on springs that are located outside of karst environments. Groundwater discharge is part of the interaction that makes groundwater visible and sustains ecosystems. Groundwater discharges in rivers, springs, and wetlands forms groundwater-dependent ecosystems (GDEs). GDEs are often complex, and poorly understood component of the natural environment. For example, identifying actual spots for spring discharges and validating previously mapped springs remains a challenge; hence, the focus of the current study, which, argues that if spring hydrogeology is not characterized first, then the influence of such springs on the environment and human needs cannot inform their action. This study aimed at providing improved knowledge and understanding of spring hydrogeology. Heuningnes catchment in South Africa was used as a case study. Three specific objectives were set as follows: 1] spring hydrogeology was characterized where new springs were identified, and old springs were validated/crosschecked. A springs map was produced and overlaid on a conceptual model of groundwater flow to describe subsurface conditions for spring occurrence; 2] Flow dynamics of springs were determined where spring flows were measured to estimate discharge rate; 3] the hydrogeochemistry of springs was assessed with hydrogeochemical processes responsible for temporal and spatial changes in the quality of spring waters were established for suitability of water for use by the environment and people. Results showed that the validated springs existed in upland, middle, and lowland within the study catchment. Most springs were associated with Table Mountain Group and Bokkeveld formations with fractures, lithological contacts, and faults that influenced the main flow paths for springs.
Assessing effectiveness of groundwater remediation technologies to a coastal aquifer within an urban environment in South Africa
(University of the Western Cape, 2022) Kanyerere, Jessie Mzati; Clarke, Sumaya
The study aimed to assess the effectiveness of Reverse Osmosis technology as an example of ex-situ groundwater remediation technologies. The Cape Flats Aquifer System, an urban coastal system, was used as a case study. Globally, urban groundwater contamination remains a known problem for water users, hence the need to remediate such water. The study argues that effective technologies such as Reverse Osmosis to remediate groundwater contaminants exist. However, the effectiveness of such technologies is not demonstrated to inform the wider application. The question of how effective these technologies are in remediating groundwater contaminants is not fully understood.
Determining the efficiency of in situ iron remediation (ISIR) technology using ozonation in the Atlantis primary aquifer, Western Cape, South Africa
(University of the Western Cape, 2022) Rehman, Mushirah; Israel, Sumaya
In situ iron remediation (ISIR) applications has become a popular technique for reducing iron and manganese concentrations in boreholes that impose aesthetic and potable issues to groundwater quality and water supply schemes. Production borehole yields are reduced by screens clogged with iron and manganese precipitates, which jeopardizes groundwater extraction volumes and affect the supply of groundwater from supply schemes. Repeated ironand manganese-related borehole clogging in primary and fractured rock aquifers is a wellknown phenomenon in South Africa’s potable groundwater supply schemes.
Investigating the natural groundwater recharge and discharge processes of the Saldanha Bay aquifer systems along the West Coast of South Africa
(University of the Western Cape, 2022) Parker, Aqeela; Nel, Jaco
Saldanha Bay Local Municipality is partially dependent on groundwater as part of its bulk water supply as surface water resources in the area are extremely limited and fully allocated. Due to this, there is lots of pressure on the groundwater resources by industrial development and residential growth. Despite studies being conducted on these aquifer systems since 1976, they are still poorly understood, especially with regard to their recharge and discharge processes. This study aimed at providing better insight and understanding of the natural groundwater recharge and discharge processes to assist in the better management of groundwater resources in the Saldanha Bay Local Municipality area.
Assessing river-aquifer interaction for sustained water abstraction, Lower Vaal Catchment, South Africa
(University of the Western Cape, 2022) Baloyi, Lucky; Kanyerere, Thokozani
Several methods are available in the literature for the estimations of river-aquifer interactions. However, the selection of which depends on available data, local geographic and topographic conditions, the spatial and temporal scale required, and the reliability of results obtained by different methods. This study was caried out to assess the river-aquifer interaction for sustained water abstraction using the Lower Vaal River catchment as an example. The study aimed to improve knowledge and understanding of using multi-methods for the assessment of river-aquifer interactions. To achieve this, the study had three objectives namely, 1.) to investigate areas where river recharge aquifers exist (focussed recharge area), 2.) to determine areas where aquifer recharge river exist (aquifer discharge areas), and 3.) to develop a conceptual model of the groundwater process that explains interactions.

Browse

collection.page.browse.recent.head