Book Chapters

Permanent URI for this collection

http://hdl.handle.net/10204/11484

Browse

Now showing 1 - 20 of 39

5.9 - Modelling estuaries in data-poor environments
(Elsevier, 2024-03) Scharler, UM; Gerber, G; Taljaard, Susan; Mackay, F
Models are inherently data-hungry for the construction, calibration, validation and predictive capacity that is demanded of models. In data-poor environments, a severe challenge to modelling is the lack of historic data, and present lack of sufficient monitoring programmes of important variables and number of estuarine ecosystems. This is largely due to lack of infrastructure, skills, political will, and monetary support. However, environmental challenges do not wait for adequate datasets to arrive to inform decision-making, and therefore different pathways to modelling that inform both research and management are needed. We present approaches to water quality, ecosystem modelling and climate change research in South African estuaries, as a representative of a data-poor environment. Such approaches aim to use available data in novel ways to inform research and decision-making, and identify data and information gaps. We propose that such methods be used in other data-poor areas with similar types of estuaries as South Africa and we provide recommendations how to construct, validate and use models and their outcomes. The communication of model uncertainty for research purposes and to decision-makers takes an important place in such endeavours.
Advancing mouth management practices in the Groot Brak Estuary, South Africa
(Delft Academic Press, 2020-02) Van Niekerk, Lara; Adams, JB; Taljaard, Susan; Huizinga, Piet; Lamberth, S; Slinger, J; Taljaard, Susan; D'Hont, F; Mittal, A
The early 1990s in South Africa were characterised by a strongly hierarchical and technocratic regime where planning and development decisions regarding the environment were made at national government level with little or no public consultation (Slinger et al., 2005). One such a decision was the construction of the 70 m high and 270 m wide Wolwedans Dam (with a capacity of 23 × 106 m3) only 3 km upstream of the Groot Brak Estuary (also known as the Great Brak Estuary) by the South African Department of Water Affairs and Forestry (DWAF) (Figure 6.1). However, then the local community of the Town of Groot Brak feared the effects of reduced water supply on the health of the estuary, as well as the risk of flooding during dam failure. Increasing public pressure, and consequent media coverage, culminated in the DWAF setting up a steering committee, the Groot Brak River Environmental Committee (GEC). This committee was tasked to investigate the effect of the dam on the estuary, and to establish a management plan for the optimal use of the reserved water (1 x 106 m3) to maintain current ecological health. The Council for Scientific and Industrial Research (CSIR) were commissioned to undertake this assessment (CSIR, 1990; Slinger et al., 2005).
Air quality and health
(Health Systems Trust, 2024-02) John, Juanette; Perumal, Sarisha; Mlambo, Mfundo; Naidoo, Mogesh; Ndlovu, Noluthando; Padarath, Ashnie
Exposure to polluted air causes millions of premature deaths each year and can lead to health risks such as reduced lung growth and function, respiratory infections and aggravated asthma. Many deaths related to air pollution occur in Asia and Africa and poor air quality places an additional burden on the health.
An alternative rainwater harvesting system design methodology
(Alive2green, 2020-12) Gibberd, Jeremy T; De Jager, Peta
Climate change and rapid urbanisation have meant there is increasing pressure on water supplies in human settlements in South Africa. This has led to unreliable water supplies and outages. It is therefore important to understand whether there are alternative sources of water which can be used to improve the resilience of supply. One solution is to develop onsite rainwater harvesting systems. These capture rainwater from roofs and other surfaces and store this. Stored water can then be used instead of municipal water supplies for drinking, cleaning, irrigation and flushing toilets. While these systems can be highly effective and significantly reduce mains water consumption, they are not widely used in South Africa. This situation has been compounded by a lack of guidance on the calculation and sizing of rainwater harvesting systems. To address this gap this study presents, and critically evaluates, an alternative rainwater harvesting design methodology based on the Rainwater Use Model (RUM). The RUM methodology is compared to conventional methodologies by applying this to a case study building to carry out rainwater harvesting calculations for a range of scenarios. These results suggest that the RUM methodology may be more accurate than conventional methods. By enabling different aspects of the systems to be tested rapidly, the RUM methodology also provides useful guidance on where investment should be focused in the design of a rainwater harvesting system. The study will be of interest to Architects, Engineers and Planners who need to develop more resilient and sustainable water resources in human settlements in dry areas.
Barriers to closing the loop on nutrient recycling - a case study on phycoremediation of domestic wastewater in South Africa
(Alive2Green, 2021-12) Steyn, Maronel; Oberholster, PJ; De Jager, Peta
Sustainable development and the global move towards a more circular use of resources, where waste is reduced and resources are recycled, have caused a paradigm shift within the scientific community with regards to wastewater solutions. Nutrient recovery from organic waste streams is high on the development agenda and extends beyond direct economic benefits, to health and environmental benefits. Phycoremediation provides an alternative low-cost green solution to nutrient recovery from wastewater streams in developing countries. The current study utilizes a specific consortium of microalgal species (Chlorella vulgaris and Chlorella protothecoides) isolated and cultured specifically for their combined nutrient (total nitrogen and total phosphorous) removal efficiencies from domestic wastewater. The treatment was implemented at Brandwacht WWTW, a micro size waste stabilisation pond system managed by Mossel Bay local municipality in the Western Cape Province of South Africa. Total nitrogen removal efficacy after treatment was 73.1%, while total phosphorous removal was 50%. Even though the microbiological indicator, E. coli, were reduced by over 5 logs and the indicator numbers were far below that of the South African effluent discharge standards, the COD and other physicochemical parameters exceeded the discharge standards. The microalgae biomass was harvested by means of flocculation using Zetag 7557 from a small pilot scale plant, but very low concentrations were harvested.
Chapter One - Introduction
(Elsevier, 2020-01) Coelho, ST; Bouille, DH; Mani, SK; Stafford, William HL; Coelho, ST; Pereira, SA; Bouille, DH; Mani, SK; Recalde, MY; Savino, AA; Stafford, William HL
The adequate collection and disposal of municipal solid waste (MSW) remain a challenge in developing countries as a direct consequence of inadequate practices, which in turn produce negative environmental and social impacts. In industrialized countries most MSW are collected, reused, recycled, and, before being disposed in landfills, are recovered through waste-to-energy (WtE) systems. However, in developing countries, WtE technologies still face several barriers, in all aspects, and the synergies of WtE and basic sanitation are not yet well seen. In this context, the main objective of this publication is to analyze the current situation of MSW collection and disposal, allowing the discussion of the perspectives of WtE in Latin America, Africa, and Asia.
The circular economy, human settlements and municipal government
(Alive2Green, 2024-01) Cooper, Antony K; Kruger, Tinus; Godfrey, Linda K; Napier, Mark; De Jager, Peta
The linear economy is where resources (including energy and space) move through the economy in one direction, from being harvested, collected or mined, through refining and processing to create products and services, to uses and consumption, until being discarded. This creates value only while available resources are entering at one end and the waste exiting at the other does not foul up anything, or even everything.This chapter considers the current resources within human settlements for circularity, the expected trends, the potential resource constraints for future growth of circularity, key economic and socio-economic gains and losses associated with the linear economy, and opportunities for the circular economy in human settlements.
Complex Coastal Systems: Transdisciplinary Learning on International Case Studies
(Delft Academic Press, 2020-02) Slinger, J; Taljaard, Susan; D'Hont, F
The transdisciplinary research synthesised in this book represents an endeavour by a group of coastal researchers and policy analysts to learn from a cross-comparison of seven international case studies on tidal inlet or estuary mouth management situations, located in South Africa, Sri Lanka, California, Suriname, Ireland and the Netherlands. The conceptual framing is provided by a focus on systems knowledge and its development and use within coastal management.This book is intended for: • Transdisciplinary scholars who are interested in interdisciplinary learning and knowledge exchange, • Policy analysts, environmental historians and coastal policy specialists who are interested in the role of science in the evolution of coastal policy and management, • Coastal scientists and engineers interested in the dynamics of tidal inlets and estuary mouths, • Coastal managers looking to learn about tidal inlet and mouth management practices • Educators focussed on interdisciplinary skills or interested in using the case studies in coastal, management and engineering classes or as the basis for problem structuring exercises by policy students, and • Students interested in coastal systems management and wanting to broaden their interdisciplinary competence. We trust that this endeavour will inspire others to undertake transdisciplinary learning and contribute to wise coastal research and practice.
The contribution of the WRC to estuarine research in support of effective policy development and resource
(Water Research Commission, 2021-01) Van Niekerk, Lara; Adams, J; Taljaard, Susan; Lamberth, S; Day, J; Day, B; Reizenberg, J
The Water Research Commission (WRC) has been a staunch and enduring funder of estuarine research in South Africa, with support ranging from identifying research gaps, to the development of dedicated research programs, student advancement, capacity building and funding the development of policy and management tools. In drafting this overview, we have largely project leaders and steering committee members of a number of WRC projects. We have supported our experiential knowledge through a literature review to ensure that key outcomes were captured. The intent here is not to reflect all contributions through the decades, but rather to identify seminal research outputs that have resulted in clear policy and management interventions, or key research ‘stepping stones’ in the generation of new insights and knowledge on estuaries. In particular, we focus on the research that built multi-disciplinary understanding on estuarine ecosystem function, development of environmental water requirement methods, science that has contributed to integrated estuarine management, developments in estuarine monitoring in support of policy and management, and estuarine resource use and quantification of benefits. Finally, we touch on restoration,an emerging field of research supported by the WRC, and conclude with ideas on the role of the WRC in advancing future research in support of the protection and management of our valuable estuarine resources.
Cradle-to-gate environmental life cycle assessment of limestone calcined clay cement (LC3)
(Alive2Green, 2024-01) Dumani, Nozonke; Mapiravana, Joseph; De Jager, Peta
The manufacturing of cement contributes to approximately 5-7% of global anthropogenic carbon dioxide emissions, necessitating the need for reducing the environmental impact. Limestone Calcined Clay Cement (LC3) has emerged as a promising alternative to ordinary Portland cement (OPC), leveraging widely available resources like clay, limestone and gypsum to partially replace the carbon intensive Portland clinker. One ton of Portland cement is associated with about one (1) ton of CO2 . This study aimed to assess and compare the CO2 emissions of theoretical binary and LC3 cement types against 100% Ordinary Portland Cement (OPC). Considered were: OPC with 30% calcined clay replacement, and LC3, composed of 50% clinker, 30% calcined clay, 15% limestone, and 5% gypsum.
Creating a set of high-resolution vulnerability indicators to support the disaster management response to the COVID-19 pandemic in South Africa
(CRC Press, 2021-06) Le Roux, Alize; Cooper, Antony K; Ludick, Chantel J; Arnold, Kathryn A; Mans, Gerbrand G; Rajabifard, A; Paez, D; Foliente, G
This chapter presents the "COVID-19 Vulnerability Dashboard" for South Africa, developed by the CSIR for the National Disaster Management Centre (NDMC). It maps vulnerability to COVID-19 for the whole of South Africa, down to the level of the 103 576 enumerator areas (EAs). The COVID-19 Vulnerability Dashboard aims at helping the NDMC, local authorities and other stakeholders with disaster risk reduction (DRR) and evidence based decision making. Several national government departments have used the Dashboard for planning support. South Africa has large populations around the country vulnerable to COVID-19 because of the triple challenges of poverty, inequality and employment, and the high levels of HIV/AIDS and tuberculosis; high potential for rapid spread because of many dense informal settlements; and limited health resources. The COVID-19 Vulnerability Dashboard draws on our expertise in spatial analysis and disaster risk reduction of human settlements, and our tools, data and expertise including the Green Book, also developed in partnership with the NDMC, to deal with the likely impacts of climate change. Using a multi-criteria analysis approach, we created a set of vulnerability indicators based on domain knowledge, which was peer-reviewed by expert groups. These are disseminated by dynamic spatial mapping through an interactive, online dashboard.
Defining the South African acute respiratory infectious disease season
(2023-01) Motlogeloa, O; Fitchett, JM; Sweijd, Neville A
The acute respiratory infectious disease season, or colloquially the “flu season”, is defined as the annually recurring period characterized by the prevalence of an outbreak of acute respiratory infectious diseases. It has been widely agreed that this season spans the winter period globally, but the precise timing or intensity of the season onset in South Africa is not well defined. This limits the efficacy of the public health sector to vaccinate for influenza timeously and for health facilities to synchronize efficiently for an increase in cases. This study explores the statistical intensity thresholds in defining this season to determine the start and finish date of the acute respiratory infectious disease season in South Africa. Two sets of data were utilized: public-sector hospitalization data that included laboratory-tested RSV and influenza cases and private-sector medical insurance claims under ICD 10 codes J111, J118, J110, and J00. Using the intensity threshold methodology proposed by the US CDC in 2017, various thresholds were tested for alignment with the nineteen-week flu season as proposed by the South African NICD. This resulted in varying thresholds for each province. The respiratory disease season commences in May and ends in September. These findings were seen in hospitalization cases and medical insurance claim cases, particularly with influenza-positive cases in Baragwanath hospital for the year 2019. These statistically determined intensity thresholds and timing of the acute respiratory infectious disease season allow for improved surveillance and preparedness among the public and private healthcare.
Designing school rainwater harvesting systems in water-scarce developing countries
(Routledge, 2024) Gibberd, Jeremy T; Adler, I; Adeyeye, K; Bello-Dambatta, A; Takacs, B
Many schools in water-scarce developing countries have insufficient and unreliable water supplies. This is being exacerbated by climate change and ageing and poorly maintained water infrastructure. A lack of clean water increases the risks of diarrhoeal disease and concerns about health can result in school closures, affecting education outcomes as valuable teaching and learning time is lost. In these situations, rainwater harvesting systems can provide an alternative, clean water supply that enables schools to continue to operate safely. However, there is limited research and guidance on school rainwater harvesting systems. In addition, there are also misconceptions about rainwater harvesting. These include that rainwater harvesting systems cannot provide sufficient water to meet needs, the water produced is dirty and the systems are unaffordable. This chapter addresses this context by showing how rainwater harvesting can provide sufficient and affordable water supplies to schools in water-scarce areas. It may be of interest to school governing bodies, teachers, design professionals and government officials who want to develop rainwater harvesting systems in schools.
Development of advanced Pd-Based electrocatalysts for high performing fuel cell system
(Springer Cham, 2024-05) Fuku, Xolile G; Mkhohlakali, Andile C; Maumau, Thandiwe R; Modibedi, Remegia M; Raju, K, K; Makgopa, K; Modibane, KD; Lichfouse, E
The globe is in increased need of non-fossil energy sources due to existing energy limits and global pollution issues. This chapter will discuss fuel cell energy systems as a cleaner and more environmentally friendly alternative energy source. Fuel cells have gotten a lot of press in the twenty-first century because of their potential as an alternate component of energy production. The present barrier of the fuel cell is the high cost of production materials and the manufacturing process itself. The chapter will focus on core practices that can help fuel cells compete with other energy production technologies by reducing costs and improving operational performance. This will entail providing insights into recent breakthroughs in energy materials, with a focus on new approaches or methods of synthesising materials such as platinum group metal and non-platinum group metal electrocatalysts. The electrochemical kinetic processes and catalytic activity of created catalysts, as well as the power outputs of the manufactured membrane electrode assembly in the desired Fuel cell systems, such as proton exchange membrane fuel cell (PEMFC) and Anion exchange membrane fuel cells (AEMFC), will be discussed in further detail in this chapter. Between the two systems, AEMFC is more advantageous over PEMFC because of the tolerance of non-platinum group metal catalysts thus becoming a preferred future system over PEMFC. Hence, AEMFC will be used as a preferred fuel cell system for our application.
Does non-motorised transport and EV culture reduce carbon footprint?
(Alive2Green, 2021-07) Sediki, Vhonani P
This review aims to answer the question whether Non-Motorised Transport and electric vehicle cultures help reduce carbon footprint related to commuting and whether the provision of infrastructure encourage the culture of walking, running, cycling and the adoption of electric vehicles. An investigation into the Effects of Non-Motorised Transport Facility Implementations and Upgrades in Urban South Africa was reviewed and revealed that South Africa is facing both safety and infrastructural challenges, which makes the NMT culture to be perceived as unattractive due to the lack of adequate and integrated infrastructure, with a fragmented network that is characterized by broken links or routes, therefore unable to meet the needs of users. The review was carried out in the South African context, evaluating the impact that the NMT infrastructure has had on trips generated due to upgraded pedestrian and cycling infrastructure. The impact of electric vehicle infrastructure was also reviewed and barriers to full adoption of the electric vehicle culture were addressed. Automotive marketplace, Autotrader’s survey on electric car buyer was reviewed to get an understanding of how well electric vehicles are being received in South Africa and what is hindering its success. A number of things came out which included the initial cost of purchase and the lack of charging infrastructure. The review went on to evaluate factors influencing the choice of the mode of travel and affordability, availability, distance and safety were on top of the list. This went on to show that the purpose of travel also influences the mode of travel. While other may perceive walking and cycling as just leisure activities, some are subject to those activities due to lack of monetary means to pay for public transport or even purchase a private car. The review also continued to evaluate some of the municipal interventions for working towards reducing carbon footprint related to commuting and aiming for net zero buildings in the year 2030. With the continuing trends and concerns about the impacts of climate change, it is crucial to develop ways to prevent air pollution and environmental degradation through sustainable and green practices. This paper reveals the need to encourage the transition to the Non-Motorised Transport (NMT) culture which allows people to walk, run and cycle, adopt electric vehicles (EV) over conventional vehicles, and introduce telecommuting policies in the workplace where the nature of business allows in order to reduce carbon footprint. It recommends how buildings should be designed to support the transportation sector to decarbonize commuting emissions and encourage the NMT culture. The uptake is however based on user experience and what is convenient to them. It was however revealed that a well-designed NMT infrastructure with inter-connected routes, connecting to social and economic activities may be able to address the needs of users. Successful adoption of electric vehicle is however a high-level issue which needs government intervention - introduction of incentives such as subsidies on the retail prices and import duties which seems to be the current and main barrier to a successful electric vehicle centric country.
Dual performance of fuel cells as efficient energy harvesting and storage systems
(Routledge: Taylor & Francis, 2021-11) Chinecherem, A; Kebede, Mesfin A; Ezema, Fabian I; Kebede, Mesfin A
The need for increased energy security in the nation has diverted energy sources from conventional forms to the use of fuel cells. Fuel cells are generally accepted for electricity generation due to their increased conversion efficiency, reliability, and compatibility with the environment. Fuel cell technology serves dual functions of energy harvesting and energy storage. Fuel cells convert chemical potential energy into electrical energy during the energy harvesting process while its energy is stored in molecular bonds. This chapter discusses the fuel cell system, their working principle, and dual performance of fuel cells for efficient energy harvesting and storage. These fuel cells exhibit advantages and disadvantages which have also been highlighted. The working principle, advantages, classifications, synthesis techniques, and potential applications of fuel cells will be discussed. Different classifications of fuel cells have been described and discussed alongside the methods of operations, merits, and demerits. The dual performance of fuel cells as energy harvesters and energy storage devices, their modes of operation, and useful application areas have been intensively discussed in this chapter.
Emerging adaptation constrains in Mount Darwin District, Zimbabwe
(Springer Nature, 2024-12) Chenzi, V; Mateyisi, Mohau J; Nangombe, SS; Maoela, MA
This chapter utilizes Mount Darwin district located in northern Zimbabwe’s Mashonaland Central province to examine climate change adaptation constrains in rural Southern Africa. The district is one of the worst affected regions by climate change in Zimbabwe. In order to shed greater light on climate change adaptation constrains in communal areas of Zimbabwe, the chapter canvassed a number of pertinent variables. These include, climate change-induced vulnerabilities, adaptation needs for catalytic economic sectors, livelihoods and food systems, adaptation responses and associated capital distribution in the context of the United Nations (UN) green development agenda, and domestication of adaptation solutions to meet Southern Africa’s needs. Findings from the study indicated that climate change vulnerabilities on rural livelihoods especially agriculture-based activities were influencing a shift towards artisanal mining as an alternative sustenance activity. Furthermore, there seems to be a symbiotic relationship between climate change patterns and livelihood activities in communal Zimbabwe. That is, climate change is not only influencing changes in rural livelihood activities, but the livelihood patterns are also responsible for intensifying the effects of climate change in the region. The study concluded by identifying several climate change adaptation measures in rural Southern Africa.
Emerging nanoelectrocatalysts for the oxidation of ethanol in alkaline fuel cells
(2024-05) Xaba, N; Fuku, Xolile; Maumau, Thandiwe; Modibedi, Remegia M; Khotseng, LE; Makgopa, K
The depletion of fossil fuel reserves accompanied by the overwhelming evidence of global warming has necessitated the shift from fossil-based fuels to environmentally friendly and sustainable energy sources. Fuel cells have received renewed interest in the energy sector due to their ability to provide clean energy and efficiency. Amongst other fuel cell types, direct alcohol fuel cells are popular for their potential application in portable electronics and electric vehicles. One of the major setbacks in the development of direct alcohol fuel cells is finding a suitable catalyst that effectively and cost-effectively converts the alcohol. Research efforts have been dedicated to finding suitable catalysts that are relatively cheap, efficient, and stable. This chapter reports on the emerging electrocatalysts for ethanol oxidation in alkaline media. The strategies used in producing different types of catalysts including the type of catalyst and support used to improve electrochemical activity towards electro-oxidation reaction are presented. It will also discuss in detail the electrochemical activity and membrane electrode assembly performance of selected catalysts.
Environmental challenges to meeting sustainable development goals in Southern Africa
(Springer, 2024-01) Mutanga, Shingirirai S; Skhosana, Felix; Mateyisi, Mohau; Thenga, Humbelani F; Naidoo, Sasha; Ramoelo, A; Nangombe, Shingirai S; Lumsden, Trevor G; Von Maltitz, GP; Midgley, GF; Veitch, J; Brümmer, C; Rötte, RP; Viehberg, FA; Veste, M
There is an inextricable link between ecosystem integrity and the potential for achieving sustainable development goals (SDG). This chapter highlights key ecosystem threats and their drivers within the southern African regional context to emphasize the role of earth system science in supporting the achievement of regional sustainable development goals. It describes how some major anthropogenic threats have unfolded in terrestrial, aquatic and marine ecosystems of the region. Earth system science is increasingly contributing to understanding how globally driven climate and environmental changes threaten these ecosystems, and in turn how these impact people’s livelihoods. Long-term changes in rainfall variability, concomitant disruption of hydrological balances, impacts on ocean chemistry, together with more immediate impacts on the frequency and magnitude of extreme climate events are some of the critical global change drivers. While terrestrial ecosystems are already faced with encroachment by novel species, characterized by the proliferation of both invasive alien and endemic woody species, freshwater and marine ecosystems appear more immediately threatened by more local impacts, such as the accumulation of contaminants. Overall, predicted climate and environmental changes are projected to hamper development trajectories and poverty reduction efforts, and possibly exacerbate adverse impacts on human livelihoods.
From waste to resource: Opportunities and challenges to combat water scarcity
(Alive2Green, 2022-09) Walters, Chavon R; Steyn, Maronel; De Jager, Peta
Many parts of South Africa are still staggering on the back of severe droughts experienced over the past decade. Rapid urbanization has created a plethora of water-related challenges, including environmental degradation and water scarcity accentuated by climate change. Under the IPCC emissions scenarios, these challenges are projected to further affect both atmospheric and hydrological circulations. The livelihoods and food security of rural communities of a predominantly urban population are therefore at risk from water-related impacts linked primarily to climate variability. In this context, unconventional water resources can play a critical role to achieve water security. Water scarcity, increased pollution, unprecedented population growth, and climate change are collectively driving the need to reuse water with the aim to enhance water security, sustainability, and resilience. It is clear that South Africa's already strained water resources will become even more stressed in the near future. The Department of Water and Sanitation predicted that by 2030 water demand will reach 17.7 billion m3, far more than what is available to allocate. Globally, responsible and efficient water management is fast becoming a pressing reality for domestic users, agriculture, and industry alike. The challenge is therefore to capitalize on the limited water we currently have. Several response strategies are available that will provide both near-term relief and long-term benefits. This chapter examines the significant potential contribution available from water reuse opportunities. Reuse constraints and future water management strategies are also addressed.

Browse

Browsing Book Chapters by browse.metadata.cluster "Smart Places"

Results Per Page

Sort Options