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Groundwater-vegetation interactions in rangeland ecosystems : a review
(MDPI, 2025-04) Rapiya, Monde; Ramoelo, Abel
Water scarcity is a growing global issue, especially in arid and semi-arid rangelands, primarily due to climate change and population growth. Groundwater is a crucial resource for vegetation in these ecosystems, yet its role in supporting plant life is often not fully understood. This review explores the interactions between groundwater and vegetation dynamics in various rangeland types. Groundwater serves as a critical water source that helps sustain plants, but changes in its availability, depth, and quality can significantly impact plant health, biodiversity, and ecosystem stability. Research indicates that groundwater depth affects vegetation types and their distribution, with specific plants thriving at certain groundwater levels. For instance, in grasslands, shallow groundwater can support diverse herbaceous species, while deeper conditions may favor drought-tolerant shrubs and trees. Similarly, in forest ecosystems, extensive root systems access both groundwater and soil moisture, playing a vital role in water regulation. Savanna environments showcase complex interactions, where trees and grasses compete for water, with groundwater potentially benefiting trees during dry seasons. Climate change poses additional challenges by altering rainfall patterns and temperatures, affecting groundwater recharge and availability. As a result, it is crucial to develop effective management strategies that integrate groundwater conservation with vegetation health. Innovative monitoring techniques, including remote sensing, can provide valuable information about groundwater levels and their impact on vegetation, enhancing water resource management. This review emphasizes the importance of understanding groundwater–vegetation interactions to guide sustainable land and water management practices. By enhancing our knowledge of these connections and utilizing advanced technologies, we can promote ecosystem resilience, secure water resources, and support biodiversity in rangeland systems. Collaborative efforts among local communities, scientists, and policymakers are essential to address the pressing issues of water scarcity and to ensure the sustainability of vital ecosystems for future generations.
Mitigation of opportunistic pathogens in hot water systems : a review focused on premise plumbing in South Africa
(Water Research Commission, 2025-05) Moodley, S.J.; Venter, S.N. (Stephanus Nicolaas); Muchesa, P.; Barnard, T.G.; Singh, A.
Water reticulation systems (i.e., premise plumbing) serve as a reservoir for opportunistic premise plumbing pathogens (OPPPs) to survive within these premise systems. OPPPs can be transmitted to individuals mainly via inhalation of aerosols from these water systems. These OPPPs can adapt, thrive and survive under a range of different conditions, which include high temperatures and low oxygen levels during stagnation, conditions often associated with household plumbing systems, including hot water systems (HWS). Hospitals are of specific concern as infections caused by OPPPs predominantly affect individuals who have underlying illnesses or health conditions. The current South African National Standard (SANS) 241 for drinking water does not provide information regarding testing for the presence of OPPPs, while the SANS 893 and 893-1 standards only provide a guideline for Legionella in water systems. The presence of OPPPs within HWS and premise plumbing is a concern, and a need exists to establish remediation and mitigation measures to control the presence of OPPPs in buildings. This review addresses risk analysis, evaluation and measures, which include the control of geyser temperatures and training of plumbers, as well as sampling and detection of OPPPs. This should limit the number of infections amongst individuals and will thus lessen the financial burden on health care systems and the economy.
Quantifying urban land cover imperviousness as input for flood simulation using machine learning : South African case study
(IWA Publishing, 2025-05) Loots, Ione; Smithers, Jeffrey Colin; Kjeldsen, Thomas Rodding; ione.loots@up.ac.za
The imperviousness of urban surfaces is an important parameter in simulating urban hydrological responses, but quantifying imperviousness can be challenging and time-consuming. In response, this study presents a new framework to efficiently estimate the imperviousness of urban surfaces, using satellite images with Red, Green and Blue bands and a land cover dataset with multiple built-up urban classes through remote sensing, machine learning and field verification. The methodology is adaptable to other regions with similar datasets. For a case study in Pretoria, South Africa, major differences in median total impervious area percentages (mTIA%) were identified when compared between land cover groups: residential areas had a lower imperviousness median (mTIA% = 38%) than commercial (mTIA% = 81%) and industrial (mTIA% = 89%) land cover. The mTIA% also varies between 17 and 61% for a range of different formally developed residential classes and between 14 and 43% for a range of different informally developed residential classes. These mTIA% are recommended for any urban area within the South African National Land Cover dataset. These values can be incorporated into hydraulic and hydrological models, which improve the efficiency of parameter estimation for modelling. The methodology successfully quantified temporal imperviousness changes in the study area.
Delta ferrite in modified 9Cr–1Mo steel weld metal
(Springer, 2025) Mahlalela, Sibusiso Samuel; Pistorius, Pieter Georg Hendrik; sibusiso.mahlalela@up.ac.za
Please read abstract in the article.
Prevalence of lower back pain and associated workplace and ergonomic factors among mineworkers in a nickel mine, Zimbabwe
(MDPI, 2024-09-16) Zenda, Kumbirai P.; Rathebe, Phoka C.; Moto, Tshepo Paulsen; Masekameni, Daniel M.; Mbonane, Thokozani P.
Lower back pain is a common occurrence among mine workers due to the nature of their work. Globally, workplace (occupational) and ergonomic risk factors have been reported to influence the prevalence of lower back pain among workers. This study aimed to determine ergonomic risk factors associated with lower back pain and associated risk factors (workplace and ergonomics) among mineworkers in a nickel mine in Zimbabwe. A cross-sectional study design was employed, and participants were randomly selected to complete a questionnaire that included the Dutch Musculoskeletal Questionnaire (DMQ). A total of 420 mine workers were interviewed, with the majority being male (n = 259, 61.7%) and aged between 31 and 44 years old (n = 159, 37.9%). The study found that the prevalence of lower back pain was 41.43% (n = 174). Several risk factors were found to be associated with lower back pain, including working overtime (AOR = 1.13, p < 0.01; 95% CI: 0.07–0.22), performing repetitive tasks (AOR = 8.06, p < 0.01; 95% CI: 4.67–13.93), bending (AOR = 7.77, p < 0.01; 95% CI: 3.97–15.22), and twisting (AOR = 3.32, p < 0.01; 95% CI: 1.83–6.03). Based on these findings, it is recommended that an ergonomic risk assessment and prevention program be implemented, which should include educational awareness about lower back pain and its prevention among mine workers.