Research Articles (Geography, Geoinformatics and Meteorology)

Permanent URI for this collectionhttp://hdl.handle.net/2263/1936

A collection containing some of the full text peer-reviewed/ refereed articles published by researchers from the Department of Geography

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Foodification and neighbourhood change in Hazelwood, Pretoria
Barnes, Emily Sarah; Gregory, James Jenkins (Routledge, 2026)
This paper examines the phenomenon of foodification as a catalyst for consumption-driven urban transformation in Hazelwood, a suburban neighbourhood in Pretoria, South Africa. Hazelwood has undergone a visible shift from a quiet residential area to a vibrant culinary hub, reflecting broader global trends in urban change driven by food and consumption. This study explores how the proliferation of upscale restaurants and cafes has redefined Hazelwood’s spatial identity, creating a walkable, European-inspired enclave within a city dominated by shopping malls and chain eateries. The paper situates Hazelwood’s transformation within the context of post-apartheid urban dynamics, where neoliberal economic policies intersect with efforts to redress spatial injustices, resulting in complex patterns of social and economic change. Methodologically, this study employs content analysis, semi-structured interviews with key stakeholders and participant observation to capture the nuances of Hazelwood’s transformation. The findings highlight the cyclical relationship between consumption and the production of space, demonstrating how these processes drive rapid urban change and contribute to the commodification of urban neighbourhoods. Hazelwood’s evolution serves as a lens through which to explore the broader implications of consumption-driven urban change on social dynamics and spatial identity in South African cities.
Air quality in Africa from the telecoupled perspective : exploring interdisciplinary and transboundary scientific collaboration between Africa and the Global North
Dekker, Marleen; Kazimierczuk, Agnieszka H.; Garland, Rebecca M.; Stein-Zweers, Deborah; Levelt, Pieternel F. (Cambridge University Press, 2025-08)
NON-TECHNICAL SUMMARY : This article explores air pollution as a globally connected issue using the telecoupling lens, which links distant regions through environmental and human systems. It shows how pollution connects Africa and the Global North, demonstrating that actions in one place affect people and air quality elsewhere. Drawing on 90 research sources, it looks at how satellite data helps monitor air quality and finds that most studies focus on natural sciences, with limited input from social sciences and less frequently from African researchers. The authors highlight the need to close data gaps and call for more inclusive, cross-disciplinary, and international cooperation in air quality research. Overall, the study pushes for fairer, more connected approaches to understanding and tackling air pollution worldwide. TECHNICAL SUMMARY : Air quality (AQ) is a transboundary phenomenon resulting from globalized interactions between coupled human and natural systems. Drawing on the telecoupling framework, this article argues that pollution flows, socioeconomic systems, and policy responses interconnect Africa with the Global North and identifies important data gaps for better understanding these interconnections. Through a meta-synthesis of 90 academic and gray literature sources, we analyze the use of satellite data for air quality monitoring, with a particular focus on interdisciplinary collaboration and African scientific participation. Our findings highlight a strong reliance on natural science approaches, limited integration of social science perspectives, and ongoing marginalization of African voices in shaping research agendas. We argue for a transformative research agenda rooted in interdisciplinary integration, inter-regional collaboration, and data justice. By adopting a telecoupled lens and prioritizing inclusive development, this study provides new pathways to understand, measure, and address air pollution as a global issue with deeply local consequences. SOCIAL MEDIA SUMMARY : Air pollution links Africa & the Global North–study urges data justice & inclusive, global cooperation.
Sun protection advice for the South African population for the prevention and management of skin diseases
Isaacs, Thuraya; Jacobs, Tarryn; Whitaker, Dagmar; Visser, Willem; Wiid, Kim; Dlova, Ncoza C.; Wright, Caradee Yael; Tod, Bianca (Wiley, 2026-01)
Sun protection is critical for the prevention and management of skin cancer and other photosensitive dermatoses in South Africa's diverse population. This review expands on previously published sun protection advice for skin cancer prevention by providing tailored advice for individuals with specific dermatological conditions. Recent advances in sunscreen technology, including enhanced protection for long-wave UVA1, visible light, and infrared radiation; inorganic sunscreens with more cosmetic acceptability; and the addition of other active ingredients unrelated to sun protection, are discussed in the context of specific dermatoses. Visible light protection, particularly tinted sunscreens, is particularly relevant for dark to medium skin tones prone to pigmentary disorders, such as melasma and post-inflammatory pigmentation. Practical advice is provided for optimizing sun protection in inflammatory conditions, such as acne, rosacea, eczema, and psoriasis, where formulation and tolerability are important for compliance. Photoprotection for photo-dermatoses and human immunodeficiency virus (HIV)-associated dermatoses is also discussed. Recognizing the economic barriers to sunscreen access, the paper emphasizes the critical role of sun avoidance behaviors, such as sun-protective clothing and seeking shade, in resource-limited settings.
Evaluation of global remotely sensed evapotranspiration products in arid irrigated agricultural environments using ground measurements
Ratshiedana, Phathutshedzo Eugene; Abd Elbasit, Mohamed A. M.; Adam, Elhadi; Chirima, Johannes George (Taylor and Francis, 2025-12)
Accurate quantification of crop water requirement is essential for efficient irrigation practices. However, direct measurement of crop water use is localised and impractical over large areas. Remotely sensed evapotranspiration (ET) provides a solution by estimating spatial explicit ET. Nevertheless, the accuracy of ET products in South African irrigated agriculture remains uncertain. This study evaluated the accuracy of MODerate Resolution Imaging Spectroradiometer (MOD16), Noah Land Surface Model Evapotranspiration Product (NOAH) and Water Productivity Open-access Portal (WaPOR) products retrieved using Google Earth Engine (GEE). A stepwise validation approach was applied integrating lysimeter-derived actual evapotranspiration (ETa) with reference evapotranspiration (ETo) to extrapolate ETa across the Vaalharts irrigation scheme. Results demonstrated WaPOR as a promising product with correlations of 0.69 to 0.88, and lower errors with RMSE from 0.87 to 3.22 mm d−1, while MOD16 and NOAH estimates are poor. These findings demonstrate WaPOR as a potential tool for improving irrigation water management.
A fully satellite-driven workflow for hydrodynamic modeling in data-scarce coastal systems : integrating ICESat-2, Sentinel-2, SWOT and reanalysis model
Payandeh, Ali Reza; Simard, Marc; Jensen, Daniel; Campbell, Anthony Daniel; Van Deventer, Heidi; Christensen, Alexandra (Frontiers Media, 2026-03-11)
Hydrodynamic models in coastal and estuarine systems are typically constrained by sparse bathymetry, boundary, and validation data, especially in regions where field campaigns are costly or impractical. Here we develop and test a fully satellite-driven framework for hydrodynamic modeling in South Africa’s Langebaan Lagoon without using any local in situ measurements. Bathymetry is derived by training multispectral Sentinel-2 reflectance against ICESat-2 ATL24 photon-derived depths using an XGBoost model optimized with Bayesian search. The final satellite derived bathymetry reproduces independent ATL24 points with RMSE = 0.45 m and R2 = 0.97. This bathymetry was used in a depth-averaged Delft3D Flexible Mesh model driven at the open boundary by TPXO tidal harmonics and by ERA5 winds. We validate modeled water surface elevation against 16 SWOT low-rate (250 m, unsmoothed) passes in 2023. SWOT–model comparisons yield an overall RMSE of 0.11 m and R2 = 0.61, with typical point differences <0.10 m (∼5% of the 2 m tidal range), and showed consistent spatial gradients in water level from the offshore boundary, through Saldanha Bay, and into the lagoon. At the offshore boundary, TPXO and SWOT sea surface heights agree closely (R2 = 0.86). A ∼26 min phase lag, determined using a lag-correlation analysis, reduces the TPXO–SWOT RMSE from 0.18 m to 0.11 m, indicating that phase differences explain some of the mismatch, with remaining differences likely linked to non-tidal signals. Our results demonstrate that combining passive optical, photon-counting LiDAR, radar interferometry, and global tidal/atmospheric models enables robust, transferrable hydrodynamic modeling in data-scarce coastal systems, offering a cost-effective pathway for monitoring.
A warming climate may influence forecast performance : analysing the skill of maximum temperature seasonal climate forecasts over southern Africa
Ntele, Moahloli Phillip; Landman, Willem Adolf; Archer, Emma Rosa Mary (Wiley, 2026)
Understanding seasonal variability and development of skilful seasonal climate forecasts (SCFs) is key in mitigating climate-related risks, including helping to support adaptation to climate change and variability. The purpose of this study is to consider possible factors influencing the predictability of maximum temperature SCFs in southern Africa. To address this question, two hypotheses are tested: namely (1) There is skill in making maximum temperature forecasts in the Southern African Development Community (SADC); and (2) The skill is contributed by two main attributes—ENSO-related climate variability and anthropogenic climate change—as a result, temperature forecasts are worth taking into account in pre-season decision-making. A state-of-the-art global climate model's atmospheric thickness fields are statistically downscaled to maximum temperatures for the austral spring to autumn period. Forecast performance over a 24-year period is evaluated for both original and for linearly detrended temperature data. The verification results indicate that predictive skill for maximum temperatures reflects the combined influence of ENSO-related variability and long-term anthropogenic warming trends. The majority of the skill is not, however, a consequence of warming trends, since the climate model is able to predict the seasonal-to-interannual maximum temperatures variation skilfully, without assistance from temperature trends. Detrending data improves probabilistic skill, suggesting that removing trends helps isolate the seasonal signal, enhancing the models' reliability and discrimination of probabilistic maximum temperature SCFs. However, deterministic skill declines, revealing long-term climate trends' influence on the apparent accuracy of deterministic forecasts. The trend thus influences understanding of forecast performance and needs to be considered when conveying how good a forecasting system is.
Assessing farm-level sustainability : a comparative analysis of horticultural production systems in Eritrea
Haile, Bereket Tsehaye; Dougill, Andrew J.; Ramoelo, Abel; Kidane, Tesfai T. (Frontiers Media, 2025-07-02)
INTRODUCTION : Measuring the sustainability of agricultural practices at the farm level is a prerequisite for devising effective policies and strategies. This study offers an in-depth farm-level sustainability assessment of Eritrea’s horticultural sector. It aims to assess the sustainability of horticultural crop production using 12 customized indicators co-developed with local stakeholders, identify the principal factors influencing sustainability performance, and compare the sustainability performances across two regions of Eritrea with different agroecological and socioeconomic settings. METHODS : Primary data from 170 horticultural farmers were collected using a field survey focusing on activities conducted from 2020 to 2022. The assessment uses a traffic light approach to classify farms into three categories: unsustainable (red), acceptable (yellow), and sustainable (green). Multiple Linear Regression (MLR) is applied to explain the main factors contributing to the sustainability score of farms across the studied regions. RESULTS : The study shows disparities in sustainability performance between the two study regions as measured by the indicators. The MLR model shows that farming experience, extension services, and cooperative membership significantly influence most sustainability outcomes (p < 0.05). DISCUSSION : This study highlights the necessity for a context-specific approach to assess farm-level sustainability. By mapping the sustainability landscape of the horticultural sector and identifying key levers for improvement, the study paves the way for informed, impactful strategies to advance agricultural sustainability at the farm level.
Knowledge translation of climate change research into public health action
Mulopo , Chanelle; Onkoba, Nyamongo; Abimbola, Samuel; Baltaci, Ezgi; Wright, Caradee Yael; Schmidt, Bey-Marrie (Frontiers Media, 2025-10-27)
BACKGROUND : There are gaps in translating climate change research into public health action at the global level. Knowledge translation refers to the methods used to bridge the gap between knowledge and action. Given the significant impacts of climate change on health, it is essential to integrate climate research into health decision-making processes. This integration ensures that evidence effectively informs policies and practices at all levels, leading to more timely, equitable, and impactful public health responses. OBJECTIVE : This scoping review examines key approaches and identifies gaps in knowledge translation methods for integrating climate change research into public health decision-making. METHODS : A systematic search of the literature was conducted in PubMed, CINAHL, and Scopus using a predefined search string to identify studies on climate change and health published between January 1, 2003, and March 1, 2024, with no geographic restrictions. Retrieved articles were screened and data extracted using Covidence software. Thematic analysis was performed in ATLAS.TI employing Braun and Clark’s six-step method. The identified knowledge translation approaches were categorized according to the Cochrane Knowledge Translation Framework. FINDINGS : Our findings highlight five primary knowledge translation approaches: (1) monitoring the coverage of climate change and health across media, scientific literature, and government responses; (2) engaging citizens of all ages in participatory activities to address local climate challenges and co-develop policy solutions; (3) integrating knowledge generation, synthesis, and dissemination for effective communication; (4) emphasizing advocacy and education to foster collaborations and gain support from decision-makers; and (5) leveraging health impact assessment tools to guide decision-making related to climate change and health. Nonetheless, we did not find any primary studies on climate change research and knowledge translation in Low- and Middle-Income Countries (LMICs). CONCLUSION : There is a need for primary studies on the knowledge translation of climate change research, especially in relation to adaptation, into meaningful public health actions that can inform decision-making and contribute to building climate-resilient health systems in LMICs.
Temperature-related health impacts : a scoping review and benchmarking exercise to inform a heat action plan
Wright, Caradee Yael; Bulani, Muthise; Kapwata, Thandi; Dikoko, Viwe; Naidoo, Natasha (Ubiquity Press, 2026-01)
BACKGROUND : Global heating is associated with adverse health impacts necessitating the implementation of Heat Action Plans (HAPs) to protect communities. Gauteng in South Africa is the most populated province, housing three cities (i.e., Johannesburg, Ekurhuleni, and Pretoria) and 25% of the national population. OBJECTIVE : Given rising temperatures and projected increases in heatwaves and hot days, we gathered literature and case studies to inform the development of a Gauteng HAP. METHODS : We conducted a scoping review to inform baseline data on heat‑related health impacts for Gauteng and South Africa too, followed by a benchmarking exercise that aimed to identify international best practices that may inform Gauteng’s plan. Benchmarking was done using Maharashtra (India), Victoria (Australia), and Khyber Pakhtunkhwa (Pakistan). FINDINGS : Thirty‑six studies were included in the review, with 13 including Gauteng data and all showing impacts of heat on human health. Most studies applied epidemiological time series linking meteorological exposure (temperature/heat indices) and/or air pollutants (e.g., PM2.5, PM10, NO2, and O3) with health outcomes; applied remote‑sensing, reanalysis, or station data for exposure assessment; and used regression or distributed lag models. The benchmarking exercise identified exemplars’ distinctive strengths: Victoria’s district thresholds keep activation simple and local—ideal for Gauteng’s heterogeneous microclimates across metros and townships. Maharashtra’s graded activation and clear departmental roles reduce ambiguity during multi‑day heatwaves and thereby would help to align Gauteng Health, Infrastructure, Social Development departments. Khyber Pakhtunkhwa’s cooling‑camp model shows practical, low‑cost interventions of a low‑ and middle‑income country that can be replicated at taxi ranks/clinics/malls during temperature peaks. CONCLUSIONS : Insights from the literature and international exemplars provide a strong evidence base and adaptable models to guide a context‑specific, multi‑sectoral HAP for Gauteng that enhances preparedness, coordination, and community protection in a warming South Africa.
Spectral indices and principal component analysis for lithological mapping in the Erongo region, Namibia
Benade, Ryan Theodore; Ajayi, Oluibukun Gbenga (MDPI, 2025-12-18)
The mineral deposits in Namibia’s Erongo region are renowned and frequently associated with complex geological environments, including calcrete-hosted paleochannels and hydrothermal alteration zones. Mineral extraction is hindered by high operational costs, restricted accessibility and stringent environmental regulations. To address these challenges, this study proposes an integrated approach that combines satellite remote sensing and machine learning to map and identify mineralisation-indicative zones. Sentinel 2 Multispectral Instrument (MSI) and Landsat 8 Operational Land Imager (OLI) multispectral data were employed due to their global coverage, spectral fidelity and suitability for geological investigations. Normalized Difference Vegetation Index (NDVI) masking was applied to minimise vegetation interference. Spectral indices—the Clay Index, Carbonate Index, Iron Oxide Index and Ferrous Iron Index—were developed and enhanced using false-colour composites. Principal Component Analysis (PCA) was used to reduce redundancy and extract significant spectral patterns. Supervised classification was performed using Support Vector Machine (SVM), Random Forest (RF) and Maximum Likelihood Classification (MLC), with validation through confusion matrices and metrics such as Overall Accuracy, User’s Accuracy, Producer’s Accuracy and the Kappa coefficient. The results showed that RF achieved the highest accuracy on Landsat 8 and MLC outperformed others on Sentinel 2, while SVM showed balanced performance. Sentinel 2’s higher spatial resolution enabled improved delineation of alteration zones. This approach supports efficient and low-impact mineral prospecting in remote environments.
Moisture and dust in motion : the dual role of integrated vapour transport over West Africa
Awoleye, Peace O.; Adebiyi, Adeyemi A.; Abiodun, Babatunde J.; Balogun, Ifeoluwa A.; Akinbobola, Ademola; Oluleye, Ayodeji; Ajayi, Vincent O. (Springer, 2025-11)
Integrated vapour transports (IVTs) are important drivers of tropical moisture transport; however, their structure, seasonality, and meteorological impacts over West Africa remain poorly characterised. This study provides a comprehensive evaluation of detected IVTs using a transport threshold of ≥ 250 kg m− 1 s− 1 during the 2024 West African monsoon season, combining reanalysis and gridded in situ datasets. Results show a strong seasonal signal, with IVT frequency and intensity peaking between June and September, particularly over the Guinean and southern Sudano-Sahelian zones. Case studies of three extreme IVT (≥ 750 kg m− 1 s− 1) events (June 18, August 16, and September 25) revealed distinct structures, strong zonal wind cores at 700 hpa, and vertically coupled moisture fluxes that enhanced organised convection and upward motion. Moderate IVTs (250–500 kg m− 1 s− 1) contributed significantly to daily rainfall in coastal regions, while extreme transport (≥ 750 kg m− 1 s− 1) delivered intense, spatially focused precipitation in the Sahel. Also, the IVT played a critical role in the dynamics of atmospheric dust, where periods of extreme IVTs were associated with strong negative correlations with aerosol optical depth and dust concentrations, along with increased dust wet deposition. However, dust scavenging efficiency peaked beyond an IVT threshold of ~ 300 kg m− 1 s− 1, suggesting that rainfall variability, rather than moisture flux alone, contributes immensely to aerosol removal. These findings position IVTs as key synoptic-scale systems that shape West African rainfall patterns and aerosol dynamics, with implications for seasonal weather variability, air quality, and convective organisation across the monsoon belt. Within the West African Monsoon (WAM), IVTs preferentially align with the southern flank of the AEJ where horizontal moisture flux and shear-induced convergence maximise, while jet-level (150–200 hPa) wind maxima suggest TEJ-entrance ascent that deepens the moist column. The Saharan heat low’s seasonal migration sharpens meridional pressure gradients that precondition strong southwesterlies, favouring IVT initiation and inland penetration.
The environmental crisis : a religious solution?
Hugo, Leon; Hugo (Koers Society of South Africa, 2025-02-28)
The earth and its inhabitants are facing an impending environmental catastrophe. Despite remarkable technological advancements and sophisticated economic strategies, the situation continues to worsen at an alarming rate. The growing demand for higher living standards exacerbates the exploitation of resources, contributing to environmental degradation. Human greed and interpersonal competition drive the rapid extraction of natural resources, leading to the degradation of the planet's ecological foundation. Therefore, the solution does not lie in enhanced or restrained technological progress, educational programmes or new economic theories but in transforming human attitudes and aspirations, profoundly shaped by socio-economic and cultural-historical contexts. In this context, religion plays a crucial role in shaping individuals' worldviews. Most religious teachings advocate for the responsible use of resources, together with love and respect towards other human beings. If these core principles of environmental stewardship and care for others, along with the warnings against greed and the dangers of wealth, were more actively embraced, the current environmental crisis could have been avoided.
Lancet countdown on health and climate change in Africac: an international collaboration for locally led research and action
Ali, Zakari; Abubakar, Ibrahim; Amegah, Adeladza K.; Caussy, Deoraj; Cisse, Gueladio; Denton, Fatima; Esievo, Edith M.; Ihekweazu, Vivianne; Kaseya, Jean; Kimani-Murage, Elizabeth W.; Kone, Brama; Mabhaudhi, Tafadzwanashe; Makoni, Munyaradzi; Muchangi, Josphat Martin; Murray, Kris A.; Romanello, Marina; Sy, Ibrahima; Thiam, Sokhna; Walawender, Maria; Wright, Caradee Yael; Yaffa, Sidat; Zougmore, Robert B. (Elsevier, 2026-01)
Climate change inflicts substantial economic damage on developing African nations, threatening progress towards the UN Sustainable Development Goals. There are synergies between actions needed to tackle climate change and other ongoing development priorities for Africa, including infectious disease control, facilitating clean energy access, reducing air pollution, tackling malnutrition and food insecurity, and providing universal health coverage. Action to protect human health against climate change needs to be integrated into all systems that are responsible for delivering essential services and implementing policies across all sectors that underpin the attainment of key development priorities for Africa. These systems include the Sustainable Development Goals and the African Union's 2063 Agenda for building The Africa We Want, and the ongoing negotiations and work programmes in the UN Framework Convention on Climate Change. Adequate stocktaking of and access to robust data and scientific evidence is needed to support this effort and guide priorities for policies that protect and promote health and for monitoring progress over time. In response to this need, the Lancet Countdown is launching a new initiative to bring together a transdisciplinary research collaboration to help build regional capacity, strengthen existing networks, generate evidence, and mobilise data across numerous domains at the climate change and health nexus in Africa.
Towards a Global Ground-Based Earth Observatory (GGBEO) : leveraging existing systems and networks
Lappalainen, Hanna K.; Baklanov, Alexander; Bäck, Jaana; Arvanitidis, Christos; Basart, Sara; Bernier, Natacha; Berod, Dominique; Bornman, Thomas; Buttigieg, Pier Luigi; Carmichael, Gregory; Dañobeitia, Juanjo; De Roeck, Yann-Hervé; Dey, Sagnik; Gerasopoulos, Evangelos; Feig, Gregor Timothy; Gani, Shahzad; Glaves, Helen; Häme, Silja; Juurola, Eija; Klausen, Jörg; Laj, Paolo; Lefer, Barry; Loescher, Henry W.; Mirtl, Michael; Morris, Beryl; Muraoka, Hiroyuki; Noda, Hibiki M.; Paton-Walsh, Clare; Padea, Nicolas; Petzold, Andreas; Salmon, Emmanuel; Schaap, Dick; Scory, Serge; Rao, Krishna Achuta; Rathore, Jaswant; Steinbacher, Martin; Teutsch, Georg; Vermeulen, Alex; Yu, Xiubo; Zacharias, Steffen; Zhang, Leiming; Petäjä, Tuukka; Luterbacher, Jürg; Hannigan, James W.; Kulmala, Markku (Taylor and Francis, 2025-11-15)
To tackle the planetary environmental and climate crisis and meet the United Nations’ Sustainable Development Goals (SDGs), we must fully leverage the potential of Earth observations (EO). This involves integrating globally sourced data on the atmosphere, hydrosphere, cryosphere, lithosphere, along with ecological and socio-economic information. By harmonizing and integrating these diverse data sources, we can more effectively incorporate observational data into multi-scale modeling and artificial intelligence (AI) frameworks. This paper is based on discussions from the “Towards Global Earth Observatory” workshop held from May 8–10, 2023, organized by the World Meteorological Organization (WMO) and the Atmosphere and Climate Competence Center (ACCC), in collaboration with the Institute for Atmospheric and Earth System Research (INAR) at the University of Helsinki. The current state of EO and data repositories is fragmented, highlighting the need for a more integrated approach to establish a new global Ground-Based Earth Observatory (GGBEO). Here, we summarize the current status of selected in-situ and ground-based remote sensing observation systems and outline future actions and recommendations to meet scientific, societal, and economic needs. In addition, we identify key steps to create a coordinated and comprehensive GGBEO system that leverages existing investments, networks, and infrastructures. This system would integrate regional and global ground-based in situ and remote sensing systems, marine, and airborne observational data. An integrated approach should aim for seamless coordination, interoperable and harmonized data repositories, easily searchable and accessible data, and sustainable long-term funding.
Analysis of rainfall and temperature trends in Eswatini from 1981 to 2020 : a perspective of climate change and variability
Ndlela, Thandeka; Sifundza, Lungile S.; Beckedahl, Heinz; Kapwata, Thandi; Laban, Tracey L.; Mahlangeni, Nomfundo; Wright, Caradee Yael (Academy of Science of South Africa, 2026-01)
Rainfall and temperature are key climatic indicators essential for monitoring climate variability and change. Understanding long-term trends in these parameters is crucial for evidence-based policy formulation, particularly in vulnerable regions. We examined rainfall and temperature trends in Eswatini over a 40-year period (1981–2020) using meteorological data from five physiographic regions. Trends in monthly, seasonal and annual rainfall, alongside minimum and maximum temperatures, were analysed using the Mann–Kendall test and Sen’s slope estimator. The results reveal high interannual variability and shifting seasonal precipitation patterns, with an overall decline in annual rainfall. Statistically significant declines were noted in June and October, especially in the Lowveld and Highveld regions, whereas certain summer months (December to February) recorded increasing rainfall trends at some stations. Temperature analysis indicated significant warming trends in maximum temperature at four stations (Big Bend, Mbabane, Malkerns and Nhlangano), with increases in minimum temperature most evident in Mbabane and Big Bend. A cooling trend was observed at Mhlume in the Western Lowveld, highlighting geographic temperature variability. These findings align with regional studies that have reported increased climate variability across southern Africa. The results emphasise the urgency of implementing adaptive strategies, including improved water resource management and the development of early warning systems. This research provides a foundation for informed climate policy interventions in Eswatini. SIGNIFICANCE : This study provides a detailed assessment of long-term rainfall and temperature trends in Eswatini based on meteorological station data from 1981 to 2020. The findings show a general decline in rainfall and rising temperatures, with important seasonal and geographical differences across the country’s physiographic regions. These changes have implications for water availability, ecological function and the vulnerability of climate-sensitive ecosystems. By linking observed trends to broader regional patterns and known climate drivers such as the El Niño-Southern Oscillation, the study offers a baseline for national climate planning and contributes to a better understanding of climate variability in southern Africa.
Growth and physiological responses of two sugarcane cultivars exposed to elevated surface ozone
Laban, Tracey L.; Van Zyl, Pieter G.; Liebenberg, Shawn C.; Beukes, Johan P.; Berner, Jacques M.; Van Heerden, Philippus Daniel Riekert; Wright, Caradee Yael (Academy of Science of South Africa, 2026-01)
Surface ozone (O3) pollution is known to have a detrimental effect on agriculture whilst rising carbon dioxide (CO2) concentrations are sometimes found to offer plants protection against O3 effects. Considering the important role of sugarcane (Saccharum spp. hybrids) as a major food crop in South Africa and its contribution to the national economy, the tolerance of this crop to O3 damage must be established. A pilot study using open-top chambers was conducted whereby two local commercial sugarcane cultivars (NCo376 and N31) were fumigated during the summer growth season to explore the effects of elevated O3 as well as the interacting effects of O3 and CO2 on various stress and crop quality indicators. Statistical significance of differences in treatment means was analysed by hierarchical linear modelling to account for variability between chamber and pots in explaining changes across individual plants. The results revealed a significant reduction in the number of dead leaves (senescing) for the N31 cultivar exposed to elevated O3 compared with the other treatments. There was also a statistically significant decrease in chlorophyll fluorescence (used to assess photosynthetic performance) in the O3-treated NCo376 plants. This pilot study shows limited effects of O3 fumigation on growth and physiology, with preliminary indications that sugarcane is less sensitive to O3 than other crops. An increase in O3 concentrations associated with future climate change is expected, which will have implications for cultivar selection as a possible adaptation strategy to reduce susceptibility of this crop to O3. SIGNIFICANCE : • This article adds to the existing literature on sugarcane and ozone (O3). We present a pilot study for two cultivars of sugarcane and explore interacting effects of O3 and carbon dioxide (CO2) on various stress and crop quality indicators. • We employed a mixed effects model to account for variability between chamber and pots, a challenge when working with plants. • This is the first time African sugarcane has been investigated and, although the findings show limited statistical effect of O3 and CO2, future studies can vary the conditions of this experiment to produce more data points for a dose-response function.
African contributions are missing from cryosphere research in Africa and worldwide
Asante, Christian K.; Hansen, Christel D.; Hardy, Douglas R.; Hotaling, Scott (Frontiers Media, 2026-01-08)
No abstract available.
Land use/land cover (LULC) change and irrigated area monitoring in Eritrea : insights into horticultural production and sustainability
Haile, Bereket Tsehaye; Ramoelo, Abel; Dougill, Andrew J.; Qabaqaba, Mcebisi (Springer, 2025-12)
In arid and semi-arid regions, where water is scarce and climatic variability is high, monitoring changes in irrigated land is essential for ensuring food security and building resilience. However, few studies have assessed irrigation dynamics in the Horn of Africa using remote sensing, and empirical data from Eritrea remain limited. This study investigates the spatio-temporal dynamics of irrigated agriculture in two contrasting regions of Eritrea, Dighe and Gala Nefhi, using multi-temporal Sentinel-2 imagery and Supporting climatic and agricultural datasets from 2015 to 2024. It aims to map the spatial distribution of irrigated fields, assess their changes over time, and examine relationships with rainfall variability, horticultural crop production, and market fluctuations by comparing trends throughout the study period. A supervised Random Forest classification approach was implemented in Google Earth Engine, incorporating spectral indices and post-classification comparison to quantify the Land Use/Land Cover (LULC) transitions. The classification was based on dry-season imagery to distinguish irrigated from rainfed areas, with seven LULC classes identified. Overall classification accuracy ranged from 0.82–0.86 in Dighe and 0.87–0.89 in Gala Nefhi, with Kappa coefficients of 0.70–0.81 and 0.85–0.86, respectively. Results show a 115.5% increase in irrigated area in Dighe and 65.6% in Gala Nefhi. While Gala Nefhi showed synchronized growth in irrigation and horticultural crop production, Dighe exhibited inconsistent yields despite expanded irrigation. The study shows that expanding irrigation alone cannot increase production without reliable water sources, favorable climate conditions, and institutional support.
Drought, grazing, and nitrogen input influence nutrient supply and soil faunal activity in a semi-arid savannah grassland
Munjonji, Lawrence; Behn, Kai; Mokoka, Malesela Vincent; Ayisi, Kingsley Kwabena; Nielsen, Uffe; Linstädter, Anja (Nature Research, 2025-10-01)
Dryland grasslands cover approximately 16% of Earth’s land surface and support the livelihoods of people worldwide. However, the mechanisms driving their nutrient dynamics under changing environmental conditions remain poorly understood. This study, conducted in a dry savanna ecosystem in South Africa, investigated how grassland management interacted with drought and nitrogen addition in their effects on soil faunal activity and plant-available macro- and micronutrients. Extreme drought did not significantly affect soil invertebrates’ feeding activity in the top 8 cm, likely due to consistently dry conditions during the experimental period. In contrast, moderate grazing stimulated soil fauna feeding activity in the topsoil. Both nitrogen addition and grazing increased faunal activity, particularly at 7–8 cm depth. Drought conditions were associated with higher concentrations of manganese, zinc, and sulphur, while ambient rainfall conditions resulted in higher total nitrogen, magnesium, iron, and copper. Nitrogen addition enhanced mineral nitrogen availability and led to a fivefold increase in iron, and manganese, and doubling of copper. These findings suggest that moderate grazing management improves soil health in savanna grasslands, even under challenging climatic conditions.
Utility of UAS-LIDAR for estimating forest structural attributes of the Miombo woodlands in Zambia
Shamaoma, Hastings; Chirwa, Paxie W.; Zekeng, Jules C.; Ramoelo, Abel; Hudak, Andrew T.; Handavu, F.; Syampungani, Stephen (Public Library of Science, 2025-03-11)
The ability to collect precise three-dimensional (3D) forest structural information at a fraction of the cost of airborne light detection and ranging (lidar) makes uncrewed aerial systems-lidar (UAS-lidar) a remote sensing tool with high potential for estimating forest structural attributes for enhanced forest management. The estimation of forest structural data in area-based forest inventories relies on the relationship between field-based estimates of forest structural attributes (FSA) and lidar-derived metrics at plot level, which can be modeled using either parametric or non-parametric regression techniques. In this study, the performance of UAS-lidar metrics was assessed and applied to estimate four FSA (above ground biomass (AGB), basal area (BA), diameter at breast height (DBH), and volume (Vol)) using multiple linear regression (MLR), a parametric technique, at two wet Miombo woodland sites in the Copperbelt province of Zambia. FSA were estimated using site-specific MLR models at the Mwekera and Miengwe sites and compared with FSA estimates from generic MLR models that employed combined data from the two sites. The results revealed that the model fit of site-specific MLR models was marginally better (Adj-R2: AGB = 0.87–0.93; BA = 0.88–0.89; DBH = 0.86–0.96; and Vol = 0.87–0.98 than when using a generic combined data model (AGB = 0.80; BA = 0.81; DBH = 0.85; and Vol = 0.85). However, the rRMSE (2.01 – 20.89%) and rBias (0.01-1.03%) of site specific MLR models and combined data model rRMSE (3.40-16.71%) and rBias (0.55-1.16%) were within the same range, suggesting agreement between the site specific and combined data models. Furthermore, we assessed the applicability of a site-specific model to a different site without using local training data. The results obtained were inferior to both site-specific and combined data models (rRMSE: AGB = 36.29%–37.25%; BA = 52.98–54.52%; DBH = 55.57%–64.59%; and Vol = 26.10%–30.17%). The results obtained from this indicate potential for application in estimating FSA using UAS-lidar data in the Miombo woodlands and are a stepping stone towards sustainable local forest management and attaining international carbon reporting requirements. Further research into the performance of UAS-lidar data in the estimation of FSA under different Miombo vegetation characteristics, such as different age groups, hilly terrain, and dry Miombo, is recommended.

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