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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Now showing 1 - 20 of 923

How is climate science used to inform national-level adaptation planning in southern Africa?
Craig, Ailish; James, Rachel A.; Archer, Emma Rosa Mary; Daron, Joseph; Jack, Christopher D.; Jones, Richard G.; Kennedy-Asser, Alan T.; Lee, Jessica; McClure, Alice; Shaw, Christopher; Steynor, Anna; Taylor, Andrea; Vincent, Katharine (Taylor and Francis, 2026)
Climate model projections are increasingly being included within adaptation planning across sectors but there is limited understanding of how they are being used, and to what extent they improve adaptation planning. This article investigates how climate projections inform adaptation planning processes in the National Communications (NCs) to the United Nations Framework Convention on Climate Change (UNFCCC) in 16 southern African countries through a document analysis together with 18 key informant interviews. The study found that all the NCs include future climate model projections for the mid and/or late twenty-first century and focus on average changes in temperature and precipitation; meanwhile, the models, scenarios and time periods used vary between countries. The climate analysis is often detached from the adaptation planning section of the NC. The impacts and adaptation sections focus on key risks, such as flooding and drought and have limited recognition of uncertainties, suggesting plans are made without considering the full range of plausible futures. The role of climate science in the adaptation planning process varies, with some evidence of highly collaborative processes, resulting in evidence-based adaptation options across sectors and scales. In many cases, boundary agents play a key role in interpreting and communicating climate projections. We suggest that providing additional climate projections is unlikely to improve national adaptation planning, despite their scientific benefits. Instead, the focus should be on developing approaches and collaborative processes to distil and interpret climate information in different contexts, to enable decision-makers to understand the range of plausible futures, including changes in climate alongside growing populations, urbanization and changing economies. KEY POLICY INSIGHTS • Climate data analysis in policy documents is often limited to average temperature and rainfall, and the average of many models, which may underestimate emerging risks, for example, from heat and sea level rise. • Climate data analysis is sometimes detached from impact assessment and adaptation options; a potential barrier to rigorous decision-making. • Collaborative processes can integrate climate science into risk assessment and adaptation planning, with a key role for boundary agents. • Improving evidence-informed adaptation planning requires the interpretation of information through a collaborative process.
Using data science to identify climate change and health adverse impacts and solutions in Africa : a scoping review
Wright, Caradee Yael; Jaca, Anelisa; Kapwata, Thandi; Naidoo, Natasha; Awokola, Babatunde; Bainomugisha, Engineer; Berhane, Kiros; Blesic, Suzana; Kehbila, Anderson Gwanyebit; Naidoo, Rajen N.; Nemukula, Bono; Nyarko, Benjamin Kofi; Okekunle, Akinkunmi Paul; Oni, Tolu; Qunasah, Reginald; Thiam, Sokhna; Zakari, Ibrahim Sidi; Beyene, Negussie; Chimusa, Emile R.; Webster, Candice (Nature Research, 2026-02)
Africa is experiencing the impacts of climate change. While global epidemiological studies using traditional analytical methods to study the relations between climate change and health exist, studies using data science to tackle these topics are increasing. The aim of this study was to identify how data science is being used to understand climate change impacts on health in Africa. We carried out a scoping review to synthesize the evidence of data science applied to understand health outcomes associated with climate change in Africa. Among 100 included articles, several temporal and spatial analytical tools and models were applied to determine the relationships between climate change factors and health outcomes for morbidity and mortality. For example, early warning systems for malaria were the most studied adaptation intervention. Africa has a wealth of evidence for addressing the health impacts of climate change to inform solutions for Africa and other countries around the world.
Urban and power plant NOx emissions in Sub-Saharan Africa inferred from TROPOMI
Marais, Eloise Ann; Wei, Nana; Tan, Eric Y.P.; Lu, Gongda; Keita, Sekou; Naidoo, Mogesh; Garland, Rebecca M. (Wiley, 2026-02)
Please read abstract in the article.
Socio-demographic and environmental factors associated with tuberculosis infection among children less than 15 years in Hhohho region of Eswatini (Swaziland)
Gwebu, Adam B.; Naidoo, Natasha; Wright, Caradee Yael (Frontiers Media, 2026-02-10)
OBJECTIVE : Tuberculosis (TB) is one of the most prevalent public health challenges, particularly in developing countries where poverty, lack of sanitation and improper housing exacerbate the spread of infectious diseases. This study aimed to determine the socio-demographic and environmental factors associated with TB infection among children in the Hhohho region of Eswatini. METHODS : We conducted a cross-sectional study among children under 15 years diagnosed with TB (2022–2023) in Eswatini's Hhohho region, identified through hospital records. Data were collected via a structured survey and medical record review to assess environmental and socio-demographic risk factors. A Social Vulnerability Index (SVI) was constructed using 13 binary indicators to quantify cumulative social and environmental disadvantage. Social Vulnerability Index (SVI) from the Centers for Disease Control and Prevention (CDC) was utilised to investigate whether higher vulnerability correlates with a greater prevalence of TB symptoms. RESULTS : A high proportion (64%) of children were socially vulnerable, indicating multidimensional disadvantage. Children who are socially vulnerable face a significantly higher burden of TB symptoms (94%) compared to their less vulnerable peers (78%). Thus, social disadvantage directly increases health risks in children. The Expanded SVI therefore serves as an important indicator of social determinants of TB risk in the study population CONCLUSION : These results strongly suggest a need for targeted public health interventions that prioritize children who are economically disadvantaged. There is an ever-increasing need for policies that address upstream social determinants such as poverty, overcrowding, and poor nutrition that heighten TB risk.
Smart cartography for sustainable development : International Cartographic Conference 2023
Coetzee, Serena Martha; Delmelle, Eric; Huang, Haosheng (Taylor and Francis, 2026)
The 31st International Cartographic Conference 2023 (ICC 2023) was held in Cape Town, South Africa, from 13 to 18 August 2023. The theme of ICC 2023 was “Smart cartography for sustainable development,” emphasizing the significant roles of cartography in turning abstract spatial data into meaning and in providing human-centered and actionable insights to achieve the 17 Sustainable Development Goals (SDGs) of the UN.
Factors motivating community participation in the Bushbuckridge municipality in the Mpumalanga province of South Africa
Breetzke, Gregory Dennis; Mthimunye, Sanelisiwe (Routledge, 2026)
Participation is a fundamental component of any community enrichment programme. Current knowledge and understanding about what motivates communities to participate in local community initiatives are however limited, especially in a South African context. This study aimed to identify the factors that motivates local community members to participate in the construction and running of early childhood development (ECD) centres in the Bushbuckridge municipality in the Province of Mpumalanga. To achieve this aim, we engaged with Team Frank Africa – a non-profit organization (NPO) that builds and runs early childhood development (ECD) centres in the municipality with the assistance of local community members. Two focus group discussions were held with local community members, and two interviews were held with Team Frank members to identify what motivates local community participation in these ECDs. Findings revealed that community participation in this context is largely driven by self-interest, and a sense of ownership. Overall findings reaffirm the fact that community participation is a complex process, and its determinants are highly influenced by personal and socio-economic circumstances. We believe that the study contributes to our understanding of community participation in a rural South African context as well as contributes knowledge to the sustainability of future community development programmes in similar contexts.
Heat in the transport sector: measured heat exposure and interventions to address heat-related health impacts in the minibus taxi industry in South Africa
Wright, Caradee Yael; Kapwata, Thandi; Kunene, Siyathemba; Kwatala, Ngwako; Mahlangeni, Nomfundo; Laban, Tracey; Webster, Candice (Springer, 2025-10)
High temperatures, heat and heatwaves are being experienced more frequently and with greater intensity in many parts of the world, including South Africa, and record-breaking maximum temperatures are becoming more common. Exposure to heat has adverse impacts on human health and wellbeing. The transport sector and its users are vulnerable to heat both inside vehicles as well as in places where people wait for public transport. We sought to assess the temperatures experienced in minibus taxis, a common mode of transport in South Africa and in minibus taxi ranks as well as the heat-related perceptions of minibus taxi drivers working in the Chesterville Taxi Association in Durban. We also observed heat-related elements in minibus taxi ranks. Data from temperature loggers showed that temperatures inside minibus taxis reached up to 39 °C and were between 3-4 °C warmer than outdoors. For around 11 h every day, temperatures inside minibus taxis were warmer than 27 °C - the temperature that is linked to heat-health symptoms. Taxi drivers (N = 16) all agreed they feel hot in the minibus taxi and more than 90% said they drink water to try to cool down. Taxi ranks were lacking in supply of drinking water and shade for minibus taxis and seating. With the projected increase in temperatures caused by climate change, it is imperative to co-develop mitigation and adaptation strategies to minimise heat-related human health impacts in minibus taxis and taxi ranks especially in low- and middle-income countries.
The under-representation of the global South on editorial boards in criminology
Breetzke, Gregory Dennis (International Journal of Crime Justice and Social Democracy, 2025-12)
Less than 5% of editorial board members across all 69 journals listed under the Criminology and Penology category of Clarivate’s Web of Science database have affiliations with institutions in the Global South. Moreover, editorial board members from the Global South are significantly more likely to sit on lower “quality” journals than their Global North counterparts. The extreme skewness in regional representation of editorial board membership is symptomatic of a broader marginalization of the Global South in academia in general, and criminology specifically. The study’s findings should be of importance (and concern) to all criminologists who believe that a more diverse, equitable, and inclusive representation of scholars across all phases of the academic publishing process is key to better understanding the context of crime: a global problem. A number of recommendations are outlined that can be used to increase the regional representativeness of editorial boards.
The impact of rising ambient temperatures on the mental and physical health of children
Wright, Caradee Yael; Norval, Mary; Naidoo, Natasha; Bulani, Muthise; Coovadia, Ashraf; Theron, Linda C. (Elsevier, 2025-09)
Globally, mean ambient temperatures have increased by 1.6 °C between preindustrial level and 2024, alongside a rise in extreme weather events such as heatwaves and droughts. This rapid review synthesizes the existing literature on the risks to children’s physical and mental health due to heat exposure. Comprehensive literature searches were conducted using PubMed, Scopus, Web of Science, and ScienceDirect. This review highlights the increased risks to children’s physical and mental health from extreme temperatures in several populations. Major health concerns include heat-related illnesses, dehydration, increasing incidence of infectious diseases, reduced cognitive performance, depression and anxiety and the exacerbation of pre-existing conditions. Potential strategies to mitigate these negative health outcomes are proposed, including improved access to cooling solutions, public health interventions, and educational campaigns to improve thermal comfort. HIGHLIGHTS • Children are vulnerable to a range of physical and mental health impacts from excessive ambient temperatures. • The physical effects of heat extend beyond the typical heat illness symptoms such as heat stroke. • Kidney disease, cardiovascular disease, asthma and respiratory conditions are among the most common effects of heat on children. • The negative mental health effects of heat are associated with cognitive, behavioural and major psychological effects. • Healthcare providers must be trained to recognize and treat heat-related illnesses, while strategies like improving access to cool spaces and conducting further research are crucial for fostering resilience and mitigating future health risks.
Determination of South African carbon dioxide emission factors for selected solid fuels
Kornelius, Gerrit; Forbes, Patricia B.C.; Garland, Rebecca M. (Academy of Science of South Africa, 2026-03-26)
South Africa’s National Climate Change Response Policy requires accurate reporting of greenhouse gas (GHG) emissions. To achieve this, the South African Department of Forestry, Fisheries and the Environment initiated a process to develop country-specific emission factors (referred to as Tier 2 factors by the Intergovernmental Panel on Climate Change (IPCC)) for fuels produced or used locally, which are more accurate than those currently used (Tier 1). In this work, we report on the development of such county-specific emission factors for the solid fuels most commonly produced and used in South Africa, based on the analysis of 107 samples. The samples received were classified into types based on the IPCC fuel classification method, which has some differences from that used in South Africa. The CO2 emission factor for sub-bituminous coal, mainly used for power generation and in the liquid fuels/chemical sectors of South Africa, was found to be 97 807 kg CO2/TJ. For ‘other bituminous coal’, the CO2 emission factor was found to be 101 171 kg CO2/TJ. These emission factors are higher than the IPCC default (also referred to as Tier 1) factors, which have been in use in South Africa to date. As solid fossil fuel use is a major contributor to South Africa’s GHG emissions, this implies higher than previously estimated CO2 emissions from this sector as well as a higher contribution to global emissions. SIGNIFICANCE: • South African Tier 2 carbon dioxide emission factors for solid fuel use are reported for the first time, as required by South Africa’s commitments under the United Nations Framework Convention on Climate Change and the Paris Climate Agreement. • The Tier 2 carbon dioxide emission factors were derived from the analysis of over 100 South African solid fuel samples. • Emission factors for the fuels used in the largest amounts are higher than the default Tier 1 factors previously used, leading to an increase in reported emissions for a similar fuel use. • The main user of coal in South Africa, the power generation sector, uses sub-bituminous coal based on the IPCC classification system, which includes volatile matter as a classification criterion. • Using the same IPCC criteria, the majority of samples from other South African industrial and commercial users are classified as ‘other bituminous coal’.
Linking the ultraviolet index to the shadow rule for sun protection : a theoretical model applied with a southern hemisphere example
Wright, Caradee Yael; Downs, Nathan J.; Kapwata, Thandi; Du Preez, David Jean; Tod, Bianca (Wiley, 2026-01)
Personal solar ultraviolet radiation (UVR) exposure has positive and negative impacts on human health. Excess solar UVR exposure can be avoided through safe sun practices such as using sun protection and avoiding unprotected outdoor exposure when solar UVR levels are high. The shadow rule indirectly determines the sun's altitude by observing the length of a person's shadow during the course of the day. When the shadow cast by the sun on a horizontal surface is shorter than the height of the person casting the shadow, the solar UVR intensity is high and is deemed to have more risk. The magnitude of this risk depends on factors such a skin type, sun protection used etc. The UV Index is a standardized measure to describe the intensity of solar UVR with respect to the human action spectrum for sunburn. It is frequently reported in weather forecasts aimed at the public. Here, we demonstrate the potential utility of the shadow rule and how it may be understood in relation to the UV Index in a subtropical southern hemisphere setting. Its use as a simple awareness tool for sun protection in locations where the UV Index is not made public has value in promoting sun exposure awareness and reducing personal exposure risk.
Adoption of sustainable pest management practices by horticultural farmers in Eritrea
Haile, Bereket Tsehaye; Dougill, Andrew J.; Ramoelo, Abel (Taylor and Francis, 2026)
Pesticide misuse poses considerable health and environmental risks, particularly in regions with weak regulatory enforcement and limited institutional capacity. This study examines the adoption of sustainable pest management practices among 170 horticultural farmers in the moist highlands and arid lowlands of Eritrea, with a focus on the prevalence and type of synthetic pesticide use, adoption of safe handling and application practices, and non-chemical pest control measures. Most farmers reported using WHO Class II pesticides to control pests like aphids, caterpillars, mites, and others. Notable regional differences were found in the adoption of safe pesticide use practices, with low adopters of safe practices being more prevalent in Gala Nefhi than in Dighe. Extension services and training on pesticide safety emerged as the most consistent predictors of adoption levels. Non-chemical alternatives such as biopesticides (5.3%) and biological control (4.1%) were reported to be underutilized. Evidence-based strategies aimed at improving adoption of safe pesticide use practices, enhancing institutional outreach, and promoting low-risk pest control methods are necessary in support of Eritrea’s agricultural sustainability goals.
A risk assessment framework for communicable diseases in informal settlements : a case study of COVID-19 in Melusi, City of Tshwane, South Africa
Sempe, Nhlanhla Pheletso Suzan; Davis, Nerhene; Rautenbach, Victoria; Coetzee, Serena Martha (Routledge, 2026)
Approximately one billion people live in slums or other conditions of informality that are particularly vulnerable to the outbreak of communicable diseases. The COVID-19 pandemic has raised concerns over the ability to manage such outbreaks in informal settlements. To plan and implement appropriate public health responses, risks must first be assessed. However, current risk assessment frameworks for communicable diseases either do not assess risk at the informal settlement scale or they consider only a small number of influencing factors. In this research, a risk assessment framework for informal settlements was developed, informed by a review of assessment frameworks and factors that facilitate the spread of the COVID-19 virus. Subsequently, the framework was implemented and evaluated for Melusi, an informal settlement in the city of Tshwane, South Africa. Results reveal that, in the context of COVID-19, the greatest exacerbators of vulnerability for the Melusi community were the dwelling structures; access to water and handwashing facilities and the dirty state of communal toilets. The community’s preparedness was strengthened by access to masks, a stable diet, healthcare and comorbidity management, despite the pandemic. Resilience was mainly due to households relying on multiple energy sources. The framework proved to have replication value but can be refined by collecting qualitative data from a wider group of participants and exploring novel ways for collecting quantitative data.
Visualising population distribution with choropleth maps : which classification methods are suitable for South African population data?
Snyman, Lourens Fourie; Coetzee, Serena Martha (Taylor and Francis, 2026)
ABSTRACT : Choropleth maps are among the oldest and still one of the most frequently used techniques for visualising quantitative data, such as population density. Today, each geographic information system (GIS) has a plethora of options for categorising data into classes for choropleth maps. Each option has its pros and cons, depending on the data and the use case. This paper presents the results of a user study to assess the suitability of different data classification methods for effectively visualising population distribution with choropleth maps in South African metropolitan areas. The research focused on geographic accessibility as a use case: population density is visualised on choropleth maps, allowing decision makers to identify over- or underserved areas for the provisioning of facilities. Results show that respondents were more likely to provide correct answers when presented with maps visualising data classified according to quantiles and natural breaks (Jenks), suggesting that these are easier to interpret for assessing and understanding population distribution in South Africa. RÉSUMÉ : Les cartes choroplèthes sont parmi les cartes les plus anciennes et sont encore parmi les cartes les plus fréquemment utilisées pour visualiser des données quantitatives telles que des données de densité de population. Aujourd'hui tous les systèmes d'information géographique ont de nombreuses options pour catégoriser les données en classes pour faire des cartes choroplèthes. Chaque option a des avantages et inconvénients, selon les cas d'étude et les utilisations. Cet article présente les résultats d'une étude utilisateur visant à évaluer l'adéquation de différentes méthodes de classification de données pour la visualisation efficace des distributions de population dans les régions métropolitaines d'Afrique du Sud. Cette recherche est centrée sur l'accessibilité géographique comme cas d'utilisation : la densité de population est visualisée sous la forme de cartes choroplèthes, permettant aux décideurs d'identifier les zones sur- ou sous-desservies en services. Les résultats montrent que les participants ont plus de chance de donner les bonnes réponses avec des cartes classées en fonction des quantiles et des ruptures naturelles (Jenks), ce qui suggère que ces cartes sont plus faciles à interpréter pour évaluer et comprendre la distribution de la population en Afrique du Sud.
Predicting smallholder maize yield using sentinel-2-derived phenological metrics
Masiza, Wonga; Nkuna, Basani Lammy; Ratshiedana, Phathutshedzo Eugene; Madasa, Akhona; Nduku, Lwandile; Shwatja, Tumelo; Chirima, Johannes George; Nyamugama, Adolph; Abutaleb, Khaled; Khoboko, Pitso Walter; Hamandawana, Hamisai (Elsevier, 2026-03)
Please read abstract in the article. HIGHLIGHTS • Phenological metrics derived from multiple spectral indices are used to predict maize yields. • Regularized linear models were trained with limited data to predict maize yields. • Pre-peak and cumulative integrals of red-edge indices best predicted maize yield. • Parsimonious models trained with key features showed no measurable loss of accuracy.
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.

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