Research Artcicles (Geography & Environmental Studies)

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Cultivating food justice: redefining harvest sales for sustainable urban agriculture in low-income Cape Town post Covid-19
(John Wiley and Sons Inc, 2024) Kanosvamhira, Tinashe P.
It is well established that urban community gardens (UCGs) can either challenge or reinforce neoliberal urbanism. This duality is especially evident among UCGs that sell garden harvests for income generation. In this article I therefore examine UCGs in low-income areas of Cape Town, South Africa, to understand how they might sell their harvests while countering the neoliberal food system in cities of the global south. I draw on qualitative fieldwork, including observations and semi-structured interviews with UCG representatives and civil society actors. Most harvests are currently sold to high-end venues through intermediary actors in civil society organizations (CSOs) and non-governmental organizations (NGOs). However, this approach disregards the local community's socioeconomic conditions and undermines community gardens’ nutritional objectives. Yet, under specific scenarios, the sale of garden harvests could mitigate the persistent food injustice in Cape Town's low-income areas. In this article I introduce a model for harvest sales that advances sustainable urban agriculture and fosters food justice in neoliberal cities in the global south.
Exploring the potential of remote sensing to facilitate integrated weed management in smallholder farms: a scoping review
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Gokool, Shaeden; Sibanda, Mbulisi; Mahomed, Maqsooda
In light of a growing population and climate change compounding existing pressures on the agri-food system, there is a growing need to diversify agri-food systems and optimize the productivity and diversity of smallholder farming systems to enhance food and nutrition security under climate change. In this context, improving weed management takes on added significance, since weeds are among the primary factors contributing to crop yield losses for smallholder farmers. Adopting remote-sensing-based approaches to facilitate precision agricultural applications such as integrated weed management (IWM) has emerged as a potentially more effective alternative to conventional weed control approaches. However, given their unique socio-economic circumstances, there remains limited knowledge and understanding of how these technological advancements can be best utilized within smallholder farm settings. As such, this study used a systematic scoping review and attribute analysis to analyse 53 peer-reviewed articles from Scopus to gain further insight into remote-sensing-based IWM approaches and identify which are potentially best suited for smallholder farm applications
Comparing the utility of artificial neural networks (ANN) and convolutional neural networks (CNN) on sentinel-2 msi to estimate dry season aboveground grass biomass
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Vawda, Mohamed Ismail; Lottering, Romano; Sibanda, Mbulisi
Grasslands are biomes of significant fiscal, social and environmental value. Grassland or rangeland management often monitors and manages grassland productivity. Productivity is determined by various biophysical parameters, one such being grass aboveground biomass. Advancements in remote sensing have enabled near-real-time monitoring of grassland productivity. Furthermore, the increase in sophisticated machine learning algorithms has provided a powerful tool for remote sensing analytics. This study compared the performance of two neural networks, namely, Artificial Neural Networks (ANN) and Convolutional Neural Networks (CNN), in predicting dry season aboveground biomass using open-access Sentinel-2 MSI data. Sentinel-2 spectral bands and derived vegetation indices were used as input data for the two algorithms. Overall, findings in this study showed that the deep CNN outperformed the ANN in estimating aboveground biomass with an R2 of 0.83, an RMSE of 3.36 g/m2 and an RMSE% of 6.09. In comparison, the ANN produced an R2 of 0.75, an RMSE of 5.78 g/m2 and an RMSE% of 8.90. The sensitivity analysis suggested that the blue band, Green Chlorophyll Index (GCl), and Green Normalised Difference Vegetation Index (GNDVI) were the most significant for model development for both neural networks. This study can be considered a pilot study as it is one of the first to compare different neural network performances using freely available satellite data. This is useful for more rapid biomass estimation, and this study exhibits the great potential of deep learning for remote sensing applications.
Comparing machine learning algorithms for estimating the maize crop water stress index (CWSI) using UAV-acquired remotely sensed data in smallholder croplands
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Kapari, Mpho; Sibanda, Mbulisi; Magidi, James
Monitoring and mapping crop water stress and variability at a farm scale for cereals such as maize, one of the most common crops in developing countries with 200 million people around the world, is an important objective within precision agriculture. In this regard, unmanned aerial vehicle-obtained multispectral and thermal imagery has been adopted to estimate the crop water stress proxy (i.e., Crop Water Stress Index) in conjunction with algorithm machine learning techniques, namely, partial least squares (PLS), support vector machines (SVM), and random forest (RF), on a typical smallholder farm in southern Africa. This study addresses this objective by determining the change between foliar and ambient temperature (Tc-Ta) and vapor pressure deficit to determine the non-water stressed baseline for computing the maize Crop Water Stress Index. The findings revealed a significant relationship between vapor pressure deficit and Tc-Ta (R2 = 0.84) during the vegetative stage between 10:00 and 14:00 (South Africa Standard Time). Also, the findings revealed that the best model for predicting the Crop Water Stress Index was obtained using the random forest algorithm (R2 = 0.85, RMSE = 0.05, MAE = 0.04) using NDRE, MTCI, CCCI, GNDVI, TIR, Cl_Red Edge, MTVI2, Red, Blue, and Cl_Green as optimal variables, in order of importance. The results indicated that NIR, Red, Red Edge derivatives, and thermal band were some of the optimal predictor variables for the Crop Water Stress Index. Finally, using unmanned aerial vehicle data to predict maize crop water stress index on a southern African smallholder farm has shown encouraging results when evaluating its usefulness regarding the use of machine learning techniques. This underscores the urgent need for such technology to improve crop monitoring and water stress assessment, providing valuable insights for sustainable agricultural practices in food-insecure regions.
Crop mapping in smallholder farms using unmanned aerial vehicle imagery and geospatial cloud computing infrastructure
(Elsevier Ltd, 2024) Gokool, Shaeden; Sibanda, Mbulisi; Mahomed, Maqsooda
Smallholder farms are major contributors to agricultural production, food security, and socio-economic growth in many developing countries. However, they generally lack the resources to fully maximize their potential. Subsequently they require innovative, evidence-based and lower-cost solutions to optimize their productivity. Recently, precision agricultural practices facilitated by unmanned aerial vehicles (UAVs) have gained traction in the agricultural sector and have great potential for smallholder farm applications. Furthermore, advances in geospatial cloud computing have opened new and exciting possibilities in the remote sensing arena. In light of these recent developments, the focus of this study was to explore and demonstrate the utility of using the advanced image processing capabilities of the Google Earth Engine (GEE) geospatial cloud computing platform to process and analyse a very high spatial resolution multispectral UAV image for mapping land use land cover (LULC) within smallholder farms. The results showed that LULC could be mapped at a 0.50 m spatial resolution with an overall accuracy of 91%. Overall, we found GEE to be an extremely useful platform for conducting advanced image analysis on UAV imagery and rapid communication of results.
A disposable diaper collection project in Langa, Cape Town, South Africa: a pilot study
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Schenck, Catherina; Grobler, Lizette; Niyobuhungiro, Rissa; Kimani, Alexander
In developing countries, there is currently no established waste management plan that includes resource recovery from used disposable diapers (DDs) apart from incineration and landfilling. In low-income areas with limited storage space, the complex composition and odour of used DDs make it impossible to manage properly if not supported by effective waste management systems. In the absence of effective waste management, DDs are dumped in open spaces, burned or buried. These actions pose threats to the safety and health of humans, animals and the environment. Separation and collection of DDs are critical preliminary steps to landfilling, recycling or beneficiation. In this article, we describe a case study of two pilot collection projects in Langa township in Cape Town, South Africa, to determine whether and how a source-separated collection system can work in low-income, resource-constrained areas. The lessons learned highlighted the following: The eagerness of parents to participate for the benefit of their own and their children’s health; the complementarity of the two pilot collection models to serve the needs of the community; the important role non-government organisations play in the implementation of waste management projects; the significance of the possible job creation opportunities and the unintended benefits of enhancing social cohesion. The financial sustainability of these projects needs further exploration.
The institutionalisation of urban community gardens in Cape Town, South Africa
(John Wiley and Sons Inc, 2024) Kanosvamhira, Tinashe Paul
Urban community gardens, once seen as a counter to neoliberal subjectivity, are now perceived as inadvertently reinforcing neoliberal dominance, challenging the progressive goals of urban gardening. This study investigates how the state shapes urban community gardens in alignment with neoliberal principles, potentially diluting their intended advantages. By analysing policies and interviewing state actors supporting urban gardening initiatives and activists, I argue that the state actively cultivates neoliberal subjectivities in these contexts. Unfortunately, state policies and projects often fail to address the root causes of food and nutrition insecurity in urban areas. This neoliberalisation of urban community gardening diminishes their potential to act as tools for advancing food justice in historically disadvantaged communities in Cape Town. Nevertheless, there is hope in the agency of gardeners who are not passive participants in this process. I conclude that relying on the state to implement projects for a more equitable food system may not be a dependable strategy. Instead, urban gardeners must carefully select their allies to effectively pursue their goals. The information, practices and views in this article are those of the author(s) and do not necessarily reflect the opinion of the Royal Geographical Society (with IBG).
Unveiling quiet activism: Urban community gardens as agents of food sovereignty
(John Wiley and Sons Inc, 2024) Kanosvamhira, Tinashe Paul; Tevera, Daniel
Urban community gardening is emerging as a form of quiet activism challenging the corporate food system. In urban community gardening, quiet activism subtly challenges the dominant corporate food system. However, research tends to overlook its presence and impact in global South cities, where issues of food insecurity and corporatisation are acute. There is a gap in research on urban community gardening activism, with a focus mainly on global North cities. Global South cities and populations face unique challenges in the corporate food system that require attention and exploration in scholarly literature. We draw on qualitative research conducted with urban community gardeners in Cape Town, South Africa. Through interviews and observations, the study investigates how these gardeners engage in quiet activism to challenge the corporate food system. We find that community gardens are subtle but potent platforms for bolstering local food movements and fostering healthier dietary practices by cultivating and sharing produce. Quiet activism through community gardening offers a nuanced approach to challenging the corporate food system. The study highlights the need to recognise and understand varying levels of activism intensity and their implications for reshaping urban food systems. We underscore the need to discern the distinct embodiments necessitated by different modes of activism.
Experimental urban commons?: Re-examining urban community food gardens in Cape Town, South Africa
(John Wiley & Sons Ltd, 2023) Kanosvamhira, Tinashe Paul; Follmann, Alexander; Daniel, Tevera
Contemporary literature on urban agriculture often analyses urban community gardens as ‘existing’ commons with the capacity to counter neoliberal urban development and resource management practices. However, the existing literature on ‘political gardening’ generally focuses on cities in North America and Europe, despite the prevalence of urban community gardens and neoliberal planning across other regions, including Southern cities. This paper examines urban community gardens in Cape Town, South Africa to assess their capacity to function as urban commons in six areas: infrastructure, inputs, land, produce, labour and immaterial components. This mixed‐methods study employed questionnaires, semi‐structured interviews and observations across 34 urban community gardens in the city. The findings and analysis demonstrate how the urban community gardens counter neoliberal privatisation and individualisation processes. However, their capacity to function as urban commons is significantly curtailed by an entrenchment within the neoliberal context. Thus, the urban community gardens are framed as ‘experimental’ commons, a valuable re‐conceptualisation of alternative resource utilisation in neoliberal Southern cities.
How do we get the community gardening? Grassroots perspectives from urban gardeners in Cape Town, South Africa
(Taylor and Francis Group, 2023) Kanosvamhira, Tinashe P.
Urban agriculture offers numerous environmental, economic, and socialbenefits. However, it is often hampered by limited engagement in cities of theglobal South. This article offers bottom-up perspectives on how to increasethe uptake of urban agriculture activities. It draws on urban gardeners�perspectives in the low-income neighbourhood of Mitchells Plain, Cape Town.The mixed-methods approach combined a questionnaire survey, semi-structured interviews with urban gardeners, and interviews with civil societyactors and a state official. The results indicate that climate and soil conditionsare major deterrents to urban agriculture. However, community dialoguesabout urban agriculture�s social and environmental benefits could play acrucial role in increasing uptake and in facilitating conversations about urbanagriculture and food more generally. The paper offers recommendations forfuture interventions seeking to promote urban agriculture and support actorsin low-income neighbourhoods in Cape Town and other African cities.
Urban agriculture and the sustainability nexus in South Africa: Past, current, and future trends
(Springer, 2023) Kanosvamhira, Tinashe P.
Urban agriculture remains a topical issue that needs to be better understood in striving for sustainable cities, particularly in sub-Saharan Africa. Through a literature review, this article examines urban agriculture studies in South Africa to identify trends, opportunities, and gaps in the literature. The article examines the discourses that have emerged based on a narrative literature review of 62 peer-reviewed articles from 1993 to 2022. The findings indicate that several gaps in the knowledge limit our understanding of the practice of urban agriculture toward sustainable cities, for instance, an under-representation of secondary cities and the general productivist focus of most studies in the country. The author argues that future research needs to focus on underrepresented cities using rich methodologies to gain further insights into urban agriculture and its place in the city.
Assessing the prospects of remote sensing maize leaf area index using uav-derived multi-spectral data in smallholder farms across the growing season
(MDPI, 2023) Buthelezi, Siphiwokuhle; Mutanga, Onisimo; Sibanda, Mbulisi
Maize (Zea Mays) is one of the most valuable food crops in sub-Saharan Africa and is a critical component of local, national and regional economies. Whereas over 50% of maize production in the region is produced by smallholder farmers, spatially explicit information on smallholder farm maize production, which is necessary for optimizing productivity, remains scarce due to a lack of appropriate technologies. Maize leaf area index (LAI) is closely related to and influences its canopy physiological processes, which closely relate to its productivity. Hence, understanding maize LAI is critical in assessing maize crop productivity. Unmanned Aerial Vehicle (UAV) imagery in concert with vegetation indices (VIs) obtained at high spatial resolution provides appropriate technologies for determining maize LAI at a farm scale. Five DJI Matrice 300 UAV images were acquired during the maize growing season, and 57 vegetation indices (VIs) were generated from the derived images.
Boundaries of benefit sharing: interpretation and application of substantive rules in the Lake Malawi/Niassa/Nyasa sub?basin of the Zambezi Watercourse
(Springer, 2023) Fatch, Joanna; Bolding, Alex; Swatuk, Larry A.
questions regarding how riparian states determine �who gets what, where, and why� in a shared watercourse. To facilitate peaceful coexistence, substantive rules��equitable and reasonable utilisation (ERU)� and �the duty to prevent the causing of significant harm�� define rights and responsibilities of riparian states in the utilisation of shared watercourses. The duty of riparian states to cooperate, as a principle of international law, plays an important part in realising these substantive rules. This article critically reflects on the principles underlying transboundary water management by focusing on the interpretation and application of substantive rules in the Lake Malawi/Niassa/Nyasa sub-basin of the Zambezi River Basin in Southern Africa. The case study demonstrates how interpretation and application of international water law are generally in line with customary practices, but are subject to highly localised decision contexts which challenge Southern African Development Community (SADC) attempts to establish a firm legal foundation upon which to guide access, use and management across the region�s shared river basins.
Public space and the cohesion-contestation spectrum
(GeoJournal, 2023) Middelmann, Temba; Rawhani, Carmel
The urban policy assumption of public space�s generative capacity for cohesion stands out as limited in the face of the reality of South African urban public space. Drawing on observations and experiences in a range of Johannesburg public spaces, we critique the assumption contained in international, national, and local South African urban policies about cohesive public space. We argue that assuming the agency of people as tending towards cohesion and that the agency of space is enough to ensure this because it is necessarily similarly cohesive, is incorrect. Likewise, assuming the primacy of the agency of space is misleading. This dichotomy of relationships focusing on space as cohesive, and people as influenced by space, requires a third element.
Pathways to food insecurity: Migration, hukou and Covid?19 in Nanjing, China
(Wiley) Crush, Jonathan; Xu, Fei; Zhong, Taiyang
The COVID?19 pandemic has issued significant challenges to food systems and the food security of migrants in cities. In China, there have been no studies to date focusing on the food security of migrants during the pandemic. To fill this gap, an online questionnaire survey of food security in Nanjing City, China, was conducted in March 2020. This paper situates the research findings in the general literature on the general migrant experience during the pandemic under COVID and the specifics of the Chinese policy of hukou. Using multiple linear regression and ordered logistic regression, the paper examines the impact of migration status on food security during the pandemic. The paper finds that during the COVID?19 outbreak in 2020, households without local Nanjing hukou were more food insecure than those with Nanjing hukou. The differences related more to the absolute quantity of food intake, rather than reduction in food quality or in levels of anxiety over food access. Migrants in China and elsewhere during COVID?19 experienced three pathways to food insecurity�an income gap, an accessibility gap, and a benefits gap. This conceptual framework is used to structure the discussion and interpretation of survey findings and also has wider potential applicability.
Black Belonging, White Belonging: Primitive Accumulation in South Africa's Private Nature Reserves
(Wiley, 2023) Thakholi, L; Koot, S
victions have been shown to be a mechanism of primitive accumulation in nature conservation. This paper adds an historical analysis to the discussion on primitive accumulation in conservation by exploring the seemingly innocuous mechanism of White belonging to land in South Africa's private nature reserves. Contemporary articulations of White belonging are replete with stories and images of White male �pioneers� from the colonial era who, upon arrival in �empty lands�, were able to create economies out of nothing. Such representations of history on private nature reserve websites and other promotional material invisibilise Black belonging and legitimise private conservation. By illuminating the inconsistencies in the empty lands narrative and the legacies of three championed conservation pioneers from the 19th century, this paper argues that White belonging is a mechanism of primitive accumulation, while Black belonging continues to be expressed in various ways in contemporary South Africa.
Covid-19 and urban food security in Ghana during the third wave
(MDPI, 2023) Onyango, Elizabeth Opiyo; Owusu, Bernard; Crush, Jonathan S.
While the effects of the COVID-19 pandemic on household food security have been documented, the intensity and forms of food insecurity in urban households in the Global South have not been adequately explored. This is despite the emerging consensus that impacts of the pandemic were more severe in urban than rural Africa. This paper addresses this knowledge gap by examining the relationship between pandemic precarity and food insecurity in Ghana�s urban areas during the COVID-19 pandemic in 2020. This study is based on the World Bank (WB) and Ghana Statistical Service (GSS) COVID-19 High-Frequency Phone Survey. Using a sub-sample of 1423 urban households, the paper evaluates household experiences of the pandemic. Our findings show that household demographic characteristics are not a major predictor of food insecurity. Economic factors, especially the impact of the pandemic on wage income and total household income, were far more important, with those most affected being most food insecure.
Crop monitoring in smallholder farms using unmanned aerial vehicles to facilitate precision agriculture practices: A scoping review and bibliometric analysis
(MDPI, 2023) Gokool, Shaeden; Mahomed, Maqsooda; Sibanda, Mbulisi
In this study, we conducted a scoping review and bibliometric analysis to evaluate the state-of-the-art regarding actual applications of unmanned aerial vehicle (UAV) technologies to guide precision agriculture (PA) practices within smallholder farms. UAVs have emerged as one of the most promising tools to monitor crops and guide PA practices to improve agricultural productivity and promote the sustainable and optimal use of critical resources. However, there is a need to understand how and for what purposes these technologies are being applied within smallholder farms. Using Biblioshiny and VOSviewer, 23 peer-reviewed articles from Scopus andWeb of Science were analyzed to acquire a greater perspective on this emerging topical research focus area.
'Africanisation' of South Africa's international air links, 1994-2003
(Elsevier, 2006) Pirie, Gordon
In the first decade of democratic rule in South Africa scheduled commercial passenger flights across the country�s borders more than doubled. Additional flights served new African air passenger markets and secondary airports in established markets. Overseas flights increased more slowly, serving a diminishing number of overseas countries and cities. In 1994 the Republic was linked directly by air with more overseas than African countries and cities; within a decade the pattern reversed. The changing geography of South Africa�s international air links reflects developments in the international airline industry, and South Africa�s increasingly prominent political and commercial role in Africa.
Mapping the spatial distribution of underutilised crop species under climate change using the MaxEnt model: A case of KwaZulu-Natal, South Africa
(Elsevier, 2022) Mugiyo, Hillary; Chimonyo, Vimbayi G.P.; Sibanda, Mbulisi
Knowing the spatial and temporal suitability of neglected and underutilised crop species (NUS) is important for fitting them into marginal production areas and cropping systems under climate change. The current study used climate change scenarios to map the future distribution of selected NUS, namely, sorghum (Sorghum bicolor), cowpea (Vigna unguiculata), amaranth (Amaranthus) and taro (Colocasia esculenta) in the KwaZulu-Natal (KZN) province, South Africa. The future distribution of NUS was simulated using a maximum entropy (MaxEnt) model using regional circulation models (RCMs) from the CORDEX archive, each driven by a different global circulation model (GCM), for the years 2030 to 2070. The study showed an increase of 0.1�11.8% under highly suitable (S1), moderately suitable (S2), and marginally suitable (S3) for sorghum, cowpea, and amaranth growing areas from 2030 to 2070 across all RCPs. In contrast, the total highly suitable area for taro production is projected to decrease by 0.3�9.78% across all RCPs. The jack-knife tests of the MaxEnt model performed efficiently, with areas under the curve being more significant than 0.8. The study identified annual precipitation, length of the growing period, and minimum and maximum temperature as variables contributing significantly to model predictions.

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