Research & reports

Adili Y. Zella · African Journal of Social Issues · Tanzania

This study analyzed land use and land cover (LULC) changes in Kinondoni District, Dar es Salaam, Tanzania, between 1993 and 2023 using multi-temporal Landsat satellite imagery. The analysis revealed that built-up areas expanded by 1,433%, from 124.20 ha in 1993 to 1,905.14 ha in 2023. Concurrently, cultivated land decreased by 96.6%, from 172.90 ha to 5.88 ha, representing a loss of 167.02 ha. The near-complete elimination of cultivated land in Kinondoni District indicates a critical threat to local food production capacity and urban food security.

James Vandenberg, Kerstin Krellenberg · Sustainable Cities and Society · Global

This study investigated how differentiated configurations of outdoor, indoor, and greenhouse urban agriculture (UA) impact Urban Resilience Capacities (URCs). It found that a strategic, place-based, combinatorial approach to integrating UA typologies can produce mutually reinforcing outcomes, strengthening various URCs simultaneously. However, a strong risk of trade-offs exists when UA systems are not aligned, and a critical research gap remains as empirical case studies are concentrated in Europe and North America, overlooking experiences in the Global South.

Joan Casanelles-Abella, Monika Egerer · Frontiers in Sustainable Cities · Global

A perspective article discusses biodiversity conservation in cities as often afflicted by "suboptimal" situations where human needs and nature's needs are imbalanced or in conflict. In human-dominated landscapes, land use intensification often replaces large habitat patches critical for metapopulation stability with smaller, isolated patches, a pattern Island Biogeography Theory predicts will reduce biodiversity; this may be most extreme in cities experiencing rapid population growth and infrastructure densification, where small urban green spaces, balconies, home and allotment gardens, small forest patches and green walls, become the primary compensatory interventions for retaining habitat. However, under certain conservation frameworks (land-sparing vs. land-sharing, the SLOSS debate), such small, scattered urban green spaces may be predicted to produce suboptimal or even detrimental biodiversity outcomes if their size and isolation prevent them from sustaining viable population sizes. The article notes this "ecology of suboptimals" framing risks a futile perspective on nature conservation in densifying cities, while also considering how rethinking urban environments in light of this situation might be approached.

Margarethe Karpe, Jeremías Lachman, Lili Wang, L.F.M. Marcelis, E. Heuvelink · Sustainable Production and Consumption · Global

A Delphi survey with 108 experts explored urban agriculture's potential contributions to Sustainable Development Goals (SDGs) under a scenario of 30% urban food self-sufficiency. Experts identified SDG 7.2 (renewable energies) as a key challenge due to high energy use, and agreed that none of the evaluated SDG targets for urban agriculture will be met by 2030. They also noted a lack of regulations and public policies for innovative agricultural systems.

Alex Barimah Owusu, Collins Adjei Mensah, Clement Kwang, Gerald Albert Baeribameng Yiran, Ronald Reagan Gyimah, Dominic Edem Hotor, Princella Ofori Darko · International Planning Studies · Ghana

This paper analyzed the replacement of green spaces with brown spaces in Accra, Ghana, from 1991 to 2021 using Landsat satellite images. Brown areas increased from 24.5% in 1991 to 81% in 2021, while green areas decreased from 75.5% to 19% during the same period. The study found a significant reduction in green spaces due to urbanization.

Marcus Robinson, Jacky Bowring, Shannon Davis, Sarah Edwards · Landscape Research · Global

This narrative review explored how urban expansion at the rural-urban fringe drives the loss of productive agricultural land, biodiversity, and ecosystem services. The review examined how these competing interests can be negotiated spatially, emphasizing the role of multifunctional green infrastructure to integrate both food production and ecological function across the urban-rural continuum.

Sumit Vij, Vishal Narain · Wiley Interdisciplinary Reviews Water · Global

This review addresses a knowledge gap on how peri-urban residents in Asia and Africa adapt to the impacts of urbanization and climate change on water security. As rural-urban boundaries rapidly blur in the global South, peri-urban spaces are characterized by weakening access to water resources, depleting common property institutions and poor civic engagement, and the review presents the persistent marginalization of peri-urban residents from a water security perspective, while also showing that they do develop adaptation measures. Existing literature is found to focus primarily on (1) increased vulnerability of peri-urban agriculture and allied sectors, (2) barriers and enablers to water-security-related adaptation planning, and (3) justice in peri-urban areas, and the review calls for further study of emerging cooperation and collective action that could reduce conflicts between peri-urban and urban inhabitants and improve water security.

Dongxiang Chen, Yuanming Wang, Haijun Bao · Habitat International · Global

This research extended the land sharing and sparing framework to urban land use, quantifying the impact of urban services, food production, and ecosystem services. The results showed that land-sparing scenarios had a 23.6% lower overall value loss than sharing scenarios on average. However, while land-sparing mitigates losses in food production and ecosystem services, it increases the cost of urban services, creating a trade-off that challenges achieving an optimal win-win situation.

Ronald O. Muchelo, Thomas F. A. Bishop, Sabastine U. Ugbaje, Stephen Akpa · Land · Uganda (Kampala)

This study examined urban growth and agricultural land loss in Kampala (1989-2015) and Mbarara (2002-2016), Uganda, using multi-temporal Landsat imagery. Kampala's urban area surged from 7.14% to 55.10%, and Mbarara's from 6.37% to 30.95%, while agricultural land decreased significantly in both cities. A substantial portion of urban growth encroached upon agricultural land (66.7% in Kampala, 57.8% in Mbarara), and unsustainable practices also converted wetlands and forests to agricultural land.

Madison Powers · · Global

This chapter surveys the food-security implications of agricultural land use, unsustainable features of widespread food production practices, and the debate over agricultural intensification versus extensification, then examines land use's consequences beyond the land itself for groundwater, surface water, oceans, ambient air quality, and planetary systems. It explains the causes of forest destruction and fragmentation driven by the global expansion of land used for "high-risk commodities," the linkage between deforestation and declining terrestrial biodiversity, and the global market dynamics driving both crises. It assesses socioeconomic and ecological shortcomings in some proposed nature-based solutions, showing that they perpetuate an unsustainable business-as-usual approach, and summarizes how these land-use issues are conceptualized as human-rights concerns and translated into policy proposals.

Ayşegül YARIŞ, Emel Karakaya Ayalp · Zenodo (CERN European Organization for Nuclear Research) · Global

The current agri-food system is undergoing an unsustainable transition, with Urban Food Planning emerging as a holistic approach for sustainable transition. This paper explains and translates the "City-Region Food System (CRFS) Toolkit," developed in partnership with FAO, RUAF, and participating cities. It examines the toolkit's roadmap and approach for building more sustainable and resilient urban food systems through two case studies in West Africa. The research concluded that the CRFS Toolkit defines limited tools for building sustainable urban food systems and excludes the relationship with spatial disciplines.

CHRISTINA FELIX KIFUNDA · Asian Journal of Agriculture · Tanzania

Combining 30 years of temperature and rainfall data from the Tanzania Meteorological Agency with a questionnaire survey of 386 urban-agriculture households across five wards of Kinondoni City (Bunju 118, Kunduchi 42, Mabwepande 102, Mzimuni 28, Wazo 96), plus focus group discussions, key informant interviews and direct observation, this study examined climate change's effects on urban crop production and farmers' adaptation strategies. More than 70% of surveyed smallholder farmers were aware of climate change indicators, consistent with the meteorological data, citing rising temperature (76%) and declining rainfall (73%); pests and diseases were ranked highest (88%) among significant climate-change effects. Land scarcity was also identified as a significant challenge for urban agriculture, and pesticide and fertilizer use was the most commonly cited adaptation strategy (65%).

Imen Bendjemila, Salah Chaouche · DOAJ (DOAJ: Directory of Open Access Journals) · Algeria

Urban sprawl in N'Gaous, Algeria, expanded its land area by over ten times (from 33.7 to 379.7 hectares) and its population by over six times (from 4,887 to 33,515 persons) over 60 years. This rapid growth creates significant issues, particularly for peri-urban orchards, which are the primary economic activity. The study used an analytical approach with Geographic Information Systems to assess the agronomic potential of soils and quantify agricultural land consumed by construction, aiming to achieve an optimal agri-urban balance rather than merely avoiding urban expansion.

Stella Kabiri, Molly Allen, Judith Tomma Okuonzia, Beatrice Akello, Rebecca Ssabaganzi, Drake N. Mubiru · Open Research Africa · Uganda

This study investigated the extent of wetland loss and encroachment by urban agriculture in Wakiso and Kampala, Uganda, over 30 years from 1986 to 2016. Using field surveys, Landsat, and MODIS NDVI data, the analysis found that 72,828 ha (73%) of Wakiso-Kampala wetlands were lost, while agricultural areas doubled. Of this, 16,488 ha (23%) were converted from wetlands, with all cultivated agriculture in Kampala occurring in wetlands and 73% in Wakiso.

Imen Bendjemila, Salah Chaouche · Prostor : znanstveni časopis za arhitekturu i urbanizam · Algeria

This study investigated urban growth and urbanization in N'Gaous, Algeria, over the last 60 years, using an analytical approach and Geographic Information Systems to assess the agronomic potential of soils. It found that N'Gaous experienced significant urban sprawl, with its land area expanding over ten times and population increasing more than six times, leading to serious issues for peri-urban orchards. The study quantified and monitored the agricultural potential consumed by construction, highlighting the negative impact of urban expansion on agricultural land.

Carlos Tapia, Linda Randall, Shinan Wang, Luciane Aguiar Borges · Sustainable Cities and Society · Denmark (Aarhus)

This study presents a novel indicator-based evaluation framework for urban agriculture, tested in Fællesgartneriet Brabrand, a community garden in Aarhus, Denmark. The framework aims to capture the contribution of gardening practices to urban sustainability, acknowledging that urban agriculture may also have social and environmental externalities depending on prevalent farming practices.

Fatiha Hakimi · Journal of Analytical Science & Technology · Morocco (Rabat)

This study assessed the practices, roles, and challenges of peri-urban farming in the metropolis of Rabat, Morocco, surveying 50 respondents. Peri-urban agriculture is a multifunctional activity contributing to job creation, income generation, food supply, and environmental beautification. However, it faces several constraints, including precarious and costly labor, absence of regulating laws, lack of training and technical supervision for peri-urban farmers, and water resource shortages.

Salvatore Engel‐Di Mauro, George M. Martin · · Global

This chapter examines urban cultivation across diverse global contexts, finding that global South cities often experience declining food production due to displacement by financiers and landowners. It notes that urban cultivation is frequently associated with unacknowledged pollution problems, and its overall ecological impacts are not necessarily positive. Furthermore, urban food production, with the exception of Cuba, does little to reduce social inequality and can sometimes exacerbate it.

Carolina Baldini, Mariana Edith Marasas, Andrea Alejandra Drozd · Journal of Environmental Planning and Management · Colombia

A land-cover change study (Journal of Environmental Planning and Management, 2021) applied a supervised classification of Landsat satellite imagery from 1986, 1996, 2005, and 2015 to Argentina's largest peri-urban horticultural region in South America. Between 1986 and 2015, open-field horticulture extent decreased by 51.47%, while greenhouse area increased by 2652.83%, high-density urbanization expanded by 111.58%, and low-density urbanization increased only between 1986 and 2005—expansion that came at the expense of natural grassland, herbaceous parks, and livestock land. The authors conclude this reflects a regional process of urban growth and productive intensification that has caused losses of open-field horticultural areas and produced a non-equitable distribution of remaining semi-natural areas, and they call for territorial planning that prioritizes ecologically resilient, semi-natural land cover.

Aamir Mehmood Shah, Gengyuan Liu, Fanxin Meng, Qing Yang, Jingyan Xue, Stefano Dumontet, Renato Passaro, Marco Casazza · Energies · Global

This review article examines knowledge gaps regarding small-scale urban green-blue infrastructure (GBI) from the perspective of the food-energy-water (FEW) nexus, focusing on the literature on urban ecosystem services (positive effects) and dis-services (negative effects) associated with different GBI typologies. It found that GBI can contribute environmentally, socially, and economically to FEW security and urban sustainability, but that these positive effects must be weighed against ecosystem dis-service tradeoffs: urban food production is commonly connected with heavy water and energy consumption, particularly under dry climate conditions, and is sometimes linked to excessive use of manure, pesticides, or fertilizers that can pose risks to water quality and local insect survival, or to enhanced mosquito breeding from irrigation. The review also found that few nexus modeling techniques have been discussed in terms of their benefits, drawbacks, and applications.

Alessio Russo, Giuseppe T. Cirella · Humanities and Social Sciences Communications · Global

This comment examines "edible urbanism 5.0," noting that urban and peri-urban agriculture can have negative effects on city ecosystems, which urbanists and planners have largely overlooked. It highlights the need for a concept that considers trade-offs between ecosystem services and disservices, especially given current unsustainable industrial intensive farming. Edible urbanism aims to integrate food security, resilience, and social inclusion through edible green infrastructure and modern food production.

Asnath Alberto Malekela · · Tanzania

In Dar es Salaam, Tanzania, a study of climate change impacts on urban and peri-urban agriculture (UPA) drew on secondary literature plus primary data from structured and in-depth interviews, observations, and focus group discussions with 201 UPA practitioners. 84% of respondents engaged in UPA for food and income, and UPA made a positive contribution to food security. However, UPA was found to be severely affected by climate change: effects included drying of crops (41%), crop pests and diseases (28%), decreased crop yields (13%), loss of soil fertility (8%), animal diseases (43%), drying of pasture lands (41%), and livestock deaths (16%). The study states plainly that urban and peri-urban agriculture in Dar es Salaam is severely affected by climate change, and recommends adopting farming systems such as vertical farming that use limited water resources.

Michael Martin, Elvira Molin · Sustainability · Sweden

This study assessed the environmental impacts of urban vertical hydroponic farming through a life-cycle perspective, applied to a case-study vertical hydroponic farm in Stockholm, Sweden, comparing current performance with potential improvement scenarios. Results showed that growing medium, pots, electricity demand, and transportation of raw materials and product deliveries were the important contributors to environmental impact in this system. Replacing plastic pots with paper pots was found capable of producing large reductions in GHG emissions, acidification impacts, and abiotic resource depletion, and replacing conventional gardening soil with coir as the growing medium also led to large impact reductions. However, the study states that further reducing the system's impacts will require more resource-efficient steps specifically to address impacts from electricity demand, an issue not resolved by the pot and growing-medium substitutions, and identifies potential for more symbiotic exchanges using urban wastes and by-products.

Runrid Fox-Kämper · · Global

This book provides insights and examples of how urban space is negotiated, describing urban gardens as "lived places" where social relations, meanings, and a sense of place are developed. To trigger social benefits, it is essential that these sites fulfill more functions than just food growing and leisure. Horticultural practices, such as using pesticides or fertilizers, have a strong influence on the ecological impact of urban gardening; although awareness among gardeners has increased due to training programs in recent decades, this impact persists.

Guy M. Robinson, Zhiling Liu · AIMS environmental science · Australia

This paper examines the contradictions between greening and "ungreening" in Adelaide, South Australia, focusing on the city's Park Lands and urban sprawl. It argues that urban sprawl, including recent development on prime farmland, has been antithetical to biodiversity maintenance and greening principles, reducing sustainability capacity. The paper identifies problems such as conflict between biodiversity and protecting residents in bushfire risk areas, stemming from a relaxed attitude towards low-density expansion.