The most populated (urban) area in Sri Lanka is its Western Province with Colombo, Sri Lanka’s commercial capital. This “Megapolis” depends for its food supply significantly on different geographical areas of Sri Lanka. These foodsheds differ by commodity. Peri-urban agriculture plays a minor role and until very recently, urban farming did not get (institutional) attention, although the role of both, urban and peri-urban agriculture is mentioned in the national agricultural policy. The policy also calls for the identification and strengthening of city region food system (CRFS) to better link rural and urban communities, also in view of climate shocks and other disasters. The need for this became clear during the Covid-19 epidemic and subsequent economic crisis of the country when the Colombo Municipal Council started actively to support urban food production.

Over the last thirty years, Ghana’s population in towns and cities has more than tripled, from 4 million to nearly 14 million, exceeding growth in the rural areas. In fact, rural-urban migration is an important factor for urban growth. It is estimated that the urban population will reach over 70% by 2050, calling for fast and sustainable strategies for facilitating the main challenges deriving from rapid urbanization including urban food security and food system resilience against shocks. Several projects mapped urban foodsheds and the overall extent of specific city-region food systems. But not only food quantity, also food safety is at stake. A particular challenge for the farmers is widespread water pollution in urban area resulting in the contamination of irrigated vegetables. The largely informal nature of irrigated urban vegetable farming as well as the street food sector makes it difficult to regulate, promote or control compliance with food safety measures which are needed from farm to fork.

In contexts where conventional environmental monitoring has historically been limited, citizen science (CS) for monitoring efforts can be an effective approach for decentralized data generation that also raises scientific literacy and environmental awareness. To that end, the United Nations Environmental Program (UNEP) is considering citizen science (CS) as a mechanism for producing ambient water quality data to track progress on Sustainable Development Goal (SDG) indicator 6.3.2: quot;proportion of bodies of water with good ambient water qualityquot;. However, the alignment of SDG 6.3.2 monitoring requirements with citizen science capacity and results in low- or middle-income countries has not been assessed. Through a systematic literature review of 49 journal publications, complemented by 15 key informant interviews, this article examines the methods and outputs of CS programs in resource-constrained settings. We explore the potential of these programs to contribute to tracking SDG 6.3.2. Using the Citizen Science Impact Assessment Framework (CSIAF), we evaluate broader outcomes of CS programs across 5 domains: society, economy, environment, governance, and science and technology. Despite large variability in scope, CS programs were consistently found to generate useful data for national-level reporting on physicochemical and ecological parameters; however, data quality is a concern for CS measurement of microbiological parameters. The focus in literature to-date is predominantly on scientific data production which falls only within the apos;science and technologyapos; outcome domain. Societal, governance, economic, and environmental outcomes are infrequently evaluated. Of the studies reviewed in this article, 75% identified some form of pollution but only 22% of them reported follow-up actions such as reporting to authorities. While CS has important potential, work is still needed towards the apos;formalizationapos; of CS, particularly if intended for more vulnerable contexts.