Community Gardens as Small-Scale Nature-Based Solutions in Upgraded Informal Settlements: Spatial Typologies and Decision-Support Insights from Bangkok

Nature-based solutions (NbS) are widely recognised for their potential to deliver ecological and socio-economic benefits across diverse urban contexts. However, the spatial design and long-term governance of NbS in dense, land-constrained environments remain underexplored. This paper examines community gardens (CGs) and everyday greening practices as small-scale NbS within such settings, focusing on three upgraded informal settlements in Bangkok, Thailand, developed under the Baan Mankong (“secure housing”) participatory social housing programme.

The study adopts a comparative lens to examine how CGs operate as adaptable and socially embedded NbS in contexts where land scarcity and competing priorities constrain urban greening. Using an exploratory mixed-methods design, we combine (1) spatial typology analysis to identify constraints and opportunities for greening; (2) NDVI time-series analysis (2018–2025) derived from PlanetScope imagery to monitor vegetation patterns over time; (3) household surveys capturing ecosystem service aspirations, perceived benefits, and disservices; and (4) semi-structured interviews with community leaders, long-term gardeners, and technical partners. Together, these methods form an analytical framework for evaluating existing CGs and informing future small-NbS design in upgraded informal settlements.

The findings show that while urban CGs are frequently celebrated for their multifunctionality, their form and social benefits are strongly shaped by spatial configuration, institutional arrangements, and modes of community stewardship within which they are placed. Across the three settlements – characterised by clustered, linear canal-edge, and grid-like high-connectivity spatial forms – CGs exhibit distinct patterns of accessibility, participation, and stewardship among community members. These spatial differences further influence perceived benefits and disservices, as well as patterns of land use, labour burdens, and leadership dynamics. Collectively, the findings illuminate the functionality and dynamics of CGs as small-scale NbS and contribute to the development of a decision-support framework for the design and assessment of small-scale NbS in dense, land-constrained urban environments.