Where does Plastic Waste go? Integrating Material, Social, and Spatial Dimensions. Lessons from Indonesia

Context. Plastic waste management is a complex and systemic challenge. The generation and handling of waste are embedded in local governance arrangements, everyday practices, and urban spatial conditions. Although recent advances in Urban Metabolism (UM) and Material Flow Analysis (MFA) research highlight the need for more integrative perspectives on material flows, much of the literature still isolates waste generation and disposal practices from their urban and social contexts, overlooking intra-urban differences. Goal. The goal of the thesis is to develop a systemic and spatially grounded understanding of plastic waste flows by examining how social structures, urban landscapes, and individual agency interact to shape these flows. The thesis has three interrelated objectives. First, to understand how plastic waste flows vary across different urban areas and assess whether these variations are statistically and spatially significant. Second, to explore the interplay of individual motivations, social dynamics, and neighbourhood urban conditions shaping household plastic waste sorting practices. Third, to analyse the built environment and psychological factors associated with the presence of illegal dumpsites and litter. Method. Five administrative wards (kelurahan), comprising 54 neighbourhoods (Rukun Warga) in Bandung, Indonesia, were selected as a case study. Data were collected through mobile-based georeferenced household surveys (n =1539) and geotagged photo mapping of litter, illegal dumpsites, and disposal facilities. First, plastic waste flows were quantified across each kelurahan using a georeferenced, bottom-up MFA. Second, spatial clustering and regression analyses were used to examine the drivers and barriers of household plastic waste sorting. Third, correlation analyses and regression models were used to identify built environment and psychological factors associated with proximity to litter and dumpsites. Results. The analysis reveals significant disparities in plastic waste consumption and disposal practices across kelurahan, with substantial variation across all examined flows. Spatial analysis reveals a clear pattern: waste sorting clusters in areas with neighbourhood-based initiatives. Regression models indicate that accessibility, local leadership, and effective collection systems support waste sorting. Conversely, visible pollution, infrastructural constraints, high population density, and mistrust in government effectiveness reduce the likelihood of waste sorting. Lastly, household proximity to dumpsites and litter is associated with the absence of collection services, inadequate roads and wastewater infrastructure, and high population density. It also correlates with lower perceived environmental self-efficacy and education among residents. Conclusion. This interdisciplinary work moves beyond fragmented, sector-specific analyses by integrating social, spatial, and behavioural dimensions into the study of plastic waste flows