Urban Transformation Between Built and NaturalSystems by Means of an Adapted Wave FunctionCollapse Approach

Abstract

In practice, urban transformation is often carried out at the outskirts or in between existing areas of a city. In that context, important questions are: How can one imagine a transition between different urban structures? What if, additionally, we aim for including not only the development from innermost to outermost but also vice versa – letting nature into the city rather than the other way around? What are the implications of interventions on the surroundings? Addressing these questions requires a modelling approach that links local morphological compatibility between urban structures with macroscale socio-economic feedback driving development, vacancy and ecological change. To that end, we combine complementary modelling components. A cellular-automaton (CA) grid provides the spatial representation and hosts rule-based land-use transitions over time. Within this structure, an adapted Wave Function Collapse (WFC) operator infers context-sensitive land-use changes from learned adjacency relations, ensuring morphological compatibility of infill and transformation. A system-dynamics (SD) layer generates macro-scale pressures in households, jobs and capital that drive development, vacancy and decline across the grid. Evolution over time emerges from the CA rule system and from vacancy-driven transformations derived from previous work on urban cell grammars, extending WFC from a static pattern generator to a dynamic operator of urban change. Our framework is intended for use in planning, but also in education and policy making (“What-If”-Scenarios). The system supports both conventional development trajectories and their inversion: not only densification and infill, but also decline, abandonment, and ecological succession where nature re-enters under conditions of sustained vacancy.