  Urban evolution processes occur at different scales, with intricate
interactions between levels and relatively distinct type of processes. To what
extent actual urban dynamics include an actual strong coupling between scales,
in the sense of both top-down and bottom-up feedbacks, remains an open issue
with important practical implications for the sustainable management of
territories. We introduce in this paper a multi-scalar simulation model of
urban growth, coupling a system of cities interaction model at the macroscopic
scale with morphogenesis models for the evolution of urban form at the scale of
metropolitan areas. Strong coupling between scales is achieved through an
update of model parameters at each scale depending on trajectories at the other
scale. The model is applied and explored on synthetic systems of cities.
Simulation results show a non-trivial effect of the strong coupling. As a
consequence, an optimal action on policy parameters such as containing urban
sprawl is shifted. We also run a multi-objective optimization algorithm on the
model, showing showing that compromise between scales are captured. Our
approach opens new research directions towards more operational urban dynamics
models including a strong feedback between scales.
