  We show that precise knowledge of epidemic transmission parameters is not
required to build an informative model of the spread of disease. We propose a
detailed model of the topology of the contact network under various external
control regimes and demonstrate that this is sufficient to capture the salient
dynamical characteristics and to inform decisions. Contact between individuals
in the community is characterised by a contact graph, the structure of that
contact graph is selected to mimic community control measures. Our model of
city-level transmission of an infectious agent (SEIR model) characterises
spread via a (a) scale-free contact network (no control); (b) a random graph
(elimination of mass gatherings); and (c) small world lattice (partial to full
lockdown -- "social" distancing). This model exhibits good qualitative
agreement between simulation and data from the 2020 pandemic spread of
coronavirus. Estimates of the relevant rate parameters of the SEIR model are
obtained and we demonstrate the robustness of our model predictions under
uncertainty of those estimates. The social context and utility of this work is
identified, contributing to a highly effective pandemic response in Western
Australia.
