  We study geographical effects on the spread of diseases in lattice-embedded
scale-free networks. The geographical structure is represented by the
connecting probability of two nodes that is related to the Euclidean distance
between them in the lattice. By studying the standard Susceptible-Infected
model, we found that the geographical structure has great influences on the
temporal behavior of epidemic outbreaks and the propagation in the underlying
network: the more geographically constrained the network is, the more smoothly
the epidemic spreads.
