  Spatial phenomena are subject to scale effects, but there are rarely studies
addressing such effects on spatially embedded contact networks. There are two
types of structure in these networks, network structure and spatial structure.
The network structure has been actively studied. The spatial structure of these
networks has received attention only in recent years. Certainly little is known
whether the two structures respond to each other. This study examines the scale
effects, in terms of spatial extent, on the network structure and the spatial
structure of spatially embedded contact networks. Two issues are explored, how
the two types of structures change in response to scale changes, and the range
of the scale effects. Two sets of areal units, regular grids with 24 different
levels of spatial extent and census units of three levels of spatial extent,
are used to divide one observed and two reference random networks into multiple
scales. Six metrics are used to represent the two structures. Results show
different scale effects. In terms of the network structure, the properties of
the observed network are sensitive to scale changes at fine scales. In
comparison, the clustered spatial structure of the network is scale
independent. The behaviors of the network structure are affected by the spatial
structure. This information helps identify vulnerable households and
communities to health risks and helps deploy intervention strategies to
spatially targeted areas.
