Spatial analysis for an evaluation of monitoring networks: examples from the Italian seismic and accelerometric networks

In this work, we propose a statistical
approach to evaluate the coverage of a network based
on the spatial distribution of its nodes and the target
information, including all those data related to the
final objectives of the network itself. This statistical
approach encompasses descriptive spatial statistics in
combination with point pattern techniques. As case
studies, we evaluate the spatial arrangements of the
stations within the Italian National Seismic Network
and the Italian Strong Motion Network. Seismic networks
are essential tools for observing earthquakes
and assessing seismic hazards, while strong motion
(accelerometric) networks allow us to describe seismic
shaking and to measure the expected effects on
buildings and infrastructures. The capability of both
networks is a function of an adequate number of
optimally distributed stations. We compare the seismic
network with the spatial distributions of historical
and instrument seismicity and with the distribution of
well-known seismogenic sources, and we compare the
strong motion station distribution with seismic hazard
maps and the population distribution. This simple
and reliable methodological approach is able to provide
quantitative information on the coverage of any
type of network and is able to identify critical areas
that require optimization and therefore address areas
of future development.