The risk assessment results illustrated in Figure 10.18 greatly rests on the use of generic BPN
based risk models and the efficient management of relevant data in the GIS data base. The
number of assessed building structures is in the order of thousands why the development and
analysis of risks models for each individual building would not have been possible.
Besides providing a very efficient means for risk assessment the use of BPN’s in large scale
risk assessment also facilitates a consistent modelling of the relevant dependencies between
the parameters which influence the risk. Considering again the case of earthquake risk
assessment this concerns in particular the dependency in earthquake excitation of different
buildings, the dependency between damages of different building due to e.g. that they were
designed using the same design code, dependency between liquefaction failures at different
locations due to dependencies in soil properties, etc. It is very important that such
dependencies are included in the risk modelling as they will influence the results significantly.
The BPN’s readily allow for the inclusion of dependency between the risk associated with
different assets at different locations by use of common variables or nodes linking the
individual nets together.
Even though the general framework for GIS based risk management using BPN’s is relatively
well defined as outlined in the foregoing this type of decision support tool is still in its early
developments. There are still many interesting problems to be solved within this problem
complex and so far earthquake risks management models are among the better developed.
Similar frameworks must be developed for all relevant exposure types and in the end they
should be integrated into one GIS platform.