ABSTRACT
The word “model” is one that is used commonly in everyday language, and has a
range of meanings. Dictionary definitions include “a three-dimensional
reproduction of something, usually on a smaller scale”, “a design or style of
structure, e.g. this year’s model”, and “to design or plan (a thing) in accordance
with a model, e.g. the new method is modelled on the old one”. However, when the
term is used in an engineering context it is often quite specific and conceptually
different. To an engineer a model can be defined as an “abstraction of reality”
(Izquierdo et al., 2004). This concept is illustrated in Figure 1.1 (Dandy et al.,
2008) where a real world system (e.g. a bridge, highway, open channel, or dam
wall) that needs to be understood sufficiently to make predictions about how it will
behave under a range of situations is conceptualised in an idealised form, which is
then analysed. This conceptualisation leads to the development of a model and
forms an important part of engineering design. Based on the analysis that is then
carried out, the properties of the real world system are inferred.