Environmental Engineering Reference
In-Depth Information
of the International Society for Ecological Modelling in 1975, the topic was fully
established as a conceptionally and methodologically expanding science.
To meet the demands of empirical complexity, it became necessary to involve
additional methods. Most of these additional methods were again imported from
other disciplines and adapted to ecological requirements and then yielded the
repertoire of modelling complex ecological dynamics.
3.4 Diversification and Diversifiers
During the 1980s it became apparent that homogeneous variables had a limited
potential to fully capture the complexity of ecological relations. In particular,
quantity-quality transitions and inhomogeneous temporal and spatial structures
were difficult - at least inconvenient - to be captured in differential equation
systems. Criticisms towards modelling as such (e.g. den Boer 1981) would be
overcome when modelling methodologies diversified.
The Object Paradigm and Individual-Based Modelling
During the 1960's, Ole Johann Dahl (1931-2002) (Fig.
3.6
) and Kristen Nygaard
(Fig.
3.7
) from the Norwegian Computer Centre in Oslo developed a computer
language which went conceptually beyond the established so-called procedural
approach: With SIMULA (SIMUlation LAnguage), extending ALGOL (ALGO-
rithmic Language) they introduced options that allowed a kind of self-structuring
during programme execution (Dahl et al. 1968). Reference variables could point to
particular addresses of the computer storage to indicate the location of complex
data objects. These data objects could be created and deleted when running the
programme and utilize references to each other that could be changed during
execution. This yielded
object-oriented programming
, which became generally
known in computer science with the SMALLTALK-80 programming language
Fig. 3.6 Ole-Jan Dahl,
courtesy of Depart. of
Informatics, University of Oslo
