The fourth generation of numerical modelling in hydraulics

Abstract

First-generation modelling was concerned only with computer adaptations of established, human-friendly methods. In second-generation modelling, on the other hand, methods were used that were more specifically “computer friendly†, even if “human-unfriendly†(e.g., finite-difference and finite-element methods). In third-generation modelling, these methods were incorporated into modelling systems, or “shells†, with which a model of any area could be constructed and run automatically by the system when provided with a suitably-formatted description of the area and its ancillary conditions. During the course of the second- and third-generation developments, however, modelling became an increasingly specialised and hermetic activity, confined for most practical purposes to computational-hydraulics experts. The fourth generation then builds on this earlier development, but in such a way as to provide modelling systems that can be used by professional engineers who are not computational-hydraulics experts. The paper describes a typical system for fourth-generation modelling, it outlines the manner of transformation of a third-generation system into a fourth-generation system, and it discusses some of the limits of fourth-generation modelling. It is emphasised that fourth-generation modelling demands a serious research commitment that is, however, not scientific research in its usually-understood sense.