Over the past 40 years many hydraulic modelling systems for free-surface flows have been developed and successfully used in research and engineering practice. These systems were, in general, developed using sequential programming techniques while object-oriented programming approaches have only been used in the development of their visual parts. This paper outlines the approach used in the development of the NOAH modelling systems (Newcastle Object-oriented Advanced Hydroinformatics), developed entirely within the object-oriented paradigm. This novel approach has made NOAH modelling systems computationally highly efficient and yet easy to maintain and extend. NOAH 1D and NOAH 2D are designed to model free-surface flows in one and two dimensions, respectively. NOAH 1D is based on the full de Saint-Venant equations while NOAH 2D is based on the Shallow Water equations. Beside the basic ideas behind the development of NOAH modelling systems this paper also presents their main features and discusses general benefits of the application of the object-oriented programming approach in the development of numerical codes.
An object-oriented approach to the modelling of free-surface flows
