A solute and water flux library for catchment models

Simple coupling of models can be inhibited by overlapping process descriptions and differing spatial and temporal scales. However the process of bringing together multiple models can be enhanced if at least one of the models provides capabilities to adjust itself to the more specific requirements of other models. Key design considerations in the development of such models include successive layers of abstraction in the process description, and efforts to preserve generality of process description in deep layers of specialization. Object orientated design of model code, using generalized interfaces, is one way to create such functionality. The advantages of an object oriented code structure for hydrological models, even without the utilization of inheritance, were outlined by Wang et al. [2005].