Theoretical study on modular division and combination of distributed hydrological models

On the basis of existing distributed hydrological models, the Formal Concept Analysis method is applied to identify the basic equations describing the major hydrological processes. A hierarchy framework of new concepts derived from this method is established by combining these basic equations. The Hassle graph can be used to illustrate the structure of the new concepts and using as an essential guideline for model users to develop plug-in modules for the future customized hydrological models. The generation process of surface runoff is adopted as a case study to verify the feasibility of the proposed method.