Nowadays, classical conceptual models (such as ER or UML) are used for designing database applications. These classical conceptual models usually come with associated CASE tools assisting the user from the creation of the conceptual schema until the generation of a physical schema for a relational or an object-relational DBMS. However, when developing spatial or temporal databases such classical models are inadequate since they do not consider spatiotemporal concepts. Although spatial and/or temporal extensions have been proposed for these models, such extensions do not cope with the requirements of advanced geographical applications, in particular, they do not cope with multiple representations of the same real-world phenomenon. In the context of the European project MurMur we developed a conceptual model called MADS coping with spatio-temporal information having multiple representations. Typical examples of multiple representation arise with multi-scale or time-varying information. ...