Maintenance of multiple representation databases for topographic data

The maintenance and updating of geo-databases has today become an urgent pr oblem in national mapping agencies. In this paper, the problem is approache d by introducing a model for a multiple representation database (MRDB) syst em. The term 'multiple representation' refers to a database structure in wh ich several representations at various scales of the same geographic object are included. This structure offers several advantages, one of which is th at an MRDB satisfies the varying multi-purpose needs of geographic data in a flexible manner and offers a means for solving updating problems. The sys tem can be supported by an object-oriented approach. However, the most cent ral requirement for the system is that bidirectional connectivities are sup ported among the various representations. This requirement has been examine d in a case study that ws implemented in an object-oriented GIS environment s. The differences between an MRDB system and a traditional map-product dat abase system are illustrated and discussed.