Coupled deductive database systems join together logic programming systems and relational database management systems, in order to combine the best of both worlds. The current state-of-the-art of these interfaces is restricted to access extensional data in databases in Datalog form, disallowing access to compound terms. However, recent years have seen the evolution of relational database management systems in order to enable them to store and manage more complex information. Of this complex data, one of the most interesting and fast growing is that of spatial data. In this paper we describe the application of the MYDDAS deductive database system to the handling of spatial data, and the needed extensions, namely the ability to handle vectorial geometric attributes from database relations, the definition of spatial operators, and a visualization framework, in order to obtain a spatial deductive database system, that can be used as a geographic information system. We argue that such a system can improve the state-of-the-art of spatial data handling in all of its aspects, namely in spatial data modeling, spatial querying and spatial data mining. We describe, in particular, the application of such a logic-powered geographic information system to two real-world problems.