In this paper we address the problem of formalizing qualitative topological relationships between geographical objects in a Geographical Pictorial Query Language (GeoPQL) in order to completely capture the semantics of the user queries. We focus on the polygon-polyline topological relation and we define a 16-intersection matrix that has been conceived to enhance and distinguish the semantics of cells’ content with respect to the well-known 9-intersection matrix. On the basis of such distinctions, we revise the geographic operators of GeoPQL and we give their formal semantics. In order to implement our proposed 16-matrix, we invoked in GeoPQL the open source Java libraries JTS Topology Suite, which conforms to the Simple Features Specification for SQL published by the Open GIS Consortium-OGC. Finally, the proposed 16-intersection matrix is illustrated through some query examples.