The strength of GIS is in providing a rich data infrastructure for combining disparate data in meaningful ways by using a spatial arrangement (e.g., proximity). As a toolbox, a GIS allows planners to perform spatial analysis using geo-processing functions such as map overlay, connectivity measurements or thematic map coloring. Although, this makes effective the geographic visualization of individual variables, complex multi-variate dependencies are easily overlooked. The required step to take GIS beyond a tool for automating cartography is to incorporate the ability of analyzing and condensing a large number of geo-referenced variables into a single forecast or score. This is where data mining promises great potential benefits and the reason why there is such a hand-in-glove fit between GIS and data mining. Following the mainstream of this research, we propose to integrate GIS and data mining functionality in a closely coupled open and extensible GIS architecture. This is done by re...