Geo-SOM and its integration with geographic information systems

Abstract – Clustering geographically referenced data is an important issue in Geographic Information Science. Although the standard SOM can be used in many of these problems, it is useful to have a clustering tool that takes into account the special importance that geographic location has in these problems. In this paper, such a tool, named GEO-SOM, is presented. The differences between the training and mapping algorithms of the standard SOM and GEO-SOM are pointed out, and some simple examples of applications are given. Another important issue in the analysis of geo-referenced data is visualization of results, and integration with well established Geographic Information Systems (GIS). It is shown that GEO-SOM can easily be integrated in such systems, and examples of relevant visualization tools are presented. The fundamental assumption of the GEO-SOM is that some variables (in this case geographical coordinates) are more important, in the sense that they condition any subsequent clustering