Modelling social interactions in volunteered geographic information projects requires defining what binds contributors together. In order to be as realistic as possible, instead of choosing one social aspect to study, we choose to build a multi-layered social network that contains several types of interaction between VGI contributors. The analysis of such a multigraph should allow the detection of communities and the definition of typical profiles of contributors. A use case on OpenStreetMap illustrates what inferences can be made about contributions based on their authors.