Automatic classification of relief attributes into meaningful morphological units has a great potential within the field of geomorphology. When applying common classification algorithms such an iterative cluster analysis to relief data, the result is often a set of classes with a marked lack of coherence in geographical space. The scattering of classes occurs because there is an authentic overlap between different classes in both attribute and geographical space. Therefore other procedures should be used for relief structuring that take the class overlap into account. Such a procedure could be the application of a contextual merging, or generalisation, prior to classification. As a case study, an area close to Ny-