gvSIG-Desktop 1.12. User manual

This geoprocess only acts on one “input layer”. The process analyses each entity in the "input layer" and merges the elements that have an identical value for a specific field into one element. Moreover, it allows you to involve spatial criteria in the decision to merge several features. This allows you to establish that for two elements to be merged, they must be adjacent to each other in addition to having the same value in the specified attribute.

Example: We have a polygon layer which represents the municipalities of a particular autonomous region and we need a polygon layer with the provinces which make up this region. We can generate a province layer by launching the “Dissolve” geoprocess and specifying that the polygons that have the same value for the "PROV" field in which a unique code for the province is specified are merged.