ISBN : 978-3-642-03612-5International audienceThis paper revisits the construction of watershed and waterfall hierarchies through a thorough analysis of Boruvka's algorithms for constructing minimum spanning trees of edge weighted graphs. In the case where the watershed of a node weighted graph is to be constructed, we propose a distribution of weights on the edges, so that the waterfall extraction on the edge weighted graph becomes equivalent with the watershed extraction on the node weighted graph