A friend gave pointed out to me this morning this map of hydrogeological hazards in Italy, as produced by the local authorities and collected by the Italian Ministry of Italy. The full map at higher resolution (1.4 Mb) can be retrieved here (I think it is public and can be found somewhere in the Environmental Ministry of Italy). "Carta delle aree ad alta criticita' idrogeologica" means: maps of the area with the highest potential hazards. Red are landslides, blue are flooding, green snow avalanches hazards.
Why these differences ? Different techniques of mapping ? Different "political choices" ? Different stage of production of the maps (did all really made it) ?
Who knows can give me a clue ?