damage. Results of the hydrogeological surveys and the speleological and geomorphological fiedwork. Discussion about this hypogene karst, completely invisible at the surface, making up extremely dangerous situations.
[b2] Italian Inst. of Speleology, Dip. di Scienze della Terra e Geologico-Ambientali, Bologna, Italie
[a1] Dep. of Earth Sciences and Environmental Geology, Italian Inst. of Speleology, Univ., Bologna, Italie