Holocene environmental changes and their impact on anthropogenic activity: Some examples from Italy

Geological and archaeological evidence in Italy indicates that in the pre-historical and historical times men and their activities suffered from deep environmental changes, caused by natural processes acting at different time scale. Long-term modifications were induced by fluvio-de ltaic processes, which acted over decades or centuries and strongly modified the morphological aspects of coastal zones, causing the filling in of wide lagoons and the seaward shifting of the shorelines. The delta areas of rivers Ombrone (Tuscany) and Tevere (Latium) are examined. Geomorphological evidence testifies that the environmental modifications of the two areas were almost isochronous and they occurred gradually in time intervals of some decades up to some centuries. Contemporary, archaeological studies show that human settlements had time enough to conform their structures and economies to the progressive and slow environmental changes. Sudden changes occurred because of volcanism; some evidence of this kind of modifications are found in the volcanic area of Somma-Vesuvio (Campania) where catastrophic eruptions caused huge topographic variations over the last 3500 years and the destruction of human settlements. Unlike the delta areas, in the Somma-Vesuvio neighbouring the morphotopographic modifications were so fast and drastic that people could not conform their activities to the changed environmental conditions. However the cited examples indicate that, although repeatedly and deeply modified, this volcanic area never stopped attracting people because of the large availability of environmental resources. This is proved by the examined archaeological sites, where the remains of stable settlements alternate with eruptive or volcanoclastic deposits.