Holocene geomorphic activity related to climatic change and human impact in Basilicata, Southern Italy

A critical analysis of 34 radiocarbon dates, selected from a total of 42 published and unpublished dates from Holocene fluvial environments in Basilicata (southern Italy), has identified eight periods of increased fluvial activity in this area, namely: 7200–6800; 4800–4550; 4300–4100; 3400–3100; 2350–1850; 1700–1320; 1050–800 and 300–120 cal years BP. Many of these phases coincide with the main flooding events recorded elsewhere in the Mediterranean. The record is discussed in relation to high-resolution central-southern Italy pollen and lake level records and Alps and Apennine (central Italy) glacier variations to identify relationships between geomorphic activity and Holocene environmental change. The data comparison suggests that aggradational and incisional episodes were primarily climatically driven, whereas flooding coincided with colder and moister phases, while incision (i.e. gully formation) occurred during dry-warm periods due to high magnitude, low frequency alluvial events. Phases of widespread fine-grained aggradation occurred in the last 2000 years, also suggesting that anthropogenic impact has intensified these processes, adding its effects to the climate impact.