Water management and land use in the terramare and a possible climatic co-factor in their abandonment : The case study of the terramara of Poviglio Santa Rosa (northern Italy)

The terramare, archaeological sites generated by a civilisation which settled the centre of the Po plain since the Middle Bronze age, were abruptly abandoned at the end of the Recent Bronze age. The reason for this abandonment is still a matter of debate. In the context of a multi-causal explanation, this paper discusses a possible climatic factor, inferred from recent discoveries at the site of Poviglio Santa Rosa (northern Italy). The culture of the terramare produced a systematic and intensive agricultural and pastoral exploitation of the environment and caused heavy deforestation. Water was a critical resource and was carefully managed. The moat which typically surrounded most of the sites was meant to concentrate and redistribute water to the fields through a network of irrigation ditches. The study of the water wells discovered at the fringe of the terramara of Santa Rosa reveals a drop in the water table during the late Recent Bronze age, caused by a dry event of regional relevance. Chronological contiguity, supported by the archaeological context between this occurrence and the abandonment of the terramare system, strongly suggests a causative link between the two events. The climatic event, a minor episode in the history of the Holocene climate, nevertheless acted as a catalyst in a stressed environment whose resources were over-exploited by rising demographic pressure.