Meta-analysis of a Holocene C-14 database for the detection of paleohydrological crisis in the Venetian-Friulian Plain (NE Italy)

摘要

The Venetian-Friulian Plain is the northernmost alluvial environment facing the Adriatic Sea and it represents the transition from the Mediterranean domain to the Alps and the temperate regions of central and eastern Europe. The investigated area consists of the alluvial systems of Brenta, Piave and Tagliamento rivers, forming distinct alluvial megafans fed by mountain basins of 1567, 3899 and 2580 km2, respectively. The database of radiocarbon dates related to the Holocene alluvial evolution of the Venetian-Friulian Plain consists of 136 samples, 65 of them classified as change-after dates. We analyzed statistically the database with the aim of detecting periods of enhanced flooding activity. The individual calibration probability intervals of each radiocarbon age were summed, producing a cumulative probability density function (CPDF) plot for each alluvial system and for the whole database. Each change-after CPDF plot has been subtracted to its correspondent CPDF plot of the entire sub-dataset, obtaining a relative cumulative probability function (RCPF) curve.