EX-AQUA PROJECT: PALAEOHYDROLOGICAL EXTREME EVENTS

Floods and droughts are some of the most serious natural hazards for human societies. In the last decade, the catastrophic effects of these events have attracted the global attention to warrant the assessment of their magnitude and frequency, also in relation with climate change. The quantification of the recurrence time and the magnitude of the catastrophic events is mainly based on direct measures, but these are generally limited to last decades, while palaeohydrological researches can extend the records to centuries and millennia. The evidence of past flood episodes and the timing and magnitude of extreme events can be compared with modern data and provide a significant improvement on flood risk assessment. Moreover, the spatial and temporal distribution of extremes and flooding episodes can help to understand the role of climatic forcing on the occurrence of large events and the overall changes in flooding regimes during late Quaternary. In a stratigraphic and geochronological perspective, the traces of extreme palaeohydrological events can be sometimes followed from alluvial, to deltaic and marine environments, supporting or helping correlations. In the last 20 years research methods and gathering of data related to events or phases of palaeofloods and droughts strongly improved. Some of these phases have been clearly recognized at a Mediterranean scale during Holocene, but differences can be highlighted in sub-regions (Benito et al., 2015). Thus, a standardized methodology for creating and comparing local, regional and continental databases is important. The EX-AQUA “Palaeohydrological extreme events, evidences and archives” is a project sponsored in 2016 by TERPRO commission of INQUA and it aims at gathering data about Quaternary hydrological events, mainly considering the Holocene and with a special focus on the late-Holocene (i.e. about last 5000 years) as this includes historic times for many regions. In a global perspective, this period allow to apply a multidisciplinary approach that takes into account sedimentological, geomorphologic, biological, archaeological and documentary data (e.g. historical and written sources, chronicles). These different sources of information allow to produce high-resolution records of extreme events, which could be used as a standard dataset for comparison with other environmental records. The scientific community involved in EX-AQUA aims at sharing information about palaeohydrological series and the methodology for their investigation in the different continents. For these and other related purposes, the meeting “EX-AQUA 2016: Palaeohydrological extreme events, evidences and archives” will be held in Padova next September, 26-28th. The conference will be followed by a 3-days fieldtrip aimed at discussing methodology and results applied in selected case studies dealing with extreme events in the Venetian-Friulian Plain, the southern Alps, the Classical Karst and Istria Peninsula.