Past hydrological extreme events in a changing climate

This paper describes developments in the analysis and interpretation of Holocene fluvial chronologies over the past 25 years. Particular consideration is given to meta-analysis approaches pioneered by Macklin and Lewin (2003), using radiocarbon-dated fluvial deposits in Britain, which have transformed fluvial geochronologies and correlations with climate and land-use records worldwide. During the last decade methodological developments have addressed issues such as correction for the shape of the radiocarbon calibration curve in the probability analysis of dated fluvial units and for variable alluvial unit preservation. The number of regional database analyses of fluvial sedimentary archives has also expanded significantly during the past decade, with studies now available for Africa, the Mediterranean region, India, Ireland, New Zealand, Poland, the Rhine catchment and the UK. Methods for incorporating optically stimulated luminescence ages in the probability analysis have also been developed and are illustrated using the database of Eastern Mediterranean dated fluvial deposits. There is considerable potential for meta-analysis research to inform long-term flood risk assessment, to evaluate short-term climate and land-use change impacts on flooding and river behaviour, and to test landscape evolution models