Past hydrological extreme events in a changing climate

Abstract

Fluvial records contain evidence of past hydrological changes in terms of water/sediment fluxes and extreme hydrological events (floods), which can be linked to Earth's climate variability. Sedimentological records of hydrological extremes can be complemented with historical documentary information and botanical records. In recent years, fluvial and palaeoflood records supported with excellent chronological data have become available for many rivers worldwide, but still regional and global palaeohydrological reconstructions and syntheses have yet to be fully developed. Related to the interpretation of alluvial records, a major recent achievement has been the development of new combined analysis of large radiometrically dated fluvial databases, which allow fluvial activity periods to be more precisely defined and to be characterized in terms of forcing hydrological conditions. The approach also serves for comparison of records of fluvial activity in different countries, regions and sites with a range of climate proxies and, for the more recent record, land-use change indicators. The meta-analyses demonstrate the value of the growing spatial coverage and increasing chronological precision of fluvial archives for reconstructing past hydrological events, as well as for understanding river response to environmental/climate change in the past and the future. This special issue brings together a range of papers that reconstruct regional fluvial chronologies of extreme events based on multiple proxies and documentary information, which evaluate the relationship between river hydrology, climate and atmospheric circulation variability. The research presented in this volume was drawn together within the framework of the INQUA Project 1220 on Hydrological EXtreme Events in Changing Climate (HEX Events), and the 1st Workshop on HEX Events held at Utrecht University on November 29th–30th, 2012.