Regional Prediction of Hydrological Extremes at Ungauged Sites (Sessione HS47 nell'ambito della 2006 EGU General Assembly)

A large group of researchers and hydrologists from all around the world is dedicating a great deal of attention to the problem of predictions in ungauged basins. Evidence of the liveliness of this research sector can be found in the initiative titled: Decade on Prediction in Ungauged Basins (PUB), a wide research project promoted by the International Association of Hydrological Sciences (IAHS) [e.g., Sivapalan et al., Hydrol. Sci. J., 48(6), 2003]. A fundamental branch of this broad topic is represented by the estimation of design events at ungauged sites. There is a general consensus among researchers that Regional Frequency Analysis (RFA) of hydrological extremes (i.e., flood flows, droughts and rainstorms) represents one of the most viable approaches for pursuing this task. Among the most interesting issues concerning RFA of hydrological extremes, the scientific literature points out several priority problems, three of which are specifically addressed by the present session: i) development of objective and process-based classification criteria (or pooling techniques) to form hydrologically homogeneous pooling groups of sites (i.e., catchments for regional frequency analysis of floods and low-flows; raingauges for regional frequency analysis of rainstorms); ii) identification of effective procedures for testing the homogeneity of pooling groups; iii) assessment of the impact of intersite correlation on the information content of regional samples and uncertainty associated with regional estimates. Contributions addressing one or more of these points are welcome. Session format: Poster session introduced by a compact oral session including a few solicited contributions addressing the session's keynotes (30 min. each), a series of short oral presentations of posters (5 min. each), and an open discussion.