Objective and process-based catchment classification as a tool for prediction in ungauged basins

Event Information Researchers from all around the world are putting a great deal of effort into the problem of streamflow Predictions in Ungauged Basins [PUB, an IAHS initiative e.g., external link: http://pub.iwmi.org]. This session originates directly from research activities carried out under the PUB initiative and aims at stimulating the discussion on how catchment classification can help in various instances of streamflow prediction and on how objective and process-based criteria can be developed for this. In particular, the attention is focused on three different aspects i) development of new insights regarding the role of catchment similarities in the explanation of regional hydrological patterns; ii) reconsideration of the 'pooling' concept in the context of hydrologically homogeneous groups of sites, and iii) analysis of possible common 'dominant processes' as a basis for new paradigms of similarity. Original contributions are solicited that address the investigation of similarities among catchment characteristics and processes. Further specific topics that can be of interest are: a) analytical and experimental investigation of basic processes that govern the overall catchment short-term and long-term catchment behaviour (e.g., relevance, size and characteristic time scales of the 'water storage' factors); b) statistical tools that aim at enhancing the role of catchment descriptors in regional frequency analysis of characteristic streamflows, c) usefulness of climatological classification for streamflow prediction in ungauged catchments. Finally, the session will also serve as an open forum for hydrologists and researchers to present and discuss the latest results achieved through the PUB-driven initiatives related to the session topic that are currently active worldwide. Preliminary List of Solicited Speakers Günter Blöschl (PUB Chair) Co-Sponsorshi