Interpretation of large data sets is a challenging but often rewarding approach to understanding key controls on system behaviour. Top-down analytic approaches informed by (typically simple) system conceptualisations, as exemplified by the Budyko style water balance modelling, are often highly valuable in assisting such interpretations. Authors are invited to submit papers on data-oriented modelling frameworks designed to identify catchment system characteristics from flow, groundwater, water quality and other catchment data sets.