The dataset consists of a GIS vector layer of the contours of 24,148 elementary catchments in Europe and the associated representation of the streamflow regime in terms of empirical flow–duration curves (FDCs). FDCs are estimated by means of the geostatistical procedure termed total negative deviation top-kriging (TNDTK), starting from the empirical FDCs available for 2484 discharge measurement stations across Europe. Together with the estimated FDCs' percentiles, for each catchment, indicators of the accuracy and reliability of the performed large-scale geostatistical prediction are provided. The file is stored using the ESRI Shapefile format in the ETRS89 (European Terrestrial Reference System 1989) – LAEA (Lambert Azimuthal Equal Area) datum and geographic coordinate system.

The compressed .zip folder contains a GIS vector layer of the contours of 24,148 elementary catchments over Europe, stored using the ESRI Shapefile format in the ETRS89 (European Terrestrial Reference System 1989) – LAEA (Lambert Azimuthal Equal Area) datum and geographic coordinate system. For each elementary catchment, the following information is provided:• HydroID: identification code;• NextDownID: ID code associated with the elementary catchment located immediately downstream of the selected one (it is set to -1 if no elementary catchment is present downstream within the GIS layer);• Area_EC: area of the elementary catchment (km²);• Area_AC: drainage area of the whole catchment (km²; for headwater catchments, Area_AC=Area_EC);• Gauged: distinguishes between gauged and ungauged nodes: “yes” for gauged catchments (i.e. 2484 catchments with high-quality data); “no” for ungauged catchments (i.e. 21,664 prediction nodes);• Var_est: prediction variance for each elementary catchment (-);• TND: empirical value of the total negative deviation (TND; see e.g. Pugliese et al., 2014) (-).• MAF: Mean Annual Flow (m³ s⁻¹) (if the field “Gauged” is equal to “yes”, then the values are empirical, while they are predicted otherwise).• from D9Q1 to D9Q997: FDCs' streamflow percentiles (m³ s⁻¹); 15 values from 1st to 99.7th (if the field “Gauged” is equal to “yes”, then the values are empirical, while they are predicted otherwise);• LNSE: logarithmic Nash and Sutcliffe Efficiency values obtained in leave-one-out cross-validation (LOOCV) for gauged catchments; for ungauged catchments, the distinction is made between catchments having prediction variance lower (“yes”) and higher than KV* (“no”). No values are reported for those gauged catchments where the presence of measured percentiles of daily flows equal to zero makes the evaluation of LNSE not possible;• LakeRatio: ratio between area covered with bodies of water and total area for each elementary catchment (-);