Table 2. Summary of the cluster groups obtained by training self-organizing maps (SOM) using the hydrological indices selected for the non-permanent Mediterranean rivers. The mean, standard deviation, coefficient of variation and interquartile range are included of number of days per year without flow (DU035, in days/year), annual percentage of months without flow (FE052, in %), mean daily annual flows (MA001, in l/day), CV of Julian date of the annual start of zero flow (TI002) and annual rise rate (RC001, in l/day).