Identifying most relevant controls on catchment hydrological similarity using model transferability – A comprehensive study in Iran

•We evaluate two distinct types of hydrological similarity in this study: (i) the apparent similarity measured by similarity distance based on observable catchments descriptors (CDs) and (ii) behavioral similarity, which is determined by highest-performance of transferred model parameters between gauged donor catchment and ungauged target catchment (best-donor case).•More than 75% of our physically similar catchments have a hydrological similarity.•The climatic (aridity index), topographic (mean elevation), and physiographic (catchment area) properties exert a greater influence on parameter transfer to ungauged catchments than do other CDs.