Resumen
In this study, the river system and the surface drainage system (SDS) operating during heavy rainfall in two Carpathian catchments located in foothills and medium-high mountain areas were compared. The results revealed that regardless of the differences in the river systems and physiographical parameters of the catchments, the SDS operating during heavy rainfall becomes similar. This similarity is reflected in the density of the SDS (11.5?12.2 km·km-2) and the structure of the SDS, confirmed by Hortonian-type analysis. This similarity in the SDS was discussed in the context of the geomorphological transformation of the hillslopes and the hydrological response of a catchment to heavy rainfall.