Summary:

Research was carried out in the Kamienica river catchment. This catchment is included into three mesoregions: upper part of the basin - in the Beskid Sądecki, central and lower part of the basin - in the Beskid Niski and the Kotlina Sądecka. Seven floods, which occurred in 1997-2010 in the upper part of the Kamienica catchment, were selected in order to verify the suitability of the NRCS method to calculate the direct runoff. The CN parameter value according to NRCS method was estimated based on the observed phenomena of rainfall-runoff. To follow the aim, the total runoff hydrograph was divided into two parts: groundwater (base) flow and direct runoff. The obtained results confirm the reports of other authors that the CN parameter estimated by empirical study is significantly higher than the theoretical value for normal conditions. Thus, it was concluded that during a drought period or, in a case of normal precipitation, watercourses are supplied by groundwater of the first aquifer. The conducted examinations showed, that in the case of mountain catchments, the use of baseflow as an index of ground moisture to calculate the CN parameter is legitimate. It seems that the degree of catchment moisture is better characterized by the baseflow than by the sum of precipitation preceding the flood, as in this case hydraulic relations of groundwater and surface water, as well as in some sense water retention capacity of the catchment are more completely described.