The effect of moisture conditions on estimation of the CN parameter value in the mountain catchment

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 ...

Flood retention capabilities in a mountain catchments: case study of the Commune of Spytkowice

The experience of flooding from 2010 in the Commune of Spytkowice showed a dire need to define the factors behind the floods repeating every year in the region and to propose the best solutions for eliminating or limiting damage in the risk area. On account of the catchment's location in mountainous area, the main intention was to propose actions that would mainly increase the catchment retention capacity in the upper reach of the Skawa river and its tributary, Pożoga. By slowing down the flow, these actions may considerably contribute to the protection of the most flood-sensitive areas located in the lower part of the catchment. Two solutions have been proposed based on the idea of building dry water reservoirs and providing the possibility to resettle inhabitants from the flooded area. The choice of the best solution for the Commune of Spytkowice depends on the topography of the valleys of rivers Skawa and Pożoga, as well as the financial situation concerning the project. ...