Summary:

The paper presents the results of determinations and calculations of bankfull discharge Q_b for two chosen mountainous gravel-bed rivers: the Raba River and the Kamienica River. Also within the paper described in details some main methods of determination and calculation bankfull Q_b: the Williams, the Woodyer, the Wołoszyn, the Riley, the Pickup&Warner, the Wollman and the Warner, Schumm&Browna methods. On the basis of the analysis of obtained results of bankfull value using all applied methods it was pointed that to determine bankfull one does not have to hale the river gauging observations. The data which are enough to calculate/determine Q_b could be collected in-situ just within the research cross-section where there is a need to find bankfull. Another words the river/stream where one plans the hydrotechnic investment or river training works does not to have be hydrologically controlled. At the same time, for the civil engineer designer bankfull value is very important in term showing the real value of the discharge which shapes the river cross section and is responsible for fluvial morphological changes (the dominant discharge). Finally it was pointed that bankfull is responsible for plants species location along the cross section of the river. Because of that, it was suggested that from ecological point of view it would be worthy to determine bankfull using Woodyer method in all cross sections when river training works are planed in the river channel. Also it was suggested that in the future it would be very useful to make a plant-atlas of species which one can find in the river channel shaped by bankfull. Such work would be important in all river renaturisation works. The research described in the present paper was realized in Polish Carpathians within the river channels party chanalised and party being in nature.