Acta Scientiarum Polonorum

General remarks on river regime flows are presented, the processes observed in the river channels (within
the area of river flood embankments) are described. The engineer’s attention is diverted for necessity of
elaboration the definite evaluation of geomorphological transformations of river channels in the past and
their influence on the water levels elevations for Design Floods as the function of time during exploitation
period. The author’s method for evaluation of water levels (and discharges) instability as the function of time
is described. New definition for “instability factor” has been introduced for water levels and discharges. The
dynamic hydrology concept approach has been applied e.g. the channel water levels (H) and discharges (Q)
are presented and discussed in historical perspective.