The Negative Phenomenon of Anthropogenically Induced Hydropeacs – Process and Damage

The dynamics of hydropeaks significantly deviates from the same processes in nature by the short time and the number of events.These hydropeaks do not exceed the range of natural floods however, their frequency impacts environment negatively.This creates entirely new conditions for the riverbed morphology.Banks nearly vertical mainly above 6 m height.Narrow river channel regularly less than 40 m wide.More frequent elevated flows lead to stronger erosion, changes in the riverbed structure, and negative impacts on the river's environment.During a flood, animals seek shelter and when the flow decreases they return to the main channel of the river.This process leads to biological losses of fish, larvae, and eggs and applies to all species inhabiting the river.Every high enough water event is therefore a natural risk.Increasing the frequency of the event increases the likelihood of losses.A series of such events were observed and analysed by numerical modelling.We were able to establish an unprecedented frequency and short event time of the phenomenon as compare to the natural conditions.During the disappearance of the flow, as well in river as in model we found variable, rapidly, repeatedly changing and misleading directions of the water outflow.The humaninduced narrow eroded channel structure proved to be more susceptible to dynamic changes escalating the negative process and has demonstrated by examples of fish population losses.