ROCK RAMP IMPACT ON THE RIVERINE HYDRAULIC

The following case study is part of a wider research of the impact of rock ramps on river environment. It aims to give a quantitative assessment of the velocity reduction in upstream section of a rock ramp. The alteration of the flow velocities is one of the most considerable factors for the habitat modification. The creation of still water environment in upstream impoundment might affect the physical properties of the habitat. Thus a mutation of the hydrobionts diversity may occur. By means of one – dimensional numerical model а comparative analysis of velocity fields is executed. Two cases are examined: before and after construction of a rock ramp with step – pools. The model proofs a significant flow velocity reduction in upstream section, which might have a negative environmental impact.Another point of interests of the study is the high flow river capacity. The flooded areas and the water level variation are evaluated at Q50%, Q5% and Q1%. The results can be used for assessment of the structure reliability and for analysis of both: saturation of riparian zone and alteration of floodplain ecology