Author(s): Mario Oertel

Linked Author(s): Mario Oertel

Keywords: Fishways; Vertical slot fishway; ADV; Hydraulic model;

Abstract: Since most waterways and rivers are anthropogenic modified, fishways are import hydraulic structures to stabilize and regenerate fish populations. Fish cannot migrate due to transverse barriers, thus, fishways enable upstream migration at these barriers. Vertical slot fishways are so-called technical fishways. They consist of a series of pools with sloping bottom. In contrast to pool-weir-fishways, vertical openings covering the entire water column enabling fish and benthos to migrate in-between pools. Vertical slot fishways are investigated since several decades – numerous hydraulic and numeric models were performed. Flow depths and velocities as well as turbulent features were of interest in these studies. But only since approximately 15 years extensive velocity measurements were conducted. Bottom slopes of 5 to 20 % were dominating. Also the data quality was addressed only briefly in respect to the turbulent flow features in the fishway and their influence on the measurement. In respect to that, the vertical slot fishway hydraulics in the herein presented hydraulic model were studied at two different slopes of 2.5 % and 5.0 % and different flow guiding elements. Flow guiding elements which are installed at the cross walls can provide deflection of the flow and therefore influence the passablity of fishways. Flow velocities were measured with an acoustic Doppler velocimeter in at a grid at two levels in two adjacent fishway pools. Herein, the results of the study of mean and turbulent flow characteristics are presented as well as an analysis concerning processing the ADV data.

DOI: https://doi.org/10.3850/38WC092019-0945

Year: 2019