Hydraulik der Schlitzöffnungen bei beckenartigen Fischaufstiegsanlagen

Hydraulics of vertical slots in fish passes

The passage of fish of artificial obstructions (e. g. weirs, dams) is explicitly demanded by the EU-Water Framework Directive in order to achieve good biological connectivity and therefore good conditions for the concerned water bodies. The usage of fish passes with tanks and slots (e. g. classic vertical-slot-pass, meander-type fish pass) is a possible solution. This design variant of fish ladders is characterised by at least one continuous slot in a divide wall between two neighbouring tanks. The paper offers a discussion about the design criteria and the essential hydraulic characteristics. Thereby the slot-opening sector represents the centrepiece. Simplified and universally applicable approaches for determining the significant flow velocities and discharges are proposed. It needs to be noted that the flow in a slot can be handled as the combined result of overfall and lateral outlet.