Zum Fischschutz und Fischabstieg an geneigten und horizontalen Rechen

Based on experimental investigations offish behaviour at inclined and horizontal screens, the guidance effects toward the bypass and the resulting efficiency offish protection and fish downstream passage of such approaches were assessed. Low slopped screens with small bar clearance and horizontal screens with low approach flow velocities featured high efficiency when combined with adequate bypass entrances, even for small fish and weak swimmers. In turn, steep screen inclinations, large bar clearance or unsuitable bypass arrangements disable guidance and can entail fish damage at the screen. The deduced modelling of bypass passage partitions provides comprehensive relations of guidance and underlying design parameters and shows good accordance for exemplary field references.