The aim of the research was to develop a methodology for the hydraulic calculation of fish-spawning canals with elements of enhanced roughness. New approaches to the hydraulic calculation of fish-spawning canals, arranged in the structure of low-pressure river hydroelectric complexes, are considered. Observance of the corresponding values of current velocities will create favorable conditions for passage and spawning of various species of fish in the trails of such channels. To reduce the current velocities and create multi-speed regimes in the fish spawning canals, it is proposed to use a combined channel roughness including gravel-pebble cover on the bottom and slopes, as well as separately standing elements in the form of concrete cubes, which are elements of artificial roughness, as separate hydraulic resistance generators. The hydraulic calculation of the fish spawning channel is based on the determination of the reduced roughness coefficient of the gravel-pebble material and the roughness coefficient of the entire combined coating, taking into account the protruding elements in the form of concrete cubes uniformly located along the bottom of the channel in staggered order. On the basis of the foregoing the methodology of hydraulic calculation of the fish spawning canal was proposed and approved and a program for electronic computers in the programming environment MathCAD was developed for further calculations simplification and its application. The results of calculation of the quantitative parameters of the fish spawning canal are given (canal length is 7600 m, canal width is 36.0 m, water depth is 2.5 m, canal flow is 100 m cubic per second, average speed is 0.9 meters per second, canal slope is 1:3.5, roughness coefficient is 0.0436) and conclusions were drawn on the materials of the conducted research work.
Key words: fish-spawning canal, roughness, hydraulic calculation, elements of increased roughness, multi-speed regime.
