ORGANIZATION OF FISH MIGRATION CYCLE WITHIN FISH-PROTECTIVE CONSTRUCTION OF HYDROELECTRIC COMPLEX

Abstract

Introduction. Water engineering on the rivers and inland water reservoirs almost completely disturbs the conditions for fish migration. Spawing migration against the flow is stopped by the dams, which leads to termination of natural reproduction and downstream migration is resulted in fish kill  in the turbines of hydro-electric power stations and water reservoirs. Besides, feeding migration is also reduced, nonmigratory  fish form 2 schools instead of one — one school is formed higher the dam, another one – lower the dam. The goal of the research is to elaborate the activities to organize fish migration cycle in fish-protective constructions of  hydroelectric complexes. The following task was set for it: significantly improve the efficiency of work of fish passing constructions and fish-directing devices, assuring   downstream, spawing  and other types of migration through the hydroelectric complexes  regardless of the pressure on the dam of  hydroelectric complexes. It is possible to find the solution of the task at hand in further improvement of the construction of classical fish-ways (they should be more simple in construction and  similar  to the natural conditions of fish habitat as high as possible) . The applied for these purposes technology (usage of hydraulic jets) will let to modernize the constructions of the classical fish-ways both to efficiently pass the fish in spawning season   through the dams of  hydroelectric complexes and to perform high-productive  downstream migration. The offered engineering solutions. Hydraulic jets make it possible to correct cross current in the fish-passing outlets of the fish-passing construction. In this case there is a possibility both to improve the efficiency of  functioning of fish-passing constructions in the period of  spawing migration  and to use the fish-ways at the high-head water development and to apply the data of fish-passing construction  in conditions of these hydroelectric complexes for return of fish and young fish. Besides, hydraulic jets make it possible to direct and  redirect migrant fish and young fish in the desirable place of the  reservoir, saving naturalness of  habitat. Experimental researches. Possibility to use of the offered mathematical model and engineering solutions in practice to restore fish migration cycle in the regulated rivers was experimentally conducted on the example of the laboratory model ( scale). In course of carrying out of the laboratory researches, Froude similarity criterion was chosen as the basic criteria of hydrodynamic similarity. Conclusion. The offered engineering solutions and technologies in organization of fish migration cycle, including fish-protective constructions of  hydroelectric complex, make it possible to get closer to solution of the key problems to  renew natural reproduction of many kinds of fishes in the regulated rivers. The offering engineering solutions and technologies, supplementing and enhancing fish-protective constructions, improve their efficiency. The described in the paper  technology will allow to use the fish passing constructions on  the hydraulic jets to assure spawing and down stream migration which is very economically sound. Distinctive features of the offered element of this construction is flexibility of control of the constructions and compliance of them with ecological requirements.