Determinação das regiões de passagem de peixes em um modelo físico de MTP tipo ranhura vertical

Abstract

The reservoirs are part of the landscape in most of the basins of Brazil. In many cases, dams can be an ecological barrier that cannot be overcome by some species of fish, especially those that need the freedom of upward movement to reproduce. In an attempt to minimize ecological impacts and try to reduce the barrier created by the buses, it is often chosen to construct a fishway, whose main objective is to allow the fish to ascend or descend, making it possible to migrate the ichthyofauna , mainly the rheophilic, between the downstream and upstream of the dam. However, little is known about the hydraulic parameters inside the tank that are ideal for the passage of fish. Thus, sought to correlate the hydraulic parameters of a vertical slot type tank, simulated from different flow regimes with the preferential regions of passage and rest for two neotropical fish species typical of the São Francisco river basin In this work, observations were made to identify the regions with better conditions of passage and rest, within a physical model of a circular tank that simulates a vertical slot fishway for two neotropical fish species (Mandi and Piau). These species were tested at 3 different flows using electric motors at morning, afternoon and evening to determine their behavior. The parameters of velocity, flow, Reynolds shear stresses and turbulent kinetic energy were also obtained. Piau and Mandi showed a very different behavior due to their anatomical differences. However, the Reynolds shear stresses for the two species were between -6N / m² and 6N / m², turbulent kinetic energy is an important factor in the choice of rest and negotiation points for transposition of the mechanisms. two species sought regions close to zero for rest and to promote passage. Thus, it was observed that the combination of kinetic energy and shear stress may explain the preferential resting regions of the two species tested.