Edna Maria de Faria Viana

Optimal swim speeds by respirometer: an analysis of three neotropical species

The swimming ability of neotropical fish species is an important aspect for fish ladder designs. Especially in Latin America, where fish ladders are highly selective, fish strategies to negotiate the passage should be studied focusing on target species. This paper shows the swimming ability of three neotropical species (Leporinus reinhardti, Pimelodus maculatus and Prochilodus costatus), from Sao Francisco river basin. Respirometer was employed for data collection. Regarding the critical and prolonged speeds, L. reinhardti was the fastest among the three neotropical species in relative values (body length/second). The performance of neotropical species was better when compared to critical and maximum prolonged speeds of fish species from temperate areas. Finally, regarding the experimental procedures, the optimization of swimming speed in respirometer is lower than the optimal processes obtained with free swimming in open channels.

Analysis of the hydraulic behavior of a vertical slot fishway in two slopes

ABSTRACT Several fish transposition systems (MTP´s) have been employed to allow the fish upstream migration through river dams for spawning. The design of MTP´s of the type of vertical slot fishways requires not only the analysis of the pool hydraulic behavior to evaluate the velocity fields, the energy dissipation levels, and the Reynolds shear stress distributions, but also the study of biological characteristics of aquatic species impacted by the river dams. However, these parameters are not evaluated together, and some of them are valued at the average of the tank. This work deals with an analysis of the main hydraulic characteristics of a slot vertical fishway at two channel slopes, 6% and 12%. The hydraulic characteristic graphs obtained in this work show that a slope of 6% is preferable for the design of this kind of fishway, since the associated velocity magnitudes fits better to the ideal conditions for the safe fish passage. The slope of 12% creates restrictions in terms of the available area for fish passage due to power dissipation and shear stresses conditions.

Reduced hydraulic model of Forquilha IV tailings dam

This paper presents the development of a reduced hydraulic model (RHM) for the outflow operating system at the Forquilha IV (scale 1:10) tailings dam, owned by Vale S.A. The studies were performed by Centro de Pesquisas Hidraulicas e Recursos Hidricos (CPH) of Universidade Federal de Minas Gerais (UFMG) and the company Vogbr Recursos Hidricos & Geotecnia Ltda. We present here a brief description of the model construction and the test battery set for the structure’s hydraulic analysis. RHM involves the hillside culvert, the dissipation box and the exit to the restitution tunnel. The RHM project represents an essential step in the first analysis of the hydraulic behavior of the prototype, considering the designed flood station (ten thousand-year flood flow), as well as the analysis of its operation with more frequent flows.