Banca de DEFESA: Tania Machado da Silva

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Tania Machado da Silva
DATE: 28/04/2023
TIME: 14:00
LOCAL: https://teams.live.com/meet/9360383023396
TITLE:

Physical-behavioral systems as mechanisms to control the movement of ichthyofauna in hydroelectric plants.

KEY WORDS:

Ichthyofauna deterrence; Behavioral barriers; Fish confinement; Behavioral effect; Amazon fish.

PAGES: 93
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Hydroelectric power is considered a renewable and clean source of energy, and is the main source of energy in the Brazilian energy matrix. However, the expansion of the hydroelectric sector in the Amazon region requires a careful assessment of the possible environmental impacts resulting from this activity. During the maintenance of the generating units, the operational maneuver of stopping the turbine can result in low flow, leading to the accumulation of fish inside the suction tube. To minimize confinement and possible risks to the ichthyofauna, several repelling strategies were developed. This study investigated the effects of three fish repelling strategies. The first strategy was the operating procedure developed by the Jirau Hydroelectric Power Plant, which consists of increasing the speed of the hydraulic flow due to the reduction of the discharge area of the suction pipe. The results of the maneuver evaluation indicate an 87% reduction in the movement of the ichthyofauna after the increase in the hydraulic flow. This maintenance procedure, associated with real-time monitoring of the suction tube, has a positive impact on the conservation of the ichthyofauna and on the economic costs of stopping the generating unit. The second strategy evaluated was the operative maneuver of deterring the ichthyofauna by dispersing bubbles. The bubble dispersion procedure was carried out using the compressed air injection system built into the suction tube of the Generating Units at the Jirau HPP, on the Madeira River, Rondônia. The results show a reduction of about 42% in the movement of the ichthyofauna after the bubble dispersion procedure, making it possible to infer a considerable decrease in the confinement of the ichthyofauna in the suction tube. The third strategy investigated was the acoustic barrier. For the development of this method, it was necessary to characterize the aerial and underwater soundscape in the vicinity of the Jirau HPP. The results indicated that the interference of the sounds generated by the plant in the soundscape of the region only occurs in areas very close to it, that is, with little environmental impact. To complement the investigation, tests were carried out at the Jirau Plant spillway to assess the impact of four different noise configurations: pink, thunder, gunshot and one with well-defined tonal components, monitoring fish movement before and during exposure to the sound. The results indicate that all noise settings have the potential to increase fish movement, but with different levels of performance. Sound with tonal components, for example, increased fish movement by 57%, while thunder noise showed a 43% increase, followed by gunshot noise, with a 37% increase, and pink noise, which showed an increase of 29%. In general, the three evaluated strategies proved to be effective in minimizing possible impacts on aquatic fauna arising from hydroelectric power generation in the Amazon region.

BANKING MEMBERS:
Interno - 934.875.257-04 - EDUARDO CYRINO DE OLIVEIRA FILHO - EMB/CENARGEN
Interna - 3049879 - ERINA VITORIO RODRIGUES
Externo à Instituição - FELIPE ANDRÉ DOS SANTOS - UNESP
Presidente - 1644727 - LUIZ FABRICIO ZARA
Externo à Instituição - ÉZIO SARGENTINI JUNIOR - INPA