Produção Nacional
Avaliação das modificações hidrológicas ocorridas na Estação de Porto São José, situada em um trecho do rio Paraná regulado por Usinas Hidrelétricas
2015; Brazilian Association of Water Resources; Volume: 20; Issue: 3 Linguagem: Inglês
10.21168/rbrh.v20n3.p752-762
ISSN2318-0331
AutoresLuiz Henrique Maldonado, Paulo E. Gamaro, Jéssica Santos,
Tópico(s)Fish Ecology and Management Studies
ResumoHydroelectric Plants (UHE- Usinas Hidroeletricas) are importantly represented on the Brazilian energy scene, and provide the base for the National Interconnected System (SIN Sistema Interligado Nacional). However, one of the consequences of UHE operation is changes in the natural hydrological regimes of the river system both upstream and downstream from the dam. For this reason this paper analyzes the possible hydrological changes at a rivergauging station downstream from a hydropower plant, based on field campaigns with flow measurements carried out during the period from 1965 to 2014, bathymetric surveys and historical series of water levels The results obtained for Porto Sao Jose Station (PSJ) in Parana river, 30 km downstream from UJE Porto Primavera and UHE Rosana, indicate the occurrence of erosion in the PSJ section with a 28% increase in the wetted area and 20% reduction of mean velocity. Because of these changes a new rating curve was determined for the permanent flow condition, and the non-permanent flow condition (hysteresis) was identified and corrected for PSJ. Thus, taking the sum total of outflows from the UHEs as reference, the calibration table indicates monthly deviations of -500 m3 s-1, the rating curve for permanent flow deviations of - 90 m3 s-1, and the rating curve for non permanent flows deviations of -75 m3 s-1. Although the rating curve for permanent flows presents small monthly deviations (- 90 m3 s-1), because of the daily energy demands, the outflows from the UHE cause hourly deviations at PSJ of +640 to -610 m3 s-1 (mean of 17 m3 s-1). Thus flow regulation in this reach of Parana River caused alterations of hydrological and hydraulic variables at PSJ (e.g. area, velocity, runoff for non-permanent condition) which could be correctly represented by rating curves defined by continuous field campaigns
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