Comprehensive Numerical Hydraulic Model of the Madeira River

Código

XXIII-SBRH0240

Autores

Renato Souza Amorim, Ana Luisa Nunes de Alencar Osorio, Brian Alberto, Calvin Creech

Tema

03 - Hidráulica

Resumo

The Madeira River is the largest southern tributary of the Amazon River, contributing approximately one seventh of the Amazon River flow and more than half of the total Amazon sediment budget. The Madeira is an important fluvial system for ecological, social, and commercial motivations. To support the commercial navigation sector, two separate one-dimensional numerical hydraulic models of the Madeira River between Porto Velho and the Amazon River were developed. First, a steady flow HEC-RAS hydraulic model was developed for the upper 620 km of the Madeira River (between Porto Velho and Manicoré) to establish a Low Water Reference Plane for defining dredging depths. A second unsteady HEC-RAS hydraulic model was developed between Manicoré and the Amazon River (460 km), where backwater effects of the Amazon River significantly influence stages and the in-channel storage leads to spatial variability in flows that could not be accounted for in a steady-state model alone. Attenuation was found to be localized to in-channel processes and is not significant for off-line side channel lagoons or floodplains under flows up to a 25% annual chance of exceedance (4-year recurrence interval).