SEDIMENT TRANSPORT MODEL OF THE MADEIRA RIVER USING HEC-RAS FOR WATERWAY DESIGN

Código

PAP003

Autores

Calvin Creech, Ana Luisa N. A. O. Castañon, Renato S. Amorim, Stanford A. Gibson

Tema

PROCESSOS HIDROSSEDIMENTOLÓGICOS E MORFOLÓGICOS: FLUVIAIS, LACUSTRES E COSTEIROS

Resumo

The Madeira River in northwest Brazil is an important waterway for the transport of agricultural commodities. However, sedimentation in the navigation channel reduces navigation reliability during low flows. The limited reliability coupled with an increase for the demand of the waterway has led the Brazilian National Department of Transportation Infrastructure (DNIT) to study alternatives for improving navigation conditions on the Madeira River. A one-dimensional sediment transport model using the Hydrologic Engineering Center - River Analysis System (HEC-RAS) was developed to meet three objectives for this study. These objectives included: 1) establish a baseline condition of the sediment dynamics in the Madeira River; 2) evaluate the impact of regional scale sediment processes and system scale non-stationarity of proposed navigation alternatives; and 3) organize the river data in a quantitative framework to improve the conceptual model of the Madeira morphology and sediment flux. The sediment transport model was developed and calibrated to sediment and geometry data collected for environmental monitoring of the Santo Antônio dam. A decadal, reach scale calibration of dynamic equilibrium conditions was achieved using parameters (bed gradation, upstream boundary sediment loads, etc) within the range of observed conditions. The sediment transport model was then applied to predict the system response associated with proposed navigation alternatives, including dredging and river training structures. System response to river training structure simulations yielded self-scouring depths of over 2 meters, which is sufficient to meet required reliability on the navigation channel in current shoaling locations.