Hydrodinamic and sediment transport modeling in a bend of Napo amazonian river : morphodynamics and infraestructure implications.

Julio Isaac Montenegro Gambini

Tuesday 30 june 2015

17:51 - 17:54h at Oceania (level 0)

Themes: (T) Sediment management and morphodynamics, (ST) River morphodynamics, Poster pitches

Parallel session: Poster pitches: 7B. Sediment - River

This research aims to evaluate the hydraulic properties and processes of erosion and sedimentation using a Bidimensional model to study the river and sediment behavior as on a meander of Napo River in the Peruvian Amazon. We have used Teledetection techniques to assess plain morphodynamics and geomorphology implications, recognizing some chute cut-offs that affects flow and working as shortcuts between two points using a straighter alignment and implies a reduction in the length, increasing slopes. This will lead to a tendency to stream erosion. Napo River and the confluence with Mazan River, a tributary in the study site, apparently has no influence on the site and can be indifferent today. However with this time analysis and modeling, some changes will be denoted in the bed and we will be are able to note concentration of erosive velocities and specific discharges very near the Mazán Port, a infrastructure in the right bank of Napo River. During this work are denoted changes in the bed and the concentration of erosive velocities and shear stresses that affects a short transit to the confluence zone (Napo-Mazán) and its effect on the sediment bed and suspended load transport extending us a couple of kilometers upstream and downstream to see potential impacts. To reassess these processes, we applied CCHE2D model based on equilibrium bed load transport of uniform and no-uniform materials, it was calibrated using the daily measurement campaigns carried out in the studied site, furthermore size distribution of sediments was obtained by laboratory tests of field cohesive and non-cohesive samples in order to obtain settling velocities to set the model parameters. Once we had obtained qualitatively consistent results, it is necessary to restore river banks with help of transport of solids of the Napo River and return the island in its initial condition, proposing solutions such as pile driving around the initial perimeter and in the area eroded to set an fluvial equilibrium.