Hydro-morphodynamic conditions of the lower Magdalena river under extreme flow rates – Case study of the sector between PIMSA port and Port of Barranquilla.

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Humberto Avila, Manuel Alvarado

Tuesday 30 june 2015

9:00 - 9:15h at Oceania (level 0)

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

Parallel session: 4B. Sediment - River

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The hydrodynamic conditions forced by high flow rates during 2010 and 2011, as a result of La Niña phenomenon, caused significant morphological changes in the lower Magdalena river, especially in the sector between Calamar (K115) (downstream of Canal del Dique) and the Port of Barranquilla (K19). Monitoring was conducted for this event, with which was possible to identify the hydraulic and morphological behavior of the river. One of the most significant morphological changes occurred in the area between the PIMSA port (K38) (close to Cabica Island) and the Port of Barranquilla (K19) (close to Rondon Island). The flow rate at the Magdalena river during this event was 15,640 m3 / s, downstream after the derivation of the the Canal del Dique, when the historical recorded peak flow was 13,500 m3/s at that time. Additionally, the high flow conditions were maintained for about six months, causing rapid morphological changes that put at risk the infrastructure located on the banks of the river. Several morphological changes occurred in this sector such as the bank erosion at an average rate of up to 3 m/day during 82 days, changes in the distribution of flow rate through the branches of the Cabica Island, and erosion of the Rondon Island, which has an important influence on the navigability conditions on the Port of Barranquilla. The evaluation of these conditions includes the hydrological extreme event analysis, the morphological evaluation, and modeling of the hydrodynamics, sediment transport and morphodynamic conditions. This study represents a significant contribution on the understanding of morphodynamic changes during high flow rates and to the morphological risk assessment in the Magdalena River.