Morphological behavior of the Magdalena River delta (Colombia) due to intra and interannual variations in river discharge

Abstract

Morphological conditions of river deltas define the sedimentological processes of this kind of ecosystem, which are strategic points to locate transport infrastructures, such as ports. River deltas can present morphological variations caused by natural or anthropogenic factors, affecting the navigability conditions of cargo ships. In order to guarantee feasible conditions for the navigability of river deltas and reduce economic costs caused by dredging activities, further studies are required to assess the relationship between hydrological and hydrodynamic processes with the morphodynamic behavior along the river basin. This study evaluates the hydrodynamic and morphodynamic conditions of the Magdalena River delta (Colombia) based on river discharges, water levels, and bathymetric information for the period 2006–2012. Moreover, linear-time-invariant systems (LTI) was developed to perform correlation analysis between the climatic oscillations, such as the ENSO, and the water level conditions in the Magdalena River. The bathymetric analysis showed unsteady morphological conditions along the river bed and high erosion rates during the studied period. The delta presented sedimentation conditions during El Niño years, or periods with negative discharge anomalies, and erosion rates during La Niña years, or periods with positive discharge anomalies. For intrannual scales, dry periods (January–April) presented sedimentation trends, whereas wet periods (September–December) exhibited significant erosion trends.