Influence of Hydro-Climatic Variability and Coastal Defense Structures on the Hydro-Sedimentary Dynamics of the Coastlines Adjacent to the River Discharge Zone

The trajectory and deposition of sediment particles in coastal areas, related to changes in the coastline, is influenced by physical aspects such as tides, through the processes of flow, ebb and rise in sea level, hydro-climatic variability of the basins, due to the regime of discharge of rivers, the coastal changes caused by alterations in the sediment supply and by coastal defense structures. The above aspects are conditioned by changes in the climate and anthropic interventions. Understanding how these phenomena interact within the sedimentary dynamics in coastal-estuarine zones and how these determine the evolution and stability of the coastlines, adjacent to the area of ​​high discharge rivers are necessary, given the economic and social importance that represent these areas. Therefore, a holistic approach is required, which includes climatic variability and anthropogenic effects in basins, which are highly productive of sediments. For this, the delta of the Magdalena River and the adjacent coastal zone, at the height of Barranquilla-Colombia, have been selected as a case study; given that the hydro-sedimentary dynamics of the coastal area of ​​this region is dominated by the behavior, which throughout the year presents the Magdalena River, besides, it’s one of the rivers with the highest sediment discharge rate on the ocean (180 million ton / year). The comprehension of all these variables and complexity of the domain of study, requires robust and sufficiently adaptable tools, that allow to reproduce adequately the phenomena that occur in these zones. Therefore, it has been proposed, the implementation of the numerical model "Coastal and Regional Ocean Climate" (CROCO) with 3D approach. First, the wave-averaged hydrodynamics and turbulence on a regional scale, will be adequately resolved, subsequently, a sediment transport model will be coupled, with an increase in the resolution of the numerical grid, in the coastal area under the influence of the discharge from the river; numerical experiments will be carried out considering different particle sizes and alterations in river discharge regimes, as the main source of sediments in this area. In addition, the influence of a coastal defense structure will be spatially and temporally represented, as an obstacle to the dynamics of the sedimentary flow, and a simulation will be developed, without the presence of this structure, to evaluate the hydro-sedimentary behavior of these areas, if they could be restored to their natural conditions.