Upsetting the sedimentary balance of the Sinú delta at Tinajones in the Caribbean Coast of Colombia

Abstract:

Wave-dominated delta morphology results from the balance between river sediment flux and wave energy. Changes to this balance can have drastic effects on delta morphology, including wave reworking and shoreline erosion. Here, we analyze the recent morphological evolution of the Sinú delta at Tinajones, in the Southern Caribbean coast, to illustrate wave reworking from changes to the delta sediment flux balance. During the last decades, the delta at Tinajones has transitioned from having one river-dominated mouth to having three wave-dominated mouths with an overall delta R factor of 2. However, the present-day morphology indicates that a transition to two distributary mouths is occurring due to the closure of one river mouth. Our preliminary results suggest a drastic reduction in riverine sediment flux represented by an overall R factor of 0.8. We identify multiple upstream river diversions as the main potential factor contributing to riverine flux reduction, with current morphology exhibiting the effect of high-angle wave instabilities and likely preferential bypassing. Our results provide preliminary evidence that changes in sedimentary balances at the Sinú delta might impact sediment budgets of adjacent shorelines along the Caribbean coast of Colombia.