Relative role of marine and riverine sediment transport in morphodynamics of tropical river deltas in Colombia

Tropical deltas along the Caribbean and Pacific coasts of Colombia, exhibit catchment conditions that include very high denudation rates, high relief, and environmental degradation linked to land-use change. Here we apply a predictive framework to assess the potential response of deltas to expected intensification of human land use. We apply this framework to 99 Colombian deltas by quantifying a balance between sediment transport by river, wave, and tidal processes at their mouths. We calibrate this sediment transport balance through comparison with observed morphology to improve our predictions of future change. We find that most Colombian deltas are wave dominated, with the exception of large catchments with high riverine sediment load that are river- and tide-dominated. With increased sediment loads resulting from land-use change, we predict many of these deltas to become more river and tide-dominated