Plan-View Evolution of Wave-Dominated Deltas
Jaap Nienhuis, Ph.D., 2016
Andrew Ashton, Advisor
Ocean waves are a powerful sediment transport mechanism in the coastal zone. This thesis investigates how waves shape deltaic landforms and how small scale river mouth processes affect large-scale delta morphology. I have developed and applied models of plan-view delta shape and their channel dynamics. Simple parameterizations and key insights from these models have allowed us to transcend spatial scales from river mouths to delta plains and make morphologic predictions around the globe for every delta on Earth. I have applied models of delta morphology to backtrack the late Holocene evolution of the Ebro River delta in Spain and estimate timescales and magnitude of past climate change and human impacts. Currently, many deltas around the world face large sediment deficits because of river damming. I model deltaic response to reductions in sediment load and offer frameworks to predict future deltaic change in these dynamic and threatened coastal regions.