CSDMS 2016 annual meeting poster JaapNienhuis
Predicting coastal deltaic change on a global scale
Andrew Ashton, Woods Hole Oceanographic Institution Woods Hole Massachusetts, United States. aashton@whoi.edu
Albert Kettner, University of Colorado, Boulder Boulder Colorado, United States. kettner@colorado.edu
Douglas Edmonds, Indiana University Bloomington Indiana, United States. edmondsd@indiana.edu
Joel Rowland, Los Alamos National Laboratory Los alamos New Mexico, United States. jrowland@lanl.gov
Tor Törnqvist, Tulane University New Orleans Louisiana, United States. tor@tulane.edu
Abstract:
Coastal deltaic change is expected to be one of the major Earth-surface hazards of the 21st century as deltas around the world face large changes in sediment supply due to river damming, land-use changes, and climate change. We have quantified the effect of waves, tides, and fluvial sediment supply on delta morphology to predict future changes to deltaic coasts. Simple parameterizations and key insights from global wave, tide, and fluvial sediment data have allowed us to make morphologic predictions around the globe for every delta on Earth. We find that without human interference many deltas with decreased sediment loads are expected to be reworked by waves into barrier islands or by tides into alluvial estuaries. Other deltas are projected to experience increased sediment flux, and, in some cases these growing deltas could transition to river-dominated morphologies. This unified, global picture of future deltaic change will aid local management of deltaic areas and also provide opportunities for inclusion of morphologic change into Earth system and climate models.
(A) Predicted morphology of about 14000 deltas/river mouths globally. (B) Location in the Galloway Ternary diagram set by the wave, tide and fluvial sediment fluxes. Color and size indicate the fluvial sediment flux, a proxy for delta area. (C) Number of channels for a selection of the 14000 deltas.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
