| dc.description.abstract | Crevasse splays are landforms created by breaching of river levees and are part of many large river systems
over the world. Due to potentially high aggradation rates, they can be effective tools against relative sea
level rise. Here we describe a combined field- and modeling effort, in which we assessed the effects of
floodplain drainage on crevasse splay development. By mapping crevasse splays for the Rhine-Meuse- and
Mississippi Deltas and linking it to floodplain size, we investigated the effect of the floodplain on crevasse
formation. We used the morphodynamic model Delft3D-FLOW to test results found in the field. We found
that the largest floodplains accommodate the largest crevasse splays. This was confirmed by our model
simulations, in which simulations with large floodplains have slowly rising water levels, keeping lateral
surface slopes high which ultimately result in large flow velocities and rapid crevasse growth. Additionally,
we found that small flood durations increase erosion and thus further aid this effect. The combined effect of
flood duration and floodplain size were combined into a parameter, which was proven to accurately predict
crevasse growth in the model and allows for a first order comparison with field data. The conclusions drawn
from this research increase our understanding in crevasse growth and my help in future restoration projects
that involve artificial levee breaching | |
