Effects of Sandbank Vegetation on Riverbed Variation and Change of Bed-Surface Grain Size Distribution During a Largest Flood

Key Points

• This research examines how vegetation in riverbeds affects sediment dynamics and grain size distribution during flooding events.
• Conducted two-dimensional riverbed variation calculations and field surveys.
• Used UAV photogrammetry to obtain vegetation height distribution data.
• Directly sampled sediment grain size distribution for validation of calculations.
• Analyzed vegetation resistance to interpret riverbed dynamics during floods.
• Vegetation resistance significantly influences riverbed change during peak flood events.
• Grain size distribution continues to shift during lower flood flow periods.
• Essential to extend evaluation periods to include post-flood dynamics when assessing sediment transport.