Data for: The pace of global river meandering influenced by fluvial sediment supply

Meandering rivers move gradually across the floodplains, and this river
movement presents socioeconomic risks along river corridors and regulates
terrestrial biogeochemical cycles. Experimental and field studies suggest
that fluvial sediment supply can exert a primary control on lateral
migration rates of rivers. However, we lack an understanding of the
relative importance of environmental boundary conditions, such as
floodplain vegetation and sediment supply, in setting the pace of river
meandering across different environmental settings. Here, we combine the
analysis of satellite imagery and global-in-scale sediment and water
discharge models to evaluate the controls on lateral migration rates of
139 meandering rivers that span a wide range in size, climate, and bank
vegetation. We show that migration rates normalized by the channel width
monotonically increase with the volumetric sediment flux normalized by the
characteristic size of the river. This relation is consistent across
rivers in vegetated and unvegetated catchments, indicating that enhanced
lateral migration rates in unvegetated basins is likely not only
facilitated by lower bank mechanical strength, but also by higher
normalized sediment supply in ephemeral rivers. Using three case examples,
we also demonstrate that width-normalized meander migration rates respond
to spatial gradients in sediment supply caused by river impoundments,
highlighting the prominent role of sediment supply in setting the pace of
meander migration. Our results suggest that sediment-supply variations
caused by climate, land-cover and land-use changes can lead to predictable
changes in meandering river evolution and ultimately drive architectural
changes in sedimentary stratigraphy.