![meander bends meander bends](https://thumbs.dreamstime.com/b/horseshoe-bend-shaped-incised-meander-colorado-river-located-near-town-page-arizona-140447246.jpg)
An exciting new geomorphic discovery emerges from the analysis revealing the role of cutoffs as drivers of nonlocal morphodynamic change. Analysis of the resulting annual binary channel masks suggests that migration rates are controlled by processes acting across bend-to-reach scales. Lateral channel migration and point bar formation (meandering) occur as a secondary process that does not change the shape or width of the bar fingers.
![meander bends meander bends](https://image1.slideserve.com/2750884/slide5-l.jpg)
This research mines the vault of Landsat imagery to resolve over 30 years of planform migration along more than 1,300 km of one of the Earth's most active meandering rivers: the Ucayali River in Peru. Meandering is a form of slope adjustment with more sinuous channel paths leading to. More recently, worldwide satellite imagery collected at least every 18 days by the NASA Landsat family of satellites offers the potential to reveal the secret lives of migrating, meandering rivers. Meanders are broad, looping (sinuous) bends in a stream channel. Migration occurring between snapshots has thus largely remained a mystery. Understanding how rivers move across their floodplains requires snapshots of planforms over long time periods from aerial photography or historic maps and surveys which are often taken at irregular and long intervals. At the reach scale, concepts from nonlinear dynamic theory are applied to river centerlines to determine if the dynamic nonlinearities driving meander evolution are preserved in the reachwide planform structure. A simple yet physically-based model of long-time meander migration is employed to understand the dynamic trajectories of individual meander bends and establish relationships between historic dynamics and cutoff bend geometry. This work investigates the relationships between the alluring planform geometries of meandering rivers, the dynamics of individual meander bend migration, and the dynamic processes driving meander evolution. Meandering rivers are dynamic agents of geomorphic change that rework landscapes through migration while maintaining beautiful looping planforms.