Abstract Neck and chute cutoffs along meandering rivers are near-instantaneous morphodynamic perturbations that drive modification of planform channel geometry and kinematics at the cutoff site and in adjacent bends. Despite their ubiquity, quantitative and predictive linkages between post-cutoff planform bend geometry and subsequent bend kinematics remain limited. Here, using a 37-year record of Landsat-derived river channel centrelines from a meandering reach of the Trinity River in Texas (USA) and a newly developed directed graph-based approach for high-resolution channel tracking, we identify a linkage between post-cutoff bend curvature and the magnitude, spatial extent, and temporal duration of cutoff influence on local and non-local channel bend kinematics. We further explore this relationship using a kinematic model of meandering applied to synthetically generated river reaches and the Landsat-derived Trinity River centrelines. While the model captures the observed linkages between post-cutoff bend curvature and resultant bend kinematics, it underpredicts the magnitude of cutoff influence observed in the real centreline data – particularly at the cutoff site – by up to one order of magnitude. Our results provide a promising advance in the characterization and prediction of the spatiotemporal impact of cutoffs on local and non-local post-cutoff channel bend kinematics.

Abstract There has been debate over the processes acting on deep-water channels, with comparisons made to the evolution of meandering fluvial systems. We characterized a three-dimensional seismic-reflection dataset of the Joshua deep-water channel–levee system located in the eastern Gulf of Mexico and interpreted 13 horizons showing its kinematic evolution over a 25 km reach. Over this reach, we documented channel migration through systematic bend expansion and downstream translation, which was sustained through channel aggradation as sinuosity increased from 1.25 to 2.3 at abandonment. An abrupt decrease in sinuosity was associated with a neck cutoff, which changed the subsequent migration direction of the channel in that locality. These processes are analogous to the evolution of meandering fluvial systems. We show that increasing channel sinuosity correlates to a reduction in channel slope and hypothesize that this promoted increasingly depositional turbidity currents that led to channel aggradation. Using a simple forward stratigraphic model in which vertical movements of the channel are governed by a stream power law, we show how aggradation can be driven autogenically. Trends in sinuosity, aggradation and slope are in broad agreement between the Joshua Channel and the model. This highlights the potential importance of intrinsic channel processes as a control on system evolution.