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Predicting the planform configuration of the braided Toklat River, AK with a suite of rule-based models

July 30, 2013

An ensemble of rule-based models was constructed to assess possible future braided river planform configurations for the Toklat River in Denali National Park and Preserve, Alaska. This approach combined an analysis of large-scale influences on stability with several reduced-complexity models to produce the predictions at a practical level for managers concerned about the persistence of bank erosion while acknowledging the great uncertainty in any landscape prediction. First, a model of confluence angles reproduced observed angles of a major confluence, but showed limited susceptibility to a major rearrangement of the channel planform downstream. Second, a probabilistic map of channel locations was created with a two-parameter channel avulsion model. The predicted channel belt location was concentrated in the same area as the current channel belt. Finally, a suite of valley-scale channel and braid plain characteristics were extracted from a light detection and ranging (LiDAR)-derived surface. The characteristics demonstrated large-scale stabilizing topographic influences on channel planform. The combination of independent analyses increased confidence in the conclusion that the Toklat River braided planform is a dynamically stable system due to large and persistent valley-scale influences, and that a range of avulsive perturbations are likely to result in a relatively unchanged planform configuration in the short term.

Citation Information

Publication Year 2013
Title Predicting the planform configuration of the braided Toklat River, AK with a suite of rule-based models
DOI 10.1111/jawr.12029
Authors Charles J. Podolak
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of the American Water Resources Association
Index ID 70041493
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Water