The Influence of Thermal Erosion at River Bed Deformation in Permafrost Areas

The study is focused on the deformations caused by the impact of water flow in a river channel composed of meltable permafrost bed materials. It is based on the results of laboratory and mathematical simulation. The results of numerical calculations are compared with data of laboratory and field observations. The study shows that a comprehensive and adequate model of river channel deformations should take into account not only ablation, but also other factors, including heat transfer in the soil, sediment transport, and bank slope collapses. Experiments in a hydraulic flume were good enough to reproduce the effect of delayed collapse, consisting in nonsimultaneous impacts of channel-forming rock melting and a freshet. The major factors that have an effect on channel transformations in permafrost-zone rivers are identified. © 2021 American Society of Civil Engineers.