Self-Stabilizing Tendencies of Alluvial Channels

Abstract

Channels constructed in coarse alluvial material tend to develop an armor coat at the bed's surface protecting the material beneath the top layer from further erosion. A method is outlined which permit the prediction of the eroded material. Based on these results, it is possible to make an estimate on the minimum amount of material to be eroded prior to development of a stable condition resulting from amoring. An attempt is made to determine those condition which result in a finally stable bed. This leads to a design criterion for stable channels constructed in coarse nonuniform alluvial material. This design criterion integrates the stabilizing influence of all grain sizes present in a self-stabilized armor coat and permits operating the channel at a preset factor of safety.