CHANNEL, a Model of Channel Erosion by Shear, Scour and Channel Headwall Propagation: Part 1. Model Development

摘要

Channel erosion in upland watersheds is the general topic of the report, with specific emphasis on the fundamental mechanics of channel erosion resulting from the development of channel (gully) headwalls and scour holes, and from general shear excess. The emphasis is on erosion in channels with cohesive boundaries. Entry of sediment into our nations waterways is a serious pollution problem, intensified by the chemicals adsorbed on the exchange phase of clay particles in the sediment. The subject of upland erosion from rill and interrill areas has been the subject of intensive investigations, both empirical and physically based. Channel erosion has been studied primarily from an empirical basis, with virtually little physically based information on channel headwall development and propagation and of channel bank failure. Both of these mechanisms are major sources of sediment. In the research conducted under the project, models were developed which predict channel erosion resulting from shear in gradually varied flow, shearing forces resulting from submerged jets and hydraulic jumps and shearing forces resulting from free jets impinging a plunge pool.