Desposition And Erosion In An Alluvial Channel

Deposition and erosion of sediment particles are studied experimentally in a laboratory channel. It was found that for the same hydraulic conditions, deposition gives different numerical results than erosion. While erosion has been sufficiently studied before, a systematic investigation on deposition has - to our knowledge - never been done before. Our results are summarized on Fig. 9: two families of curves- for deposition and for erosion - a r e shown. For the same sedimentary material and the same shear stress, τ∗, the number of particles in movement, N", is smaller for erosion than for deposition. If one compares our results with Shields' function, one notices that the particle motion is more intense if the Reynolds number, Re ∗, are smaller. To obtain our data a special “particle-counting” system was developed, which is depicted in Fig. 2.