Experimental study on the erosion law of diluted debris flow

Diluted debris flow has a strong capacity of sediment delivery, which may erode debris flow channel significantly during the movement from upstream to downstream. In this paper, the theoretical analysis combined with field flume experiments, a preliminary study on the erosion law of diluted debris flow has been conducted. The process of armoring should be considered in the initial erosion of non-uniform channel bed material. Therefore, the erosion process of non-uniform channel bed material scoured by diluted debris flow can be classified as three modes according to critical criterion of armoring layer. In addition, the calculation methods of bed scour depth of three erosion modes mentioned above were presented. The value of erosion coefficient was also explored according to filed flume experiments. The key issue of repeated erosion of diluted debris flow is whether the bed surface structure formed during the last process of scouring can be damaged or regenerated. At last, the calculation method of scour depth after repeated erosion was analyzed according to the experimental results from the field flume experiments.