| Many bedrock channels are composed partly of alluvium and partly of bare rock、 and abrasion from the influence of bed load is known to be a ubiquitous and principal mechanism of fluvial bedrock incision. The results of recent investigations have suggested that the bedrock incision rate depends on rock strength、 sediment supply、 grain size and the areal fraction of bedrock exposure. In this study、 the authors performed laboratory experiments to evaluate the influence of rock properties on the bedrock incision rate. The results showed that rock strength and the effective porosity of bedrock have a significant effect on this rate. As the effective porosity of weathered bedrock is greater than that of fresh bedrock、 these results suggest that wetting/drying cycles and freeze/thaw cycles can affect the incision rate and the resulting bedrock channel morphology. |
