What is the process known as abrasion in relation to river flow?

Abrasion is a crucial process in the geomorphology of rivers, referring specifically to the wearing away of the riverbed as the river flows. This occurs when the sediment and rocks that the river carries act as tools that grind and erode the river's bed and banks. The force of the water moving these particles causes friction against the riverbed, gradually wearing it down. This process contributes to the shaping of the river's channel and surrounding landscape, facilitating the ongoing cycle of erosion and sediment transport.

In the context of river flow, this means that as rivers transport a load of sediments, they simultaneously alter their physical environment. Abrasion is significant because it not only affects the depth and shape of the river channel, but it also influences the overall dynamics of riverine ecosystems. Understanding this process is essential for grasping the broader concepts of river erosion, sedimentation, and landscape formation.