Erosion of Hard Rock Bed

Definition

As the river passes over the hard rock bed, it scours rock. The continuous scouring of the rock produces a vertical drop in the river channel. It behaves like the waterfall. The energy of the falling water will continue to erode the bed of the river so that eventually a plunge pool will develop at the base of the waterfall. The plunge pool develops initially because the force of the falling water creates a slightly deeper pool in the bed of the river. As the rivers’ bed load falls into the pool it swirls and scours the base of the pool causing it to deepen.