7.2.1. Knick point

A knick point is a sudden break or irregularity in the gradient along the long profile of a river. Some knick points are sharply defined, for example waterfalls, whereas others are barely noticeable. Although a number of factors can cause such features to occur, they are most commonly attributed to rejuvenation.

When a river is rejuvenated, adjustment to the new base level starts at the sea and gradually works its way up the river's course. The river gains renewed cutting power (in the form of vertical erosion), which encourages it to adjust its long profile. In this sense the knick point is where the old long profile joins the new.