profileknickpoints

Profile knickpoints are localized steep reaches within a stream's longitudinal profile, representing a significant change in channel gradient. These features are often indicative of geological or hydrological disturbances. Geological knickpoints can arise from base-level fall, such as a drop in sea level or uplift of the landmass, causing a river to incise more rapidly upstream of the change. Tectonic activity, like faulting, can also create abrupt changes in stream gradient, forming knickpoints. Lithological variations can also contribute, where a stream flows over a resistant rock layer followed by a less resistant one, leading to differential erosion and a knickpoint.

Hydrologically, knickpoints can be caused by factors such as changes in water discharge, sediment supply, or the presence of resistant debris dams. Over time, a knickpoint will migrate upstream as erosion continues. Studying the location, shape, and migration rate of profile knickpoints can provide valuable insights into the geomorphic history and tectonic setting of a river system. They are a key indicator of active landscape evolution and dynamic river systems.