Wednesday 19th November 2014
Different River Terms
Knickpoint:
A knickpoint is a term in geomorphology to describe a location of a river or channel where there is a sharp change in channel slope, such as a waterfall or lake. Knickpoints reflect different conditions and processes on the river often caused by previous erosion due to glaciation or variance in lithology.
Knickpoints are formed by the influence of tectonics, climate history, and/or lithology. For example, uplift along a fault over which a river is flowing will often result in an unusually steep reach along a channel, known as a knickzone. Glaciation resulting in a hanging valley are often prime spots for knickpoints. If lithology of the rock varies, such as shale amongst igneous rock, erosion will occur more steadily in the softer rock than the surrounding.
River Terraces:
Rejuvenating river can erode vertically into the former flood plain to produce features called river terraces. If vertical erosion is rapid then paired terraces are formed either side of the channel. If vertical erosion is slower though, unpaired terraces form as the river is given opportunity to meander. River terraces are particularly useful for settlements as they provide flat areas above the present floodplain. Oxford, Cambridge and London all developed on the river terraces of the Isis, Cam and Thame
Incised Meander:
Incised meanders are meanders which are particularly well developed and occur when a river’s base level has
