Misfit Stream - Origin of Misfit Streams

Origin of Misfit Streams

An under fit stream can result when glaciation modifies the landscape by creating glacial troughs the rivers that occupy such valleys after the ice has retreated are not in proportion with the size of the valley. Given the scale of most glacial troughs almost all of them contain misfit streams. Misfit streams can also be caused by reductions in the discharge of the stream. Channel size responds rapidly to variations in discharge, but valley size responds over much longer timescales. Many causes of reduced discharges are possible. If misfit streams are widespread in an area, climate change, particularly a reduction in precipitation, is likely to be the cause. If a single river appears to be a misfit stream, it may be as a result of anthropogenic interference through groundwater extraction or dam construction upstream. Natural causes include stream capture or other changes in drainage patterns. For instance, New Zealand's largest river (the Waikato) used to flow through the Hauraki Plains to the North Island's east coast, but changed its course to exit on the west coast due to a large volcanic eruption, leaving its former course through the 1-km wide Hinuera Gap occupied by only a small stream.