Stream Restoration Terminology
The representative cross-sectional shape and area of a stream channel.
Ephemeral Stream: A stream that only flows during and immediately after a rain event and is not connected to the water table.
The area adjacent to a stream that is subject to periodic flooding when the stream overtops its banks.
The study of the landform evolution related to stream systems, including related disciplines of geology, hydrology and hydraulics, sediment transport, soil mechanics and effects of vegetation. These processes, interactions and pressures operating on river systems change independent variables such as discharge, sediment load and valley slope, which then create adjustments in the dependent variables of sediment load and particle size, hydraulic characteristics and channel and valley morphology.
An erosional feature where an abrupt vertical drop in the stream bed occurs. This sudden change in elevation can indicate that the bed is unstable.
The process of lowering a streambed through headcuts or other mechanisms. An incised stream is disconnected from the adjacent floodplain.
A measurement of the stream's plan features, including radius of curvature, meander wavelength, meander belt width, stream length and valley length. Patterns can be generally described as straight, braided, meandering or anastomosed.
A longitudinal profile is created by measuring and plotting elevations of the channel bed, water surface, bankfull and low bank height. Profile points are surveyed at prescribed intervals and at significant breaks in slope such as the head of a riffle or the head of a pool and can be used to assess changes in river slope compared to valley slope, which affect sediment transport, stream competence and the balance of energy.
An area of a stream characterized by slow current and a depth greater than riffle areas.
An area of a stream characterized by fast current and shallow depth.
A transitional area of a stream between a riffle and a pool characterized by a rapid, non-turbulent flow.
A watershed is the geographic area through which water flows across the land and drains into a common body of water such as a stream, river, lake or ocean. Usually synonymous with "Drainage Area" and "Basin."