Stream Channels & Valleys
Channel cut directly into solid bedrock
Bedrock channel
Lowest elevation a stream can erode to
Base level
General term for sediment deposited by streams
Alluvium
Flood caused by heavy rain or rapid snowmelt over a region
Regional flood
Upper surface of the zone of saturation
Water table
Channel composed of loose, unconsolidated sediment
Alluvial channel
Lowest possible base level for a stream
Ultimate base level
Fan-shaped deposit formed where a stream exits a narrow valley
Alluvial fan
Flood that occurs with little warning
Flash flood
Ability of rock or sediment to transmit water
Permeability
Sweeping bends formed in an alluvial channel
Meandering channel
Broad, flat valley floor formed by river meandering
Floodplain
Raised riverbank formed by repeated flooding
Natural levee
Man-made structures built to increase river capacity
Artificial levees
Permeable rock layer that stores and transmits groundwater
Aquifer
Erosional feature on the outside of a meander
Cut bank
Meander deeply cut into bedrock
Incised meander
Poorly drained area behind a natural levee
Back swamp
Dam designed to store water and release it slowly
Flood-control dam
Cone-shaped lowering of the water table around a well
Cone of depression
Disconnected meander formed after a cutoff
Oxbow lake
Step-like surfaces formed after a drop in base level
Stream terraces
Small streams branching off within a delta
Distributaries
Shortening a river to increase velocity
Artificial cutoff
Landscape formed by dissolution of limestone by groundwater
Karst topography