lab 8 stream processes. channel types braided - steeper, large sediment supply meandering - less...
TRANSCRIPT
Channel Types
• Braided - steeper, large sediment supply
• Meandering - less steep, lower sediment supply
Terminology
• Flood – river overflows its banks• Alluvium – stream deposits• Drainage system – network of streams
and rivers that drain a given area of land• Many types of drainage patterns (e.g., dendritic,
rectangular, trellis, etc.)
Drainage Basins and Divides
• Drainage basin – area of land drained by one stream
• Divides – linear boundaries that separate one drainage basin from another.– Continental divide:
Rocky Mts.
Stream Processes
• Weathering– Dominant process upstream– Headward erosion – streams erode into V-
shapes uphill.– Erode their own valleys and channels
• Transport• Deposition
– Dominant process downstream– Velocity decreases and sediment dumped
River Valley Forms and Processes
• Gradient – steepness of slope • Gradient = (height)/(distance)
• Base level – lowest level to which stream can theoretically erode– Imaginary line between erosion and
deposition• Discharge – rate of stream flow at a given
time and location• Load – the amount of material that is
transported by a stream (mostly sediment)