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)