River Processes

Warning: this page under construction....

The shape of a watershed (the basin within which water falls and exits through a river channel) determines both the behavior and the shape of the stream, and is shaped by it.

 

Upland areas are dominated by erosion, and small, steep, cobbly streams. Sediment supply in the ?? region is greater than the river channel's power to move it. Sediment is stored and transported in the middle of the watershed. Sediment is always moving through the system, but large annual flows and rare floods move the most material at once. 

 

Farther downstream, where the basin is flatter and sediment has accumulated in the valley bottoms, flood plains develop, and the stream channel may migrate back and forth across the floodplain over time. As the channel moves away from one side, a point bar accumulates sediment and debris, while on the opposite bank, a steep cut bank forms as material is eroded away by the moving river. 

 

The flattest downstream areas are dominated by deposition of sediment and slower-moving water in broad, mainstem channels. Here, multiple channels and deltas may form as sediment is deposited into a larger channel, lake, or the sea.

 

Source - Transport - Accumulation Zones

sediment supply trends downstream

longitudinal profile downstream

slope downstream

discharge (flow magnitude) downstream

sediment grain size downstream

volume of stored alluvium downstream

stream power downstream (?)

 

morpholgical types:

steep mountainn streams, confined valleys 

-->

partly confined valleys, floodplain pockets 

-->

laterally unconfined (alluvial) valleys, continuous floodplains along banks 

-->

delta (?)

Very specific things that should be included and described in detail:

floodplains

meanders

tributaries

elevation change

what is a watershed