Fluvial Landforms; Erosional And Depositional

Front 1

Canyon

Back 1

-Erosional Landform
-Steep-walled, bedrock-bound valley.
-Characteristic of stream that is young, rejuvenated (crustal uplift due to tectonic activity), or located in semi-arid/arid area.

Front 2

Plunge pool

Back 2

-Erosional Landform
-Depression excavated by waterfall.
-Force of water erodes rock backwards at water’s surface and at the channel bed
-Eventually you’ll get a mass wasting of the top of the waterfall

Front 3

Delta

Back 3

-Depositional Landform
-Deposit of alluvium in body of standing water.
-As the small stream enters a lake the capacity decreases a lot.

Front 4

Alluvial Fan

Back 4

-Depositional Landform
-Deposit of alluvium onto main valley floor.
-Stream flowing and empties into a wide valley and the water spreads and the capacity reduces,
-Alpine Areas

Front 5

Levee

Back 5

-Depositional Landform
-Elongated deposit parallel to stream channel.
-Occur with flooding; decrease of capacity (depositions on the edges when the water spills out)

Front 6

Braided Channel

Back 6

-Depositional Landform
-Alluvium deposited as elongated bars parallel to stream flow.
-Braided stream: happens when sediment is deposited on the floor, and the stream is on other sides
-Steps to a Braided Stream
1. Coarse sediment deposited first
2. Finer sediment gets caught in opening s of the coarse sediment second
3. As it gets bigger it deflects water to the side eroding the sides of the stream widening the stream which will lower the water level of the stream, exposing the bars
4. Stable bars give way to vegetation which make them permanent as the roots keep the bar in place
-Initial Factors Include: Stream channel becoming shallow and wide, Reduced discharge, Addition of new sediment, Presence of non-cohesive material (Sand, gravel)