Processes Flashcards
Where do fluvial processes take place?
In coastal environments such as river mouths or low-energy estuarine environments.
What erosion do fluvial processes cause?
In the upper catchment most of the rivers sediment load is eroded, from weathering/MM processes, the material in the channel comes from valley sides.
Why do rivers deposit their sediment load when entering the sea? (3 reasons)
Velocity/energy reduced when flowing channel enters almost static body of sea water and resistance as currents may be moving in different directions. Also flocculation (fine clay particles clump due to electrical charges/saline conditions. are heavier so sink).
Why do Aeolian processes take place?
Because coasts are exposed to open surfaces and winds.
What is deflation?
clay/silt-sized particles picked up by wind in dry lands
What erosion do Aeolian processes cause?
Sand particles moved by surface rolling or creep and saltation (sand heavy compared to silt/clay so little suspension). Dry sand is easy to pick up.
What happens when erosive force increases?
Wind velocity also increases, V of 2-4m/s causes 8 fold rise in erosion.
How does wind transport material?
same as rivers/waves (apart from solution), those too heavy for saltation are moved by surface creep.
When is material in wind deposited?
When wind speed falls, usually due to inland surface friction from irregularities greater than the sea.
