Fluvial Patterns and Processes

Question 1

Name the processes of fluvial erosion

Answer 1

~Hydraulic action: force of water hitting off landscape

~Abrasion: Rock smashes against landscape

~Attrition: Small pieces of rock hitting off of each other

~Solution: soft rock is dissolved by acid rain

Question 2

What are the types of transportation in a river?

Answer 2

Traction: River rolls large pieces of sediment on the river bed

Saltation: Sediment becomes smaller (Attrition) and is bounced off the river bed

Suspension: Sediment becomes smaller (attrition) and is carried down the river

Solution: Dissolved sediment (carbonation) floats in river

Question 3

Name 2 features of a river in the youthful stage

Answer 3

-Waterfall
-V-shaped Valley

Question 4

Name a feature of fluvial erosion

Answer 4

Waterfalls

Question 5

Name a feature of fluvial deposition

Answer 5

Levee

Question 6

How is a waterfall formed? Give an example of a waterfall

Answer 6

-Water erodes soft rock through process of hydraulic action, but not hard rock (differential erosion)
-Eventually erodes down to a plunge pool
-Small particles erode back of soft rock, causing further erosion (abrasion)
-Overhang rock eventually breaks and collapses

e.g. Powerscourt waterfall, Co. Wexford

Question 7

How is a levee formed?

Answer 7

-When a river floods, it spreads out over the floodplain
-It loses energy and deposits its load close to the banks of the river
-After many floods, the deposits build up and form raised banks of sediment on the sides, forming a levee

Question 8

Name a feature of a river in the mature stage

Answer 8

-Meanders
-Wide valleys

Question 9

Name a feature of a river in the old stage

Answer 9

-Ox-bow lakes
-Levees

Question 10

What is a river source?

Answer 10

Where the river begins

Question 11

What is the river mouth?

Answer 11

Where the river enters the sea