Unit 1- Rivers

Question 1

What and where is a river provided?

Answer 1

The source (upland)

Question 2

Small river that later joins a larger river

Answer 2

Tributary

Question 3

Rivers meet?

Answer 3

confluence

Question 4

What is a drainage basin?

Answer 4

• Land around river
• Water (rain) flows/ is drained by that river

Question 5

What is a watershed?

Answer 5

-Highest point of land surrounding river
- all water (gravity and rain) flows towards this river

Question 6

4 types of fluival erosion

Answer 6

Hydraulic action
Abraision
Attrition
Solution

Question 7

What is hydraulic action?

Answer 7

Rapid high energy water hits rock and is pushed inside gaps of rock
therefore erodes itt

Question 8

What is abraision?

Answer 8

-Rocks carried by the water grinds down on other rocks
-Cuases erosion

Question 9

What is attrition?

Answer 9

-Rocks carried by water collide wth other rocks
-Cuase erosion

Question 10

What is solution?

Answer 10

Rocks (limestone) dissolve

Question 11

x4

Transportation?

Answer 11

-Traction
-Saltation
-Solution
-Suspension

Question 12

What is traction?

Answer 12

Large rocks roll across floor

Question 13

What is saltation?

Answer 13

-Rocks bounce against other rocks

Question 14

What is solution?

Answer 14

-dissolved materials flow with water

Question 15

What is suspension?

Answer 15

• Small rocks held high in water and flow with water

Question 16

What and when does depostion happen?

Answer 16

• Sediment discarded by water
• Water low energy / slow

Question 17

How is a v-shaped valley formed?

Answer 17

• Weathering cuases top corners to erode
• Sediment falls into river
• cuases a v shape to form

Question 18

How is a waterfall formed?

Answer 18

• Layer of hard rock above soft rock
• Soft rock eroded backwards —> plunge pool
• Hard rock above collapses

forms a backwards pathway

Question 19

How is a gorge formed?

Answer 19

• Waterfall continuously created
• Backwards pathway

(land retreats/ slowly erroded backwards)

Question 20

How is an Ox-Bow lake formed?

Answer 20

• Thalweg of water moves around hard rock/ erodes a slight bend
• Cuases slow water to move near hard rock and deposit material —-> slip of slope
• Larger bend made due to hyadralic action and abraision —–> meander
• Hard rock in corners eventually erode—–> straight river
• Water travels stright cutting off curve
• Curve cut of becomes and ox-bow lake

Question 21

How is an inter-locking spur formed?

Answer 21

-Thalweg of water erodes sofdter rock
-Cuases curves/bends

Question 22

Why are slip off slopes formed in meanders?

Answer 22

-Water is slower on inside bend
-Less energy
-Water deposites material
-Cuases more friction which furthers deposition