Week 13: River landforms

Question 1

Define erosion.

Answer 1

The process of wearing away rocks and soil by natural forces like water and wind.

Question 2

What is hydraulic action?

Answer 2

The force of water hitting the riverbank, causing erosion.

Question 3

True or false: Abrasion involves rocks scraping against the riverbed.

Answer 3

TRUE

Abrasion occurs when sediment carried by water grinds against the riverbed.

Question 4

Fill in the blank: Attrition is when rocks _______ against each other.

Answer 4

collide

Question 5

What is a meander?

Answer 5

A bend in a river formed by erosion and deposition processes.

Question 6

Define oxbow lake.

Answer 6

A crescent-shaped lake formed when a meander is cut off from the river.

Question 7

What is deposition?

Answer 7

The process of sediment being laid down in a new location by water.

Question 8

True or false: Floodplains are areas of land that are prone to flooding.

Answer 8

TRUE

Floodplains are fertile areas that can support agriculture.

Question 9

Fill in the blank: Delta forms at the _______ of a river.

Answer 9

mouth

Question 10

What is a levee?

Answer 10

A natural or artificial embankment along a river to prevent flooding.

Question 11

True or false: V-shaped valleys are formed by glacial activity.

Answer 11

FALSE

V-shaped valleys are typically formed by river erosion.

Question 12

Fill in the blank: Alluvium is sediment deposited by _______.

Answer 12

running water

Question 13

What is a confluence?

Answer 13

The point where two rivers meet and combine their waters.

Question 14

What is silt?

Answer 14

Fine sediment that is often deposited in riverbeds and floodplains.

Question 15

True or false: Estuaries are where freshwater meets saltwater.

Answer 15

TRUE

Estuaries are rich in biodiversity and crucial for many species.

Question 16

What is a cut bank?

Answer 16

The outer bank of a meander where erosion occurs.

Question 17

Fill in the blank: Sediment is transported by _______.

Answer 17

water

Question 18

Define fluvial processes.

Answer 18

The processes related to the movement of water and sediment in rivers.

Question 19

What is bank erosion?

Answer 19

The wearing away of the riverbank due to water flow.

Question 20

True or false: Lateral erosion widens a river valley.

Answer 20

TRUE

Lateral erosion occurs as the river erodes its banks.

Question 21

Fill in the blank: Interlocking spurs are formed by a river’s _______.

Answer 21

meandering

Question 22

What is a natural levee?

Answer 22

An elevated area along a river formed by sediment deposition during floods.

Question 23

Explain what is happening in the image.

Answer 23

1) Soft rock eroded by hydraulic action
2) Hard rock unsupported gravity causes it to fall.
3) Traction and abrasion causes plunge pool to get bigger
4) Waterfall retreats back.
5) Gorge is formed

Question 24

Explain what is happening in the image.

Answer 24

1) Vertical erosion from abrasion
2) Sides of valley eroded by the weather
3) sides collapse from gravity.

Question 25

Explain what is happening in the image.

Answer 25

1) Helicoidal flow pushes high energy water to the outside bend 2) Deep water and faster velocity 3) Hydraulic action causes lateral erosion (River cliff) 4) Inside bend causes deposition 5) shallow water no friction or energy (Slip off slope)