Causes of soil erosion

Question 1

What are the two types of soil erosion

Answer 1

• Wind erosion
• Water erosion

Question 2

What is wind erosion

Answer 2

A natural process that moves soil from one location to another by wind power

Question 3

What is water erosion

Answer 3

The removal of soil by water

Question 4

What are the three types of water erosion

Answer 4

• Rain splash erosion
• Surface runoff erosion
• Slumping and landslide erosion

Question 5

What is rain splash erosion

Answer 5

Raindrop lands and hits the soil dislodging the particles dispersing it in all directions

Question 6

What is surface runoff erosion

Answer 6

Water is no longer able to infiltrate into the soil causing soil particles to be transported by surface runoff

Question 7

What is slumping and landslide erosion

Answer 7

When soil on slopes becomes very wet & increased mass and lubrication of the water causes the downwards movement of large amounts of soil.

Question 8

What are the conditions when slumping and landslide erosion is more likely

Answer 8

After deforestation when tree roots decompose the soil becomes unstable and after heavy rain landslides are more likely to occur

Question 9

How does vegetation reduce the rates of soil erosion (5 ways)

Answer 9

• Acts as a natural windbreak (reduces wind velocity & kinetic energy that removes soil particles)
• Acts as protection from raindrops
• Soil organic matter binds soil particles together
• Plant roots hold soil together
• Increase rates of infiltration which reduces rate of surface run off

Question 10

What are 6 human activities that increase the rate of soil erosion

Answer 10

• Vegetation removal
• Ploughing vulnerable soils
• Overgrazing
• Reduced soil biota
• Soil compaction
• Cultivating steep slopes

Question 11

How does vegetation removal increase the rate of soil erosion

Answer 11

Removing vegetation removes the protection from erosion increasing the impact of raindrops on soil surfaces and increasing the effects of wind velocity on soil

Question 12

How does ploughing vulnerable soils increase the rate of soil erosion

Answer 12

Ploughing breaks up soil structure, exposing soil particles to erosion by water or wind

Question 13

How does overgrazing increase the rate of soil erosion

Answer 13

A high density of livestock grazing will eat the vegetation faster than it can grow increasing exposure of soil and the risk of erosion. Disturbance from hooves and root damage also increases the risk of soil erosion

Question 14

How does reduced soil biota increase the rate of soil erosion

Question 15

How does soil compaction increase the rate of soil erosion

Answer 15

Compacted soil has smaller interstitial spaces which reduces the infiltration rate so rainfall will produce surface run off increasing erosion

Question 16

What is the cause of soil compaction

Answer 16

Use of heavy machinery, lots of livestock and a reduction in detritivores causes soil compaction

Question 17

How does cultivating steep slopes increase the rate of soil erosion

Answer 17

Cultivating steep slopes causes surface run off water to run more rapidly down the slopes which means it has more kinetic energy to pick up soil particles

Question 18

What are 4 effects of accelerated soil erosion

Answer 18

• Reduced productivity
• Sediments in rivers and reservoirs
• Increased atmospheric particles
• Desertification

Question 19

How does reduced productivity accelerate soil erosion

Answer 19

Top soil that is eroded is usually more fertile leaving behind less fertile soil so plant growth may be reduced leading to smaller harvests

Question 20

How does sediments in rivers and reservoirs accelerate soil erosion

Question 21

How does increased atmospheric particles accelerate soil erosion

Answer 21

Wind erosion increases level of atmospheric particulates

Question 22

How does desertification accelerate soil erosion

Answer 22

Soil erosion is one of the processes that causes