soil erosion

Question 1

list the types of soil erosion

Answer 1

1) wind erosion
2) rain splash erosion
3) surface run off erosion
4) slumping and landslides

Question 2

what is wind erosion

Answer 2

when some soils become dry they are less likely to be loose with little cohesion between particles.

when it is windy the soil is unprotected and is blow away

Question 3

outline rain splash erosion

Answer 3

when soil particles are dislodged by the splash of a raindrop and soil particles are dispersed in all directions

Question 4

outline surface run off erosion

Answer 4

caused by surface run off when infiltration capacity of soil has been exceeded. water flows over the surface of the soil dislodging soil particles

Question 5

outline slumping and landslide erosion

Answer 5

when soil on sloped becomes wet and the increased mass and lubrication of the water makes the downward movement of large amounts of soil more likely

Question 6

how can vegetation reduce the rate of soil erosion

Answer 6

• acts as a natural wind break reducing wind velocity and therefore the kinetic energy to carry soil
• vegetation cover and leaf litter reduce impact of raindrops
• soil organic matter helps to bind soil particles together
• plant roots hold soil together
• helps increase infiltration of water decreasing surface run off

Question 7

list the human activities which increase the rate of soil erosion

Answer 7

1) vegetation removal
2) ploughing venerable soils
3) overgrazing
4) reducing soil biota
5) soil compaction
6) cultivating steep slopes

Question 8

outline how vegetation removal increases soil erosion

Answer 8

removes protection from erosion such as roots binding soil together or acting as a natural wind break

Question 9

outline how ploughing vulnerable soils increases erosion

Answer 9

it breaks up the soil structure exposing soil particles to erosion by water or wind

Question 10

outline how over grazing increases soil erosion

Answer 10

if livestock density is too high then vegetation will be eaten faster than it can grow increasing exposure of the soil and risk of erosion

Question 11

outline how reduced soil biota increases erosion

Answer 11

ploughing reduces soil biota as well as the use of pesticides

• decreased decomposition of dead organic matter so plants cant grow due to lack of nutrients decreasing vegetation cover
• decomposition which produces humus which increases adhesion between soil decreases
• works aerate the soil increasing drainage rates therefore soils may become water logged increasing surface run off

Question 12

outline how soil compaction can increase erosion

Answer 12

creates smaller interistual spaces which reduces infiltration rates so it is more likely rain fall will produce surface run off erosion

Question 13

outline how cultivating steep slopes increases soil erosion

Answer 13

surface run off flows more rapidly down steeper slopes so has more kinetic energy to pick up and carry soil. Cultivating these slopes disturbs the soil allowing it to erode more when this occurs