soil erosion and conservation

Question 1

define soil erosion

Answer 1

geological process in which earthen material is worn away and transported by natural processes such as wind and water

Question 2

what is transported material called

Answer 2

sediment

Question 3

define weathering

Answer 3

involves the breakdown of rock but does not involve movement of particles

Question 4

list 5 natural processes causing erosion

Answer 4

physical erosion - landslides
erosion by water - rain rivers floods
erosion by wind
erosion by ice - downhill movement of glaciers
thermal erosion - erosion of permafrost along a river or coastline due to changes in temp

Question 5

what are 3 human activities causing erosion

Answer 5

altering of vegetation - deforestation ploughing for agri
global warming
farming practices - overgrazing of animals and mono cropping

Question 6

define deforestation

Answer 6

refers to purposeful clearing of forested land

Question 7

purpose of deforestation

Answer 7

done to make space for planting crops animal grazing to obtain wood manufacturing and construction

Question 8

what are the two main methods of deforestation

Answer 8

clear cutting and slash and burn

Question 9

define clear cutting

Answer 9

clears down all the trees in one area with the aid of machinery
most financially efficient way of clearing trees

Question 10

define slash and burn

Answer 10

ash fertilises land for agriculture but land is only fertile for a few years

Question 11

define ploughing

Answer 11

process of loosening and turning over the soil to uproot weeds and aerate soil

Question 12

what is the leading cause of deforestation

Answer 12

agriculture for at least 80% in tropics

Question 13

list 4 effects of deforestation

Answer 13

fewer trees to carry out photosynthesis resulting in more carbon dioxide being released into atmosphere which contributes to global warming
threatens worlds biodiversity
makes more prone to soil erosion and makes remaining trees more vulnerable to fires due to change from a closed moist environment to an open dry one

Question 14

what does increased erosion lead to

Answer 14

soil infertility flooding landslides

Question 15

list 4 effects of ploughing

Answer 15

reduced soil moisture and therefore less suitable in dry conditions
soil loss
disturbs soil organisms useful in fertilising soil
releases carbon dioxide from organic matter into atmosphere

Question 16

how does global warming cause soil erosion

Answer 16

results in climate change which increases the frequency and intensity of storms which can cause soil erosion
melting of glaciers causes more rill gully and valley erosion
also results in rise of sea level which causes beach erosion as waves reach further up shore

Question 17

define sheet erosion

Answer 17

a shallow sheet of water flowing over ground surface resulting in removal of uniform layer of soil from the surface

Question 18

define rill erosion

Answer 18

sheet erosion resulting in water flowing in deeper and faster flowing channels

Question 19

define gully erosion

Answer 19

rill erosion develops into gully erosion with deeper and wider channels forming streams

Question 20

define valley erosion

Answer 20

rushing streams and rivers wear away their banks creating larger and larger valleys

Question 21

list four farming practices causing erosion

Answer 21

ploughing
monocropping monoculture - depleted soil fertility and degradation
overgrazing of animals - destroys top soil cover making soil prone to erosion
heavy machinery - compaction of soil reduces air spaces in soil reducing amount of water can infiltrate soil increasing surface run off

Question 22

list 4 effects of soil erosion

Answer 22

reduced soil fertility
soil degradation
increased water pollution and sedimentation
increased flooding

Question 23

list 5 ways to prevent soil erosion

Answer 23

crop rotation
avoid overgrazing with pasture rotation
reafforestation
hedgerows
terracing