People And Climate

Question 1

Human activities and numbers are influenced by the climate

Answer 1

. Climate effects agricultural productivity and water availability ( this means that population size and lifestyles in different climate zones are different)

Question 2

Polar climates (3)

Answer 2

. Above 66 degrees latitude in the northern and Southern Hemisphere
. Little precipitation
. Two polar regions- Arctic and Antarctica

Question 3

Arctic

Answer 3

. Covers Arctic Ocean ( mostly ice )
. Winter temp- below -40 degrees
. Summer temp- -10 degrees to 10 degrees

Question 4

Antarctica ( 3)

Answer 4

. Colder than Arctic
. Winter temp- below -80 degrees
. Interior very dry ( less than 50mm perception)

Question 5

Polar climates makes human occupation difficult (3)

Answer 5

. Agricultural productivity is low, so traditional life style is based on subsistence farming

. Arable farming isn’t possible because few plants can survive the cold temps and frozen grounds ( so Arctic diets are normally meat based)

. Work and constructing buildings is difficult due to frozen grounds

Question 6

People living in Arid regions Affected by the climate

Answer 6

. Agriculture is impossible in most areas because rain only falls infrequently in the form of conventional rainstorms ( can cause flashy floods )

. native people are nomadic ( allows people to graze despite the sparse vegetation)

Modern irrigation techniques include drip irrigation ( hydroponics )

Question 7

Climate change has impacted agriculture (4)

Answer 7

. Climate change decreasing agricultural productivity ( due to reduced rainfall in some areas )
. Agricultural productivity can increase in other areas
. There may be changes in the types of crops grown
. Agricultural pests may increase in some areas

Question 8

Water logging

Answer 8

. Causes:
- precipitation is higher than évapotranspiration
- too much irrigation

Problems for agriculture:
- plant roots are surrounded by water, which limits their growth and can rot them
- water decreases soil temp which can reduce crop growth

Management strategies:
- Avoid over watering crops
- drain the soil using underground pipes or ditches
- change composition of the soil like sand or clay

Question 9

Salinisation

Answer 9

Causes:
- in dry conditions, there isn’t enough rainfall to leach salts away
- irrigation water contains salts - when water evaporates or absorbed by plants, the salts are left behind

Problems for agriculture
- salt can stop crops from absorbing the water
- some salts are toxic to plants so they may reduce yield

Management strategies
- avoid water logging
- only use as much water for irrigation as is needed ( drip irrigation )

Question 10

Structural deterioration

Answer 10

Causes:
- use of heavy machinery or trampling by livestock or people can compact soil
- salinisation in clay soils, as salt causes clay particles to clump together

Problem with agriculture
- land is hard to plough
- if soil is too compacted, it’s difficult for plant roots to grow

Management strategies:
- avoid salinisation
- avoid soil compaction by moving livestock regularly

Question 11

Zonal soils

Answer 11

. Soils are formed from a combination of materials from weathered bedrock and organic matter

. Mature soils that have been developed by interaction between climate and
vegetation

. Different parts of the world have different dominant zonal soil types e.g. podzols and latosals

. Soil types can be identified through distinct layers ( horizons)- 5 main ones

Question 12

Podzols

Answer 12

. Cool temp climates in northern hemisphere
. precipitation> évapotranspiration
. Coniferous woodland and heather Moorland
. O horizon is layer of loose organic matter and below is A horizon ( acidic). Nutrients are leached from A horizon by water
. Leaching of iron and aluminium creates E horizon forming quartz sand and silt
. Minerals accumulate in the B horizon forming red/ brown layer ( very well developed podzol e.g hard pan)

Question 13

Podzols not good for agriculture

Answer 13

. Arable farming is difficult:
- acidity and lack of nutrients mean that few crops are able to grow
- formation of hard pan can prevent water draining, making it vulnerable to water logging ( damaging crops )

. Forestry is common human activity in this soil type. Low temp mean that it can take up to 100 years for tree to reach maturity

Question 14

Latosols

Answer 14

. Tropical rainforest
. High temp and humidity encourage weathering of bedrock
. O horizon is thick, however as soon as it decomposes to humus, it’s nutrients are absorbed by vegetation rather than staying in soil ( so Fertile A horizon is very thin )
. Precipitation > évapotranspiration causing soil water surplus. This can result to a lot leaching from B horizon, but iron and aluminium is left behind

Question 15

Latosols influence human activities

Answer 15

. Deforestation= soil has no protection from heavy rainfall, so leaching increased

. Slash and burn clears one small area at a time

. Burning vegetation adds nutrients to the soil

. Large areas of land is Cleared for agriculture so soil doesn’t haves time to recover fully- soil degradation

. Laterite horizon is soft when it is moist but hard when dries out- useful for building

Question 16

Soil more vulnerable to erosion

Answer 16

. Clearing vegetation- rain falls directly onto the soil instead of being intercepted by plants. Vegetation also slows down the wind so removing it exposes the ground surface to stronger wind

. Topography- soil is more likely to be washed down a steep slope

. Climate- high rainfall increases water erosion

. Land use- ploughing loosens soil and exposes it to the wind and rain

Question 17

Management strategies

Answer 17

. Crop rotation- instead of leaving fields bare, farmers can plant crop covers which helps maintain the soil until a crop is sown again

. Windbreaks- trees can be planted around fields as barriers against wind erosion

. Contour ploughing- plough across the slope instead of downslope( slope ploughing) decreases soil erosion and runoff