Population And Environment Flashcards
How does climate affect population density?
Temperature climates are more favourable to live in,
certain types of agriculture require different climates,
Extreme climates can’t support human life
How does soil affect population density?
Soil will affect the amount of and variety of crops that can be grown
How will topography affect the population density?
Mountainous areas are hard to build on
How will hazards affect the population density?
People are less likely to move into areas that have a hazard risk,
Old cities were built without knowledge of plate tectonics,
Hazard areas can be cheaper to live in
Stage 1 of DTM
High birth rate,
High infant mortality,
High death rate,
Lack of healthcare and poor hygiene
Stage 2 of DTM
High birth rate,
Low death rate,
More healthcare and hygiene
Stage 3 of DTM
Lower birth rate,
Death rate continues to fall,
Socio economic development
Stage 4 of DTM
Low birth rate and death rate,
Population levels are still high
Stage 5 of DTM
Birth rates fall even lower (different life aspirations)
Death rate evens/ increases due to an ageing population
Advantages of the DTM
Provides insight to when a country’s population has changed,
There is no time limit,
Easy to understand,
Simple to draw conclusions
Disadvantages of the DTM
Some countries don’t let the population naturally change,
Knowledge of disease prevention has improved,
Model presumes countries won’t regress,
Outside impacts on population change (migration)
Doesn’t show impact on the natural environment
Definition of overpopulation
When there are too many people living in an area relative to the amount of resources and technology available locally to maintain a high standard of living
Catergorised by low per capita income, high unemployment and outward migration
Definition of underpopulation
This occurs when there is too little people in an area to use the resources and technology effectively
An increase in population would mean the resources are more effectively used and the standard of living improves
Definition of optimum population
The theoretical population which, working with all the available resources, will produce the highest standard of living for the people of the area
This concept is dynamic; when technology improves and more resources become available which means more people can be supported
Why are the Andes and the Himalayas sparsely populated?
Rugged mountains and low temperatures
Why is Iceland sparsely populated?
Active volcano
Why is Northern Canada and Russia sparsely populated?
Too cold to support large amounts of crops/vegetation
Why are The Netherlands and Bangladesh densely populated?
Flat, lowland areas are easy to grow/build onto
Why are the Ganges densely populated?
Highly fertile soil
Why is North West Europe densely populated?
Areas of reliable rainfall, lots of water
Definition of food security
When people have enough affordable and nutritious food to eat
What % must food supply increase by in order to meet the demand by 2030
50%
How much arable land on Earth has been lost in the last 40 years?
A third
What continent does most of the worlds food come from?
Asia
Which countries are the largest producers of meat and fish?
China and India
Definition of double burden of malnutrition
High income countries consume more processed foods (more disposable income) which makes people fat but does not give them a nutrient rich diet
In low income countries a lack of calories and nutrients (lack of money for any food) causes starvation and malnutrition
Physical inputs of an agricultural system
Climate, rain, length of growth season, temperature, relief, soils and drainage
Human inputs in agricultural systems
Labour, rent, transport, machinery, fertiliser, seed, buildings, energy and market demand
Processes in an agricultural system
Jobs on the farm, ploughing, weeding, harvesting
Positive outputs of an agricultural system
Products, crops, animals and animal products (milk, wool, meat)
Negative outputs of an agricultural system
Pollution, soil erosion, eutrification, unused products
How are the outputs of an agricultural system used in LICs?
Consumed by the farmers and their family
How are the outputs of an agricultural system used in HICs?
Output profit reinvested into improvements for the farm, generally to make it more efficent
Physical changes to the agricultural system
Floods, disease (eg, foot and mouth)
Human changes to an agricultural system
Change in demand, change in market price, or change in government policy
Definition of sedentary farming
Permanently in one place
Pros of sedentary farming
Stability
Cons of sedentary farming
Soil can be damaged,
Can’t relocate it the climate dramatically changes
Definition of nomadic farming
Moving, farmers move to new locations a lot
Pros of nomadic farming
Maintains the soil fertility
Cons of nomadic farming
Not stable or reliable
Definition of subsistence farming
Crops grown just for the farmer and his family to be able to live
Pros of subsistence farming
Less money to spend on food in LIC
Cons of subsistence farming
The family will struggle if anything goes wrong
Definition of commercial farming
Grown to sell
Pros of commercial farming
Large profits used to improve efficiency of farm
Cons of commercial farming
Large environmental impact
Definition of arable farming
Crops
Pros of arable farming
Large yield, making them cheaper
Cons of arable farming
Effected largely by climate
Definition of pastoral farming
Animals
Pros of pastoral farming
More variety of products to sell
Cons of pastoral farming
More costly than arable
Definition of mixed farming
Crops and animals
Pros of mixed farming
If crops fail, animals can replace the lost profits
Cons of mixed farming
Lots more money and labour to maintain
Definition of extensive farming
Low inputs of labour or capital
Pros of extensive farming
Lots of money can be made for little effort
Definition of intensive farming
High inputs of labour and capital
Pros of intensive farming
Large yields
Cons of intensive farming
Costly
Definition of GM farming
” Genetically modified” involves inserting and changing DNA in order to produce more desirable yield
Pros of GM farming
High yields of aesthetically pleasing crops which people are more likely to pay for
Cons of GM farming
More expensive to produce, people stop buying “wonky” crops
Definition of organic farming
No synthetic material or alteration
Cons of organic farming
More expensive
Why do different types of farming occur in different parts of the world?
Wealth and resources, soil and climate conditions
Conditions needed to grow rice
High rainfall,
High temperatures (16 - 27 C),
Alluvial soils are ideal because it retains lots of water needed to grow rice
Conditions needed to grow potatoes
Less water,
Lower temperatures (18 - 20C)
Lose sandy soils are ideal because they easily allow roots to grow through the soil to find water and nutrients
Peri-urban horticulture
Offers the urban poor a buffer against food price increases and economic upheaval,
Associated with greater dietary diversity and higher calorie availability,
50% of households are involved in UPH in Latin America
Causes of the Irish potato famine
Failure of the potato crop,
Disease which destroyed leaves and roots,
Between 1845 and 1849
Impacts of Irish potato famine
Population decrease of 2.2 million,
1 million deaths,
100,000 farmers were unable to pay rent and were evicted,
Population was half of what it was in 1920
Importance of the potato in Ireland
Calorie dense,
Easily grown in Irish soil,
Half of Irish population relied exclusively on potatoes,
Typical cottier family consumed around 8 pounds of potatoes per person per day
How did the potato blight of the potato famine occur?
Small genetic variation of plants,
A strain of water mould arrived from North America,
Cold and moist weather allowed the mould to thrive,
Destroyed potatoes between 1846 - 1849
How many people died in the Irish potato famine?
1 million deaths from starvation,
2 million people moved out of Ireland
Location of semi arid climates
Between the tropics,
Alongside desert regions,
North and South America, Africa, South Asia and Australia
Characteristics of semi arid climates
Extremely dry,
Distinct wet season,
25 - 50 cm of rain per year
Importance and type of agriculture in semi arid climates
Pastoral (sedentary and nomadic), rainfed and irrigated mixed farming,
Unreliable farming causes food insecurity and malnutrition is common,
Sheep, goats and camels
Millet, cowpea and cotton
Threats to semi arid climate zones
Lack of rain season,
Fires commonly destroy grass,
Decrease in rainfall,
Droughts,
Malnutrition,
Overpopulation
Location of Mediterranean climates
Between 30 - 45 latitude,
Parts of Europe (Italy and Greece), South Africa, West America (California)
Characteristics of Mediterranean climate zones
Warm and stormy winters (occasional snow),
Hot and dry summers,
50 cm rain per year
Characteristics of vegetation in Mediterranean climate zones
Waxy leaves, shallow roots, shrubs and thorny bushes
Importance and type of agriculture in Mediterranean climate zones
No pastoral farming, as there is no grazing land,
Agriculture in these areas generate tourism,
Olive trees, cork oak trees, grape vines and figs
Threats to Mediterranean climate zones
Growth of hotels and resorts (loss of water resources)
Wild fires (especially dangerous for cork trees which have had their cork/bark harvested)
Mediterranean Sea is warming very quickly
Characteristics of zonal soils
Distinct layers,
Hundreds of years to form,
Formed from weathered rock, organic material, water and air
Layered profile, defined layers and features