Population and the Environment Flashcards
What is waterlogging?
When spaces in between soil particles are filled with water.
What are the causes of waterlogging?
Soils with few airspaces E.G. clay
Too much irrigation
Precipitation is higher than evapotranspiration
How does waterlogging cause problems for agriculture?
Limits the growth of plants E.G. To much water and soil temperature decrease.
The land is hard to plough
Crops are Out-competed by weeds
Management Strategies for Waterlogging
Avoid overwatering crops
Drain the soil of access water
Change soil composition
What is Salinisation?
The build-up of salts in the soil
Causes of Salinisation
High temperatures
Low precipitation levels to wash away salts
Irrigation water and some fertilisers contain salts
How does salinisation cause problems for agriculture?
Salt stops the absorption of water
Salts are toxic
Management strategies for Salinisation
Avoid waterlogging
Manage fertiliser amounts and types
What is Structural Deterioration?
Pore spaces in the soil are lost
Causes of structural deterioration
Heavy machinery
Trampling can compact soil
Salinisation may cause particles to ‘clump’
How does structural deterioration cause problems for agriculture?
The land is hard to plough
Difficult for plant roots to grow
Reduced capacity of water
Management strategies for structural decomposition
Avoid Salinisation Rotational Grazing (Movement of livestock) Maintain vegetation cover
What are the global commons?
Areas of land that are not owned by any country or organisation. They are governed by different sectors of international law.
Examples of the global commons
Antarctica
High Seas
Outer Space
Earths Atmosphere
Global Commons and NGO’s
NGO’s aim to protect the global commons from exploitation E.G. Tragedy in the Commons.’
Tourism and Antarctica
Increases shipping and air travel Disturbs breeding colonies Waste disposal 1980's tons of water being produced Increases Pollution Damaged Vegetation Introduce non-native species
Management of tourism in Antarctica
International Association of Antarctic tour operators -1991 -Limits the number of ships Marine Pollution scheme (MANPOL) -2009 -Bans heavy and intermediate fuel oils -shipping Protocol on Environment Protection to the ANarctic Treaty -1991 -environment
What is the carrying capacity?
The largest population that a country can support
What is the population ceiling?
The maximum number of people who can be supported by available resources
What factors affect carrying capacity?
Water
Shelter
Adequate food
What factors affect population growth?
Immigration (Living permanently in a foreign country)
Birth + Death Rate (Natural Change)
Emigration (Leaving one’s own country to settle in another)
Global food consumption
Consumption per person has been increasing globally
N. America - >3539kcal
S. America - <2546kcal
Global Food production
Production has been increasing since 1965 to keep up with the demand for food.
Technological Advantages lead to more food produced from less land.
DRC (Africa) - <2.8 million tonnes
North America - >410 million tonnes
