Chapter 7: Land Supply
Land is a scarce resource
-enables us to meet our needs (food, shelter, etc.)
-growing crops, building houses & roads, setting up industries
___________________________________________________________
Land Constraint
-growing world population, leading to increasing demand for land (for housing, farming, etc.)
-limited land in every country, thus there is scarcity of land (land shortage)
-limit to amount of land that can be developed for different uses (land constraint)
-2 main reasons: rising demand for land & limited supply of land
1) Rising demand for land
1. Population growth
-more people, more land needed for human activities
-all areas have carrying capacity
-more people, available resources have to be shared among more people
-adds pressure to land
2. Increasing demand for housing
-growing population means more houses needed for more people
-eg. HDB flats are built to meet increasing demand for housing
3. Growth of industries
-need to provide jobs for growing population
-thus, more industries & businesses need to be developed
-eg. manufacturing industries take up over 10% of Singapore's total land area
-more land needed to expand industries
4. Development of transport systems
-more developed country, more roads & railways needed
-transport important for country
-eg. in some cities, over 20 of total land area set aside for transport facilities
5. Increasing demand for arable land
-needed to produce food to feed increasing populations
-arable land is in short supply
-over 4/5 of earth's land surface unsuitable for growing crops
6. Increasing demand for recreational spaces
-more people, more recreational spaces needed
-eg. swimming pools, parks, etc.
-for people to enjoy & relax in
2) Limited supply of land
-30% of earth's surface, only part the 30% is available for use
-areas unsuitable for use or of little use (eg. swamps, marshes, low-lying coastal areas, deserts, damaged land due to mining/poor farming practices, etc.)
-land reserved for other uses (eg. water catchment areas, military purposes)
-eg. military training areas & water catchment areas in Singapore take up more than 50% of
total land
__________________________________________________________
Responses to rising demand for land
-increased competition between different groups of people
-decisions on how pieces of land are to be used
-opportunity cost: cost of not being able to use same piece of land for next best use
-eg. opportunity cost of having a nature reserve is having less land for housing
-thus, land constraint must be managed properly
1) Increasing the price of land
-increased demand, increased price
-some users may be willing to pay higher price for available land, thus leading to increased price
-price mechanism: way in which prices for goods & services are set based on demand & supply
-eg. land in city area is usually very expensive. eg. it costs $1600+ a month to rent a one-bedroom apartment in Central Tokyo
-increasing price of land discourages some people from using land, thus reducing demand
2) Increasing the supply of land
1. Land clearance
-land clearance: process whereby empty plots of land are created for various land uses
-demolishing old buildings, clearing forests (deforestation)
-eg. when old buildings are demolished, more land is available to build new buildings/facilities
-negative impact on environment
-eg. deforestation destroys habitats of plants & animals
-negative consequences for food chains
2. Land reclamation
-land reclamation: creation of dry land from area covered by water/process of recovering land that is damaged or abandoned & making it usable again
-landfill, empoldering & reclaiming derelict land
1. Landfill (5 main stages)-used to create dry land from swampy areas, marshes & shallow parts of sea-areas drained & filled with sand-like material to form dry land-eg. Singapore uses the landfill methodStage 1) Piles (columns of sand) are forced into the soft clay of the seabed to make it more stableStage 2) Sand wall is built around the area to be reclaimed to keep the sea water out. Sand is loaded into the sea just outside the sand wall & stored there until neededStage 3) Sand that is previously loaded is sucked up & pumped into enclosed area.Stage 4) Sand is compressed & a granite wall is built on the side facing the sea to prevent erosion.Stage 5) Trees & other vegetation grown on the reclaimed land to prevent soil erosion. Land is left to rest. Number of years land is needed to rest depends on the usage of the land.
2. Empoldering (5 main stages)-involves use of polders (a piece of land in low-lying area that has been reclaimed from a body of water by building dikes & drainage canals)-way to control floods-commonly carried out in countries that mostly lie below sea level & is prone to flooding (eg. Netherlands)Stage 1) Dike is constructed around area to be reclaimed to keep water from coming inStage 2) Area is drained using pumps & drainage canalsStage 3) Reeds are sown by aircraft to help soil formStage 4) After 3 years, reeds are burnt. Ash is used as soil fertilisers.Stage 5) After a maximum of 5 years, polder is ready for use.
3. Reclaiming derelict land-derelict land: damaged land because of natural disasters or human activities-human activities like improper farming practices & mining activities-derelict land can be reclaimed to make it arable again-eg. fertilisers can be added to soil to restore nutrients-for derelict land because of mining activities, more work needed-waste heaps levelled out, mining pools filled, chemicals used to treat contaminated soil, new vegetation planted
-many countries successfully increased land area through land reclamation
-limitations to how much land can be reclaimed
-eg. current technology only allows land to be reclaimed from waters of maximum depth of 15m
-eg. reclaimed land cannot enter other countries' territories
-eg. negative impact on environment. coastal habitats destroyed, marine life & birds affected
3) Maximise use of existing land
1. Maximising urban landuse (Mixed Landuse)
-Landuse planning: process by which different areas on piece of land are assigned for different landuses
-traditionally, cities were planned based on zones
-now, countries starting to develop mixed landuse projects
-eg. combination of shopping malls, offices, houses & hotels in 1 area
-advantages: convenient, variety of activities in the area can meet the needs of more users
-disadvantages: costly (requires both construction & reconstruction of new & old buildings/transport networks), may lead to traffic congestion/noise & air pollution
2. Maximising urban landuse (High Density Building)
-technological advances enabled taller buildings to be constructed
-eg. in Singapore, HDB plans to build 30-storey+ flats in order to maximise landuse
-advantages: more people can work/be housed on a piece of land, frees up scarce land for other uses, reduces rate at which country's remaining green spaces are developed
-disadvantages: more crowded environment, traffic congestion, higher noise levels, increased stress levels, reduced quality of life
3. Maximising agricultural landuse (Irrigation)
-irrigation: watering of crops through artificial means
-allows farmers to grow crops in areas that experience water shortage
-ensures that crops receive right amount of water
-water channelled through irrigation pipes from water sources like rivers or lakes to places where water is scarce
-advantages: ensures regular supply of water & thus greater amounts and wider varieties of crops, maximises use of land, reducing need for human labour
-disadvantages: canals may become bacteria/mosquito/pest breeding sites, land may become waterlogged, crop damage, expensive
4. Maximising agricultural landuse (Terracing)
-hilly areas used for cultivation of crops
-terracing: creating flat strips of land by cutting a series of steps into hill slopes
-increases supply of arable land
-low walls built at end of each step help to slow down runoff of rainwater
-walls hold water in enclosed area & create flooded conditions needed for growing crops like padi
-advantages: inexpensive, bunds prevent soil from being washed away, more efficient farming
-disadvantages: a lot of human energy & time needed, high maintenance, soil erosion may happen
5. Maximising agricultural landuse (Soil-less farming)
-enables crops to be grown close together
-eg. hydroponics & aeroponics
-advantages: more crops can be grown on single area of land at the same time, increases crop output, prevents growth of weeds/insects
-disadvantages: expensive, not practical in some countries
________________________________________________________
Conserving land
-forests & nature areas should be protected
-conserving land: careful use of land resources to ensure that damage is kept to a minimum
-eg. set aside land as nature reserves
-protect natural heritage
Pae En Qi (29), Sec 2-1
0 Comments:
Post a Comment
<< Home