Land Supply

Land as a Scarce Resource

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Land is an important resource - used for various purposes to meet our

needs.

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total amount of land available in every country is limited.

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only 1/3 of the earth’s surface is land and of this, about half is covered by

mountains, deserts, ice and swamps (pp 6)

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=scarcity or shortage of land to be developed for various uses.

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= amount of land that can be developed for various uses is limited.

= Land constraint

Scarcity of land in Singapore requires careful planning to maximize

landuse

Reasons for land constraints

Rising demand for land

-Population growth

-Increasing demand for housing 

-Growth of industries

-Development of transport systems 

-Increasing demand for arable land

-Increasing demand for recreational spaces

Population growth :

-There is a rapid population growth in the last few decades, thus more land is needed for human activities.

-All areas have a carrying capacity 

-When the number of people increases, the available resources would have to be shared among more people, which adds pressure to the land 

Increasing demand for housing:

-As a result of rapid population growth in the last few decades, more and is needed for human activities .

-As a population grows, there will be increasing demand for housing

-Singapore has built high rise HDB apartments to meet the increasing demand for housing

Growth of industries:

-The need to provide jobs for a growing population, thus there is a need to develop more industries.
-To expand industries, more land is needed
-10% of Singapore's total land area is taken up by industries.


Development of transport systems:
-As a country develops, more roads and railways have to be built
-20% of the total land area in some cities is set aside for transport facilities


Increasing demand for arable land:
-to produce food to feed their increasing populations, countries have to look for more arable land
-Arable land is a short supply


Increasing demand for recreational spaces:
-With more people, more recreational spaces will have to be provided
-Eg swimming pools, public golf courses, theaters and nature reserves.


Limited supply of land

Land makes up only 30% of the Earth's surfaces. Of this, not all are readily available. For example, swamps, marshes and low lying coastal areas are constantly flooded with water, deserts are too dry to be of much use. Even when land is suitable for human use, it may be reserved for certain uses. For example, water catchment areas, training areas for soldiers etc
Therefore,theres a limited area for other purposes.

Responses to rising demand for land

Increasing the price of land 
-The land supply for every country is limited.
-Price of land increases when there is a high demand of land and people are willing to pay a higher price for the available land.
-Referred to as the price machanism
-Land in city area is usually very expensive. For example,It costs more than 1600 a month to rent a one-bedroom apartment
- Demand for land
People will be discouraged from using the land with the price of land increases.

Increasing the supply of land:
-Land clearance
-Land reclamation (Landfill, empoldering, reclaiming derelict land)


Land clearance
-Process whereby empty plots of land are created for various land uses.
-For example, demolishing old buildings or by clearing forests(Deforestation)
Effectiveness?
-Land is freed up to build new buildings and other facilities when land is cleared(Positive)
-When deforestation takes place, habitats of many plants and animals are destroyed (Negative)
       => Many plants and animals may die or even become extinct! 
                             => Effect the entire food chain.

Land reclamation
-Creation of dry land from an area covered by water
-Recovering of land that is damaged or abandoned and making it usable again


Landfill
Step 1 : Columns of sand known as piles are forced into the soft clay of the seabed to make it more stable
Step 2 : A sand wall is built around the area to be reclaimed to keep sea water out. Sand is loaded into the sea just outside the sand wall and stored there until it is needed
Step 3: The sand that was previously loaded into the sea is sucked up and pumped into the enclosed area
Step 4 : The sand is compressed and a granite wall is build on the side facing the sea to prevent area from being eroded by waves.
Step 5: Tress and other vegetation are grown on the reclaimed and to prevent soil erosion and the land is left to rest.( The number of years the land needs to rest depends on how this land will be used.)

Examples:
 

Empoldering

-Involve the use of polders 
-Also a way to control floods
-Carried out in the low lying coastal areas.
-Common in countries like the Netherlands(country that lies below sea level and prone to flooding.)


Process:
Step 1: A dike constructed around the area to be reclaimed to keep water from coming in
Step 2: The area is drained using pumps and drainage canals
Step 3: Reeds, a type of plant, are sown by aircraft to help the soil form
Step 4: After 3 years, the reeds are burnt and the ash is used as fertilisers for the soil.
Step 5: After a period of up to 15 years, the polder is ready for growing crops, building houses and constructing roads.
Reclaiming derelict land:
-Natural disasters as well as human activities can cause damage to the land
-The damaged land cannot be used for certain activities. 
-This damaged land is also known as derelict land
-2 ways in which a piece of land becomes derelict

Improper farming practices
-Fertility of the land can be lost through poor farming practices. The crops take up nutrients in the soil as they grow. There is insufficient time for the nutrients to be replaced when different harvest of crops are grown one after another.
-Excessive ploughing of land can also cause a large amount of soil erosion as the soil structure is loosened making it very prone to erosion by water. Nutrients are lost and the soil is no longer suitable for cultivation when this happens.

Mining activities
-In the process of mining ores, vegetation and soil have to be removed because the minerals are found in the ground. 
-Enormous holes are dug and deep mining pools are formed when it is filled with rainwater.
-Heaps of mining waste are also left behind and they may contain poisonous substances that contaminate the soil.


How derelict land is reclaimed ?
-Fertilisers can be added to the soil to restore the nutrients that have been removed.
-Waste heaps need to be levelled out and mining pools need to be filled.
-Chemicals can be used to treat the contaminated soil.
-New vegetation can also be planted to prevent soil erosion.

Effectiveness of land reclamation?
-Many countries have successfully increased their land area through the various method of land reclamation
-There are limitations as to how much more land a country can reclaim
-Limitations in technology(current technology only allows land to be reclaimed up to 15 m in depth)
-Cost a lot to reclaim land from deeper waters
-Cannot enter neighbours' territories when reclaiming land
-Need to keep a certain amount of sea space available for shipping activities.
-Marine life and birds that live in mangrove swamps and beaches will be affected when the area is destroyed for land reclamation


Maximise use of existing land 


Maximising urban landuse
- 2 ways to do so
   =>Mixed landuse & High density building 


Mixed landuse

-Usually a result of landuse planning

-Landuse planning is the process by which different areas on a piece of land are assigned for different landuses

-The different landuses are usually closely parked in a small area and linked by pedestrian walkways and escalators.

-Currently, mixed landuse projects are being developed on a small scale n many cities such as London and Singapore (few hectares)

Advantages:

-Facilities are within walking distance.

-People can enjoy the convenience of having their homes, jobs and a wide range of services within the same area.

-The particular area can meet the needs of many users thus help to maximize urban landuse.

Disadvantages:

-mixed landuse areas requires both the construction and reconstruction of new and old buildings as well as transport networks, which is costly!

-Locating residential areas close to other functions such as industries and shopping areas may lead to traffic congestion, as well as noise and air pollution.

High density building

-technological advances have enabled taller buildings to be constructed in areas where land is scarce but in high demand(high density area)

-HDB plans to build flats of 30 storeys and more in order to maximize landuse, in estates such as Bishan and Toa Payoh as they are more established.

Advantages:

-More people can work or be housed on a small piece of land.

-Frees out scarce land for other landuses.

-Helps to reduce the rate at which the country’s remaining green spaces are developed

Disadvantages:

-large number of people in a small area may result in a more crowded environment

-Traffic congestion and higher noise levels

-increased stress levels among people and reduce their quality life

Maximising agricultural landuse

-3 ways to maximize agricultural landuse areas

            =>Irrigation, Terracing & Soil-less farming

Irrigation

-watering of crops through artificial means, allows farmers to grow crops in areas that experience water shortage (ensure that their crops receive just the right amount of water)

-Water can be channeled through irrigation pipes from various water sources such as river or a lake to places where water is scarce.

Advantages:

-ensures a regular supply of water

-Allows farmers to grow greater amounts and wider varieties of crops.

-Maximises the use of land as areas became arable.

-Efficient, automatic and reduces the need of human labour (Computerised irrigation)

Disadvantages:

-If not properly maintained, irrigation canals can hold stagnant waters which may breed mosquitoes, other pests and bacteria

-May cause land to become waterlogged. (Damage to crops)

-River water may contain high amounts of dissolved mineral salts which can cause damage to cops.

-Some may be expensive to construct

Terracing

-Involves creating flat strips of land by cutting a series of steps into hill slopes.

-Increases the supply of arable land as flat land is more favourable for cultivation.

-Low walls are built at the end of each step(bunds) help to slow down the runoff of rainwater so that it can seep into the soil and be absorbed by plant roots

Advantages:

-inexpensive method

-prevent the soil from being washed away

-making farming more efficient

Disadvantages:

-Difficult to construct

-requires a lot of human energy and time

-A lot of effort to maintain the terraces after they are constructed

-If bunds are damaged, it may result in soil erosion.

Soil-less farming

-enables crops to be grown closer together, thus maximizing landuse for agricultural purpose.

-Eg. Hydroponics and aeroponics

Advantages:

-plants can be grown closer together

-More crops can be grown on a single area of land at the same time

-effective in increasing the output of crops

-controlled conditions also help to prevent the growth of weeds or insects

Disadvantages:

-Costly for farmers who do not have enough funds.

-Not practical in countries where farmers do not receive enough training to enable them to operate the high technology equipment

Conserving land

-Careful use of land resources to ensure that damage is kept to a minimum

-Eg. Nature reserves (natural heritage)