Land

Reasons for land constraint


-Population growth

-Increased demand for housing

-Growth of industries

-Development of transport systems

-Increased demand for arable land

-Increased demand for recreational spaces

With a high population growth, people would need more places to stay. Hence, land has to be used for housing purposes. Growth of industries will provide people jobs thus, land is needed for industries to be built. Development of transport systems is crucial for an urbanised country, land is also needed for this. Food is needed to feed the population. Arable land is hence needed to grow crops. Land for recreational activities is also needed to provide a place for people to relax.

Limited supply
Only 30percent of the Earth is made up of land, and not all can be used. This is so as some land are swamps, marshes and low-lying coastal areas, that are constantly waterlogged or flooded with water, while deserts are too dry for human usage. Land can also be damaged by mining or poor farming practices.

Some land can also be reserved for certain uses, like water catchment areas and military training areas.

Methods to combat the rising demand for land

Increase the price of land
By doing this, people may not be willing to pay such a high price for the usage of land. Hence, discouraging people from using the land thus, reducing demand.

Land clearance
This is by increasing the amount of land available for development. A way to do this is by deforestation.
Deforestation can however cause loss of habitats for animals, thus leading to negative effects for the entire food chain.

Land reclamation

1. The creation of dry land from an area covered by water
2. Process of recovering land that is damaged or abandoned and making it usable again

1.LANDFILL
The landfill method is used to create dry land from swampy land areas, marshes and shallow parts of the sea. These areas are drained of water and filled with materials such as sand to form dry land.

STAGE 1:Columns of sand known as piles are forced into the soft clay of the seabed to make it more stable. Piles support the sandwall so that sandwall will not sink

STAGE2: 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.

STAGE 3: The sand previously stored outside the sand wall is sucked up and pumped into the enclosed area.

STAGE 4: The sand is compressed and a granite wall is built on the side facing the sea, to prevent water from eroding the sand wall.

STAGE 5: Trees and vegetation will be grown on the reclaimed land, 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.




2. EMPOLDERING


This method is a way of reclaiming land from the sea. It is carried out in low lying coastal areas but can also be applied to inland areas, such as lakes.

STAGE 1:A dike is constructed around the area to be reclaimed to keep water from coming in.

STAGE 2:The area is drained using pumps and drainage canals

STAGE 3:Reeds, is sown by aircraft to help the soil form. This is so as nutrients has dissolved in the sea water.

STAGE 4:After 3 years, reeds are burnt and the ash is used as fertilisers for the soil.

STAGE 5:After a period of 15 years, the polder is ready for agriculture and the building of houses and roads.


3. DERELICT LAND
Caused by improper farming practices and mining activities.

Improper farming activities
Derelict land happens when the different types of crops take up nutrients too quickly from the ground, thus resulting in the loss of soil fertility.


Excessive ploughing of land will also cause the land to be derelict. This is due to the soil structure getting loosened , thus resulting in soil erosion by water. During this, nutrients is lost and the soil is no longer arable.

Mining activities
In the process of mining, mineral ores,vegetation and soil have to be removed because the minerals are found in the ground. Huge holes are dug into the ground, thus forming dangerous deep mining pools when they are filled with rainwater. Heaps of mining waste are also left behind. This waste may contain poisonous substances that contaminate the soil.

Reclaim derelict land
When land is damaged due to poor farming practices, fertilisers can be added to the soil to make it arable again.

When land is damaged due to mining activities, waste heaps needs to be leveled out and mining pools need to be filled. Chemicals then can be used to treat the contaminated soil. New vegetation can also be planted to act as a protective cover against soil erosion.

Reclaimed mining land can be used for many purposes including agriculture, recreational and housing.

Effectiveness of land reclamation
The cost of land reclamation is high. For example, the landfill method only allows reclamation of up to 15m in depth. Any higher than that and the cost will be high as more sand is needed. This is especially so when the country does not have enough sand from inland.

Land reclamation has its limits as countries have territorial boundaries. Countries like Singapore, cannot extend land too far out into the sea without entering the neighbour's territorial.. Sea space also needs to be kept for trading activities.

Land reclamation will also destroy habitats of marine animals that live in reclaimed areas.


Maximise land use
Besides reclaiming land, countries can also make full use of existing land.

Mixed landuse
Where there is a combination of shopping malls, offices, houses and hotels all within walking distances of each other.

Advantage:People can enjoy the convenience of having everything all in one area. The variety of activities carried out in one area, can meet the needs of more users and hence, help to maximise urban landuse.
Disadvantages: Construction and reconstruction of new and old buildings and transport networks can be costly. Due to the close proximity of buildings and services, traffic congestion may lead to noise/air pollution because of the increased amount of human and vehicle traffic.

High density building
Taller buildings are to be constructed in areas where land is scarce but in high demand.

Advantages: Many people can work or be housed on a small piece of land. This frees up scarce land for other landuses. High density building also helps reduce the rate at which the country's remaining green spaces are developed.
Disaadvantage: This may result in a more crowded environment, traffic congestion and higher noise levels, hence, leading to increased stress levels and reduced quality of life.

Maximise agriculture landuse

Irrigation
Watering of crops through artificial means allows farmers to grow crops in areas that experience water shortage, and to ensure that crops receive just the right amount of water. Water is channeled from irrigation pipes from water sources such as lakes and rivers, to a place where water is scarce.

Advantages: 1.Ensures a regular supple of water, hence, allowing farmers to grow greater amount and wider varieties of crops.
2. Maximises the use of land as areas are made arable throughout the year.
3. Computerised irrigation systems can water plants automatically and efficiently, reducing the need for human labour.

Disadvantages: 1.If not properly mantained, irrigation canals can hold stagnant water which may become breeding sites for bacteria, musquitoes and other pests.
2. With poor drainage, irrigation may cause land to be waterlogged, causing damage to crops,
3. River water that is used for irrigation may contain high amount of dissolved mineral salts, which can cause damage to crops.
4. Irrigation systems can be expensive to construct, especially so when a dam needs to be built across a waterway to creat e a reservoir.




Terracing
Cultivation of crops on hilly areas is bad as rain erodes the soil and washes away the nutrients more easily than on flat land. Little water is also retained in the soil. Hence, terracing, which involves creating flat strips of land by cutting a series of steps into hill slopes, thus increasing the supply of arable land. Low walls are also built to slow down the runoff of rainwater so that it can seep into the soil.

Advantages: 1. Terracing is inexpensive.
2. Bunds used in terracing prevent the soil from being washed away.
3. The strips of flat land makes it possible for modern machinery to be used, thus making farming more efficient.

Disadvanatages: 1.Terraces are difficult to construct and a lot of energy and time is needed to cut steps into hill slopes.
2. A lot of effort is needed to maintain the terraces after they are constructed. If the bunds are damaged, they may not be able to hold the soil back, hence resulting in soil erosion.

Soil-less farming
Growing crops without soil enables crops to be grown closer, thus maximising landuse for agricultural purposes. An example of this is, hydroponics and aeroponics.

Advantages: 1. Plants growing without soil can be grown closer together, hence, increasing output per land area.
2. Effective in increasing output of crops. Sufficient amounts of nutrients can be delivered and distributed at regular intervals. Weeds and insects are prevented as crops are grown in a controlled environment.
Disadvantages: 1. Expensive way of farming due to expansive technology and nutrient solution.
2. May not be practical in countries where farmers do not receive enough training to enable them to operate high technology equipment.

Reflection

Learning this chapter on land, is crucial as Singapore has a scarcity of land. Due to high population growth, Singapore has to keep thinking of alternative and efficient methods, to combat land constraint. Land in the world is also scarce. Hence, the methods to prevent land erosion and to reclaim more land can help us solve this problem. For example, in Singapore, breakwaters are build in coastal areas, to prevent coastal erosion. Hence, the younger generation should study this topic as they are the future leaders of our world and would need to tackle this problem.

-Samantha lye