Chapter 7 Land SupplyLand as a scarce resource - Land is important resource for us to meet our basic needs for food and shelter. Eg. Land uses – grow crops, build houses and roads, set up industries - Population growing rapidly, increase demand of land for housing, farming, building of industries. - Limited amount of land in each country and scarcity of land or shortage of land cause us to have limit to amount of land we can develop - Land constraint. - “Population grow” and “Land needed for our needs” so “Demand for land rising” but “Land shortage” and “Land limited” , leading to “Land constraint” - Countries with this problem must find ways to increase land supply and use the land in best possible way to meet needs of people. - Land supply is fixed, limited or sometimes inhabitable so shortage of land.Reasons for land constraints1. Rising demand for land - Population growth needs more land for agriculture, housing, transport, water and factories. - Population growth Rapid population growth cause more land needed for human activities. All areas have carrying capacity (carrying maximum number of people in an area comfortably without straining supply of resources for future use). When people increase, available resources are shared among more people, adding pressure to the land. - Increasing demand for housing Growing population leads to increase in demand for housing. More land needed to build houses for people. Eg. New house estates developed in Singapore Punggol and Sengkang to meet increasing demand for housing. - Growth of industries The need to provide jobs for growing population is important concern for countries around the world. By developing more manufacturing industry and business, more jobs created. Eg. In Singapore, manufacturing industries take up over 10 percent of Singapore’s total land area. To expand these industries more land is needed. - Development of transport systems As country develops, more roads and railways have to be built.
Good transport network important for movement of goods and raw materials and for workers to travel between home and workplace. Eg. In some city, over 20% of total land area is used for transport facilities like roads, railways and car parks. - Increasing demand for arable land < flat land – relief > To produce food to feed increasing population, country needs more arable land. Arable land - suitable land for growing crops Arable land in short supply. Eg. Four fifth of earth land surface is unsuitable to grow crops because it is too hot, too cold, too dry or infertile. - Increasing demand for recreational spaces More people need more recreational spaces for wide range of facilities ranging from swimming pool to golf course and theatres. Some land set aside for parks and nature reserves for people to enjoy and relax in.2. Limited supply of land - Land only 30% of land surface and many not readily available for use. - Areas like swamp, marsh, low-lying coastal areas are constantly water-logged or flooded with water and desert too dry and hot to be used. (Not arable) - Land can also be damaged through mining or poor farming practices. (Not useful if left in original state ) - Even if land suitable for human use, some are reserved for military purposes or collecting water. Eg. Collect water – water catchment area, areas of forest to collect and channel rainwater into reservoirs Eg. Military purpose – training area for soldiers Eg. In Singapore, half of total land set aside for military and water collection purposes so only left limited land for industry and housing.Responses to Rising demand for land - Rising demand for limited land leads to competition between groups of people and people will have to decide the use of the land. - If land used in one way, not possible for another purpose. Eg. If a land used for natural reserve, cannot build more houses. - The cost of not being able to use the same piece of land for the next best use is called opportunity cost. Eg. Opportunity cost is not having more land for housing. - Land constraint need to be managed properly or will have problems. Eg. Increased competition cause conflict between different groups of people as some may not be able to use the land as intended. - Responses to rising demand for land : Increasing price of land , increasing supply of land , conserving land
- Increasing the price of land Land area available for use in country or city (also called supply) is limited. When demand increase, available land area (supply) cannot meet with increase in demand, price of land may increase. Some users willing to pay higher for available land and this push up the price of the land. They way prices for goods and services are set based on their demand are called price mechanism. Eg. In central Tokyo, rent of one bedroom apartment cost more than $1600 a month because the land in city area is in high demand for limited supply of land and usually very expensive. Increasing price of land is one way to tackle rising demand for land as it discourage some people from using land, thus reducing demand.- Increasing the supply of land ( Land clearance, Land reclamation , maximizing use of existing land) Land clearance To increase amount of land to meet with demand Fastest and easiest way Process whereby empty plots of land are created for various land uses Carried out by demolishing old buildings or by clearing forest (deforestation) Effectiveness – when a piece of land cleared, it can be developed for other uses. Eg. Old buildings cleared or forest demolished free up land to build new buildings and facilities. Negative impact – during deforestation, habitats of animals and plants destroyed and some of them may die while some even become extinct. This leads to negative consequences for the entire food chain. Land reclamation Increase land supply by creating dry land from area covered by water Eg. Swamp, lake or sea Process of recovering land that is damaged or abandoned to make it usable again Common ways : landfill , empoldering , reclaiming derelict land Effectiveness: Many countries successfully increase land area through land reclamation but there are limitations to how much more land country can reclaim. 1. Current technology only allows reclamation up to 15m high. Cost a lot more for deeper waters because more sand needed to fill area. Problem worse if not enough sand in country and need to obtain somewhere else. Buying sand increase overall cost. 2. for countries surrounded by others, there is limit to amount of land that can be reclaimed because cannot extend too far out into sea without entering neighbor’sterritories. There is also limited sea space for shipping activities. Negative impact on environment: coastal habitats (Eg. Mangrove swamps, beaches) destroyed by land reclamation, marine life and birds living in them affected.
Land fill Create dry land from swampy areas, marshes , and shallow parts of the sea The areas are drained and filled with material (Eg. Sand) to form dry land Stages : 1. Columns of sand called piles are forced into the soft clay of the seabed to make it more stable. (Using machines) 2. A sand wall is built around the area to reclaim to keep sea water out. Sand is loaded into the sea outside the wall to be stored until further use. (Using boat) 3. The sand previously loaded into the sea is sucked and pumped into the enclosed area. (Ships spread the sand in enclosed area while boat with machine sucks sand) 4. The sand is compressed by rollers and a granite wall is built on the side facing the sea to prevent the area from being eroded by waves. 5. Tress and other vegetation are grown or planted on reclaimed land to prevent soil erosion and land is left to rest. The number of years the land needs to rest depends on how this land will be used. Singapore is an example to use landfill to reclaim land. Empoldering Method of reclaiming land from sea Involves use of polders , also a way to control floods Polders – piece of land in a low-lying area that has been reclaimed from a body of water by building dikes and drainage canals. Usually carried out in low-lying coastal areas but can apply to further inland such as lakes Common in countries that lies below sea level and is prone to flooding Eg. Netherlands one fifth land is reclaimed from sea. Most successful project called Zuider Zee. Polders features: enclosed by dikes to keep sea or river water out, dikes protect polder from erosion, continually maintained by systems of drainage canals and pumps to prevent them from becoming water-logged. (suitable for cultivation) Stages : 1. Dike constructed around area to be reclaimed to keep water from coming in. 2. Area drained using pumps and drainage canals. 3. Reeds, a type of plant are sowed by aircrafts to help soil form 4. After 3 years, reeds are burnt and fertile ash act as fertilizers for the soil. 5. After up to 15 years, polder ready for growing crops, building houses and constructing roads. Reclaiming derelict land Natural disasters (Eg. Forest fire, severe floods) or human activities can cause damage to land. The land will then be no longer useful for certain activities. Damaged land is known as derelict land. Causes : 1. Improper farming practices
Eg. Fertility of arable land can be lost through poor farming practices. As crops grow, they take up nutrients from the soil. Different harvests of crops are grown too quickly after one another and insufficient time for soil to regain nutrients, hence losing soil fertility. Eg. Excessive ploughing of land cause large amount of soil erosion as soil structure loosens, making it prone to erosion by water. Nutrients are lost and soil no longer suitable for cultivation. 2. Mining activities While mining an area for mineral ores, vegetation and soil have to be removed because minerals are found in the ground. Enormous holes are dug and form dangerously deep mining pools when they become filled with rainwater. Heaps of mining waste is left behind and it produces poisonous substance that contaminates soil. Reclaimed by : 1. Making it arable again Eg. When derelict land form due to poor farming practices,fertilizers can be added to the soil to restore nutrients removed. 2. Clearance Eg. If by mining activities, damage greater and more work needed. Waste heaps need to be leveled out and mining pools filled. Chemicals used to treat contaminated soil and new vegetation planted as protective cover against soil erosion. After reclaim : Mining land can be used for agriculture, industry, housing, and recreation. Eg. Mine restored for recreation – Malaysia Sunway Lagoon Theme Park Maximizing use of existing land Making full use of land Improvements in technology allow people to live in environments that were previously unsuitable for living. Land use maximized as land not suitable before can now be used to build houses or used for agriculture. Maximizing urban land use In urban areas, popularity density very high so great competition for land. Mixed land use : Result of land use planning Land use planning – process by which different areas on a piece of land are assigned different land uses Traditionally, cities are planned on ones and each zone one function. (Eg. Industrial, commercial, housing, leisure) People travel long distances in order to get from one zone to another.
In order to allow for land to meet needs of more users, countries develop mixed land use projects where combination of shopping malls,offices,houses, hotels in one area. Various land uses are usually packed in a small area, linked by pedestrian walkways and escalators. In London and Singapore, this project developed in small scale. Eg. Singapore – Suntec City (offices, shops, hotels all within walking distance of one another) Advantages – 1. Many facilities located within walking distance so people enjoy convenience of having homes, jobs, wide range of services within same area. 2. Variety of activities carried out within area meet needs of more users, thus maximizing urban land use. Disadvantages – 1. In many cities, creation of mixed land use areas require much construction and reconstruction of new and old building and transport network. Can be costly. 2. Locating residential areas close to other functions (Eg. Industries, shopping areas) may lead to traffic congestion, noise and air pollution due to increased amounts of human and vehicle traffic. High density building : Technology advances over years enable taller buildings constructed where land in scarce and in high demand. These areas are high density areas because there is too many people working or living per unit area. Eg. HDB in Singapore plan to build 30 storeys or more in order to maximize land use. Most of the flats located in more established housing estates. (Eg. Bishan, Toa Payoh, close to city centre like Tanjong Pagar) Advantages – 1. More people can work or be housed in small piece of land. This frees up scarce land for other use. (Eg. Conservation as nature reserves or military training areas) 2. Helps reduce rate at which country’s remaining green space developed. Disadvantages – 1. Large number of people in small area results in crowded environment, traffic congestion; higher noise levels that increase stress level among people and reduce quality of their life.Maximizing agricultural land use Look for land to grow more food crops to feed increasing populations. Irrigation :
Watering of crops by artificial means , allow farmers to grow crops in areas with water shortage , and ensure their crops receive just the right amount of water Water channeled through irrigation pipes from certain water source (Eg. River , lake , places to where water is scarce) Advantages – 1. Ensures regular supply of water, allow farmers to grow greater amounts and wider variety of crops. 2. Maximize the use of land as area previously unsuitable for cultivation is now made arable. 3. Computerized irrigation system water plants automatically and efficiently, reducing need for human labor. Disadvantages – 1. If not proper maintains, irrigation canals can hold stagnant water and lead to breeding sites for bacteria, mosquitos and other pest. 2. With poor drainage, irrigation causes land to become water- logged and damage crops. 3. River water used for irrigation contain large amount of dissolved mineral salts that damage crops. 4. Can be expensive to construct especially if a dam needs to be built across a waterway to make a reservoir. Terracing : Arable and flat land limited (Eg. Japan). Hilly areas unsuitable for farming because of steep slopes cause water to run off the slopes very quickly and very little water retained in soil and plants will not grow well. Rain also erode soil and wash away nutrients and plants not enough water or nutrients to grow well. Difficult to operate modern farm machinery on steep slopes. Cultivation on slopes made possible by terracing. Terracing – involves creating flat strips of land by cutting series of steps into hill slopes. Increase supply of arable land as flat land more favorable for cultivation. Characteristic: low walls built at end of each step, walls called bunds help to slow down runoff of rainwater so it can seep into soil and absorbed by plant roots, walls of terraces hold water in enclosed area and created flooded conditions needed for growing crops (Eg. Padi) Advantages – 1. Inexpensive method of increasing area of arable land 2. Bunds used in terracing prevent soil from being washed away 3. Strips of flat land created by terracing also make it possible for modern machinery to be used, making farming more efficient Disadvantages –
1. Terraces are hard to construct and a lot of human labor, energy, time needed to cut steps into hill slopes 2. a lot effort needed to maintain terraces after they are constructed. If bunds damaged, they may not hold the soil back, resulting in soil erosion. Soil-less farming : Maximize land for agriculture by growing crops without soil Enable crops to be grown closer together , maximizing land use for agricultural purpose Without soil agriculture – soil-less farming Eg. Hydroponics, aeroponics Advantages – 1. Plants grown by soil-less farming can be grown closer together and more crops can be grown on a single area of land at the same time. 2. Found to be effective in increasing output of crops as sufficient nutrients is delivered and distributed evenly at regular intervals. The controlled conditions also prevent growth of weeds or insects. Disadvantages – 1. Farmers must invest in high technology equipment and specially prepared nutrient solution for plants which may be too costly for farmers without enough funds. 2. May not be practical in countries where farmers do not receive enough training to enable them to operate high technology equipment- Conserving Land As country develops, demand for land to build house, industries and other facilities will naturally increase. While these developments benefit people, country’s forest and other nature areas should be protected. Government need to make plans for conserving land. Conserving land – careful use of land resources to ensure that damage is kept to the minimum One way to conserve land is to set aside land as nature reserves where land is carefully managed to protect wildlife , plants , other natural features and provide special opportunities for study or research Eg. In Singapore, 5% of total land area is set aside as nature reserve. Eg. Sungei Buloh Wetland Reserve located at northwestern coast of Singapore. Home to 126 species of birds only found in the area and protected for its natural heritage. .