Secondary 2 Geography Mid-Year RevisionUnit1 The human EnvironmentThe human environment evolves when man made changes to the physical environment to carry out activities such as agriculture, industries and business. Population and SettlementsThe formation of settlements is a natural consequence of people living together. -AgriculturePeople need food to survive. People grow crops on fertile soil and rear animals on rich pastures.-Transport and CommunicationMoving fuels, raw materials, agriculture produce, and manufactured goods. Physical Environment Affecting Population And Settlements~like to live on coastal lowlands and large river valleys as these areas suitable for farming and transport links.~dense settlements are developed~fewer people live in harsh environments such as highlands, deserts and polar regionsPhysical Environment Affecting Agriculture~large river valley most attractive location for agriculture~floodplain has a flat relief fertile soil and good water supply~plains and prairies used for farming~sloped of volcanoes are rich with fertile soilPhysical Environment Affecting Transportation~rivers, coastal areas and lowlands affect the development of transportation~use rivers to move people and goods led to the development of river ports~coastal sites favour the development of sea ports~lowland ideal for constructing railway and road networkThe world population refers to the number of people living on the Earth. Factors Affecting Population GrowthPopulation growth is affected by births and deaths. The population grows when the number of births is greater than the number of deaths. This growth in population is known as natural population increase.Birth rate refers to the number of live births per 1000 people in a year. Death rate refers to the number of deaths per 1000 people in a year.Natural increase = Birth rate- Death ratePopulation Distribution~refers to the spread of people in an areaPopulation density~the population density of a place can be described as the total number of people living in a square kilometre of land.Population density =Total population[people]/Area [km2]Factors Affecting Population Distribution And DensityPhysical factors~relief (flat land)~climate (conducive temperatures)~soil (fertile soil)~mineral resources (iron or gold)Human and Economic factors~mining and industry (oil mining and steel manufacturing)~commerce (banking)~agriculture (farming)~politics and religion (stable government)~transport and accessibility (good railway system)People living in a square kilometre of land:More than 200 densely populated10~200 moderately populatedLess than 10 sparsely populatedFactors That Encourage A High Birthday Rate~Early marriages~Children are seen as wealth~High number of deaths among children~Lack of knowledge on birth control~Preference for a male child~Religious belief that do not allow the use of contraceptives Consequences of A High Rate of Population Growth~Overcrowding~Shortage of food~Pressure on social services~Unemployment and other social problemsResponses to A High Rate of Population Growth~Economic development~Birth control and family planning~Increasing the rate of literacyCauses of A Low Rate of Population Growth~Successful family planning programmes~Availability of birth control methods~Higher levels of education among women~Economic development~Late marriages~Preference for small family size~Choice to remain single~High cost of livingConsequences of A Low Rate of Population Growth~lack of time to take care children~High cost of livingUnit 4 Rural and Urban SettlementsSettlements are formed when people come to live together.Rural Settlements~Villages ,Outside towns and cities ,countryside~consist of simple houses that are widely spread over an areaDominant Functions~carry out mainly primary activities~Farming (include growing crops and rearing livestock or poultry)~Fishing , Mining ,LumberingAmenitiesAmenities refers to the facilities and services provided to people in an area.In some LDCs still get water from rivers or wells.There is poor accessibility. Way of life~Simple way of life~pace of life is slower than in cities~less traffic and less pollution~children can play in open area~family unit tends to be closely knit and community activities throughout the year draw people togetherUrban Settlements~towns and cities~buildings built close to one another and occupy every inch of land~density of buildings is high~a dense network of roads laid in an orderly grid iron patternDominant Functionresidential ,administrative ,commercial ,industrialAmenities~Well-designed road systems (trains, MRT, LRT)~Wide range of good quality social services (community centres, town halls,schools and hospitals) are providedWay of life~Very fast pace of life~Homes are well furnished with basic necessities~More amenities (restaurants and recreational centres )~Play computer games or watch movie at home or in cinemas~Usually go shopping in large malls or supermarketsUnit 5 Settlement PatternsDispersed Settlements~Refers to the scattering of houses over a large area~In rural areas~Develop in hilly areas, on extensive flatlands or rolling plains~Amount of space between each house depends on the amount od land required to grow enough food for the family living thereLinear Settlements~refers to the grouping of houses along a line~tend to follow roads, railway tracks, along the coast or river banks~development of the linear settlement pattern is good transport and communication network~can be found in rural or urban areas, depending on their functions Nucleated Settlements~refers to the grouping of many houses together around a centre called nucleus ~usually of considerable size~vary from small villages to small towns and large towns and cities~develop on favourable sites at road intersections , focal points of an area or confluences of rivers~the community may grow in size to form a market town in the rural area~towns and cities may develop into urban centres and increase in the number of functionsUnit 8Transport and Communication Improvement in speedImprovement in passenger transportImproving Accessibility with transport network Improving Accessibility With Transport Infrastructure One-way CommunicationInteractive CommunicationCommunications And EducationCommunications And Cultural ChangeUnit 9 Singapore As a Transport and Communications HubLand Transport~efficient movements of people and goods~Economic development of a nation or region~Highway network~RailwaySea Transport~Handling import and re-export of cargoes~Situated at the crossroads of major international shipping routed~Harbour is also well-protected from strong windsAir Transport~Development of civil aviation~Changi Airport is one of the world’s busiest airport (direct flights/ key stopover/ increasing passenger)Roles of the Government and Entrepreneurs in making Singapore a Transport Hub ~maintain, promote~Attract new businesses to Singapore with greater accessibility and connectivity to the world~International Enterprise (IE) provides support for local entrepreneurs to kick start their business venturesFibre Optic Cable Network and Information Technology~Singapore has a network of underground fibre optic cables which greatly improves the efficiency , capacity and speed of communicationSatellite Technology~Improves long distance communication~Installed in telephone companies and cable television~Used in mobile phone and mobiles computing~The role of the Government in promoting satellites technology.Unit 10 Manging the Changing EnvironmentThe Impact Of Human Activities On The EnvironmentThe three varying impacts of human activities on the environment~Local scale~Regional scale~Global scale~Definition of local, regional and global scale~How we can protect and conserve the environment~How humans can manage the changing environment~If only relatively small areas are affected by human activities, then the impact or amount the environment changes because of human activities is at a local scale ~As long as human activities affect just a small area, we can say that the impact of change in the environment is at a local scale~Local scale = AFFECTS SMALL AREAS (just the area where the human activity occurs)Affecting the Environment at the LOCAL ScalePOSITIVE IMPACTS~Building dams and hydroelectric power stations~Clearing forests to increase arable land for farming~Building transport structures for easy accessibility~Building settlements to provide housing and work~Industries following regulations to reduce emission of harmful substances NEGATIVE IMPACTS~Deforestation destroying plant species and animal habitats~Air pollution from vehicles’exhaust fumes~Air pollution from factories~Sewage dumping polluting the water~Oil slick affecting marine life~Water pollution from industrial waste~Water pollution from pesticides and farm wasteAffecting the Environment at the REGIONAL Scale~When the impact caused by human activities covers a LARGE AREA, such as a CONTINENT or OCEAN, we say the impact is at the regional scale~Regional scale = COVERS LARGE AREA~Usually affects several cities or countries. In extreme cases can affect the entire continentAffecting the Environment at the REGIONAL ScaleNEGATIVE ACTIVITES AT A REGIONAL SCALE (affects several countries or a very wide distance)~Oil spills~Air pollution caused by forest fires~Air pollution that results in acid rainAffecting the Environment at the GLOBAL Scale~When the impact of pollution caused by human activities affects the WHOLE WIDE WORLD, we say that it is at a global scale~E.g.Global warming-Rise in global average temperature caused by an increase in air pollutants that keep excess heat in Earth’s atmosphere.Ozone depletion-Destruction of ozone layer which protects the Earth from harmful UV rays of the sunProtecting and Conserving the Environment~We now realise the extent of damage some of our human activities cause to the environment~As humans are smart and rational beings, we understand the importance of protecting and conserving environment~If we can conserve the environment, we can ensure our own survival as well as the next generation’s survivalINDIVIDUAL ACTIONS~Reduce, reuse, recycle~Anybody can perform the 3RsNATIONAL ACTIONS~A country can take direct and indirect actions to help protect and conserve the environment~Direct actions~Environmental protection policies e.g. fine people who cause forest fires within the country~Indirect actions~Education, campaigns, posters, pamphlets, TV shows to raise awareness of conserving the environmentREGIONAL ACTIONS~When a country cooperates with another country in the region to conserve the environment~E.g.-ASEAN countries work together to solve the problem of haze in SEA by signing an agreement in 2002INTERNATIONAL ACTIONSCooperation among nations (or many countries) can be achieved through~Attending Conventions (to learn about impact of human activities on the environment)~Signing Agreements-Montreal Protocol (1987) –to prevent Ozone Depletion-Kyoto Protocol (1987) –to minimise Global WarmingHow can we manage the changing environment?LAND SUPPLY~Manage the land when the demand for it increases~Control land use by proper pricing~Increase land supply by clearance and reclamation~Maximise land use in urban and rural areas~Conserve land by establishing natural reservesWATER RESOURCES~Protect this scarce resource~Increase price of water for more efficient use of water~Increase water supply by enlarging the catchment areas~Develop new technologies for increasing water supply (e.g. desalination & water supply)POLLUTION~Understand the nature of different kinds of pollution~Examine the causes and extent of pollution (local, regional or global scale)~Know the measures taken to reduce pollution at international, regional, national and individual levelsGLOBAL WARMING AND OZONE DEPLETION~Understand the extent of global warming and ozone depletion~Examine the causes and consequences of the problems~Know the measures taken to reduce greenhouse gases and ban the use of chlorofluorocarbonsUnit 13 Understanding the Water SupplyWater As A Scarce Resource~Uneven Distribution of Precipitation~Climate Change~Deforestation~Poor Farming PracticesReasons For The Rising Demand For Water~Increase in Population~Increasing in Agricultural Activities~Increase in industrial and commercial Activities Unit 14 Responses to the Rising Demand For water Increasing the price of waterIncreasing the water supply~Managing Catchment Areas~International Agreements~Desalination~Water ReclamationWater ConservationUnit15 Water Supply in SingaporeWater From local catchment areasImported water from JohorNEWater (reclaimed water)Desalinated WaterUnit 16 Understanding PollutionAir pollution~When the air is contaminated with dust , ash or harmful gases , it is polluted ~Factories and industries~Electric power generation~Incineration~Forest fires causing haze~Motor transport~Nuclear radioactivities~Volcanic eruptions~Wind actionLand pollution~When garbage( domestic or industrial waste )is disposed of indiscriminately in open dumps, drains and along roadsides, it causes land pollution~Seepage from landfills~Discharging industrial waste~Dumping garbage and raw sewage~Spilling oil in the seas~Littering and throwing rubbish on land~Poor farming practicesWater pollution~When our water supply in lakes rivers and seas is unfavourable for human use and harmful to aquatic life~Farming practices~Seepage from landfills~Discharging industrial waste~Dumping garbage and raw sewage~Spilling oil in the seasNoise pollution~When we are uncomfortable with the loud noises emitted by aircrafts , cars and trains , it is noise pollution~Motor vehicles (major source)~Heavy machinery (drilling/construction)~Office equipment (photocopiers)~Factory machinery~Electronic appliances~Power tools (drills)~Audio entertainment systems (loud speakers)~Affect the heart and increase blood pressure levelsExtent of Pollution~LOCAL SCALE (affects a small area/population)~REGIONAL SCALE (affects a large area/population)-Large area (several cities/countries/islands)-Long distance of damage (oil spills and thick haze can cover more than 700km) ~GLOBAL SCALE (affects whole world)-All countries in the world are facing the effects-Greenhouse gases (air pollution) ---global warming-Release of chlorofluorocarbons ---ozone depletionUnit 17 Coping with PollutionMeasures to Reduce Pollution International Level~Signing agreements, treaties or protocols~Get countries around the world to visit environmental conventions so that they can sign environmental agreements~We need to sign agreements to solve air pollution, marine pollution and solid waste pollution~E.g. Kyoto Protocol, Montreal ProtocolUnit 19 Heating up the EarthThe atmosphereThe lowest part of the atmosphere:~Presence of oxygen~Presence of ‘greenhouse gases’that trap heat from the sun~Keeps the Earth and the people warmGreenhouse Effect~Carbon dioxide and other gases trap the heat from the sun~This warming is known as ‘Greenhouse effect’Enhanced Greenhouse Effect~Air pollutants trap excess heat within the Earth’s atmosphere~This results in an excessive (too much) amount of greenhouse gases~Earth becomes warmer~Greenhouse gases include:1.carbon dioxide2.methane,3.nitrous oxide4.chlorofluorocarbonsCarbon Dioxide (CO2) Industrialization~Released when burning takes place~Fossil fuel (oil, coal) --- to generate more energy~Deforestation --- to create more land and spaceMethane (CH4) Agriculture~Natural by-product of bacterial action in the stomach of livestock (animals raised as sources of food) and water of rice fields~World’s population growing ---demand for food increasing --- more livestock and rice is grownNitrous Oxide (N2O) Industrialization & Agriculture~Burning of fuels~Chemical fertilizers containing nitrogenChlorofluorocarbons (CFCs)~Man-made chemicals for manufacturing aerosols, air-conditioners and refrigeratorsConsequences of Global Warming~Changes in world climate~Rise in sea levelChanges in world climate~Longer and drier summers, shorter and wetter winters in temperate regions~Higher rate of evaporation, increase in rainfall in tropical regions~Drier forest --- forest fireEffects of sea level change~Islands will be submerged (flooded)~Animals face extinction~Water supply becomes saline (salty)~River deltas will be floodedMeasures to reduce the impact of Global WarmingINDIVIDUAL~Reduce or limit the use of air-conditioners to reduce amount of chlorofluorocarbons released into the atmosphere~Avoid wasting electricity to reduce carbon dioxide emissions in the atmosphere NATIONAL~Environmental laws to reduce emission of greenhouse gases within the country INTERNATIONAL~Signing agreements, protocols, treaties so that all countries can collectively reduce emission of greenhouse gasesUnit 20 Depleting the Ozone LayerOzone Layer~Naturally occurring shield of ozone (O3)~Prevents ultraviolet rays from reaching the EarthHow is Ozone measured?~Dobson Units (D.U.)~Normal (healthy) ozone concentration: 500 Dobson Units and aboveExtent of Ozone depletionOzone Hole Over The Antarctica~South pole~The hole has become larger and deeper over the years~Especially during winter and spring~More ozone being destroyed~In summer, the hole repairs itselfOzone Hole Over The Arctic~Occurring at a smaller extent compared to Antarctica~Increasing rate in recent years~A great concern as more people are living in the Northern hemisphere Cause of Ozone Depletion (Ozone Depletor)~Chlorofluorocarbons (CFCs)~An organic compound that contains carbon, chlorine, and fluorine~Chlorine contained in the CFCs are destroying the ozone molecules in the ozone layerImpact on Animals~Increase in UV rays will reduce the population size of marine organisms such as plankton~Food chain disrupted or affectedImpact on Plants~Slow growth~smaller sizes due to exposure to UV radiationImpact on Humans~Skin disease such as cancer~Eye cataracts~Reduced immune systemDamages to materials~Plastic materials used outdoors will get damaged faster~E.g. PVC sidings, window and door frames, pipes and gutters used in buildings Global Climate~Increase the UV rays increase rate of global warming~Decrease in plankton will cause the amount of carbon dioxide (CO2) to increase in the atmosphereAT INDIVIDUAL LEVEL…~Buy products that are labelled “ozone-friendly”or “CFC-free”~Use fire extinguisher that do not contain ozone-depleting substances~Encourage everyone to spread the messageAT NATIONAL LEVEL…~Impose bans~E.g. Singapore banned the import and manufacture of aerosols and polystyrene products containing CFC in 1991)~Educate the citizensAT INTERNATIONAL LEVEL…~Signing of agreement to REDUCE or BAN CFCs emission~E.g. Montreal Protocol。
