Geography AS Revision
Geography AS RevisionHuman: Population ChangeKey WordsKey WordsFamine; a time when there is so little food that many people starve.Starvation; a state of extreme hunger resulting from lack of essential nutrients over a prolonged period.Green Belt; an area defined by Act of Parliament which surrounds a conurbation. It is very difficult to obtain permission for development on a green belt. This acts to stop the sprawl of conurbations.Studentificiation; large family houses too expensive to run are sold and sub divided and let to students. Nature of area starts to change (more noise, gardens untended, cars parked on road etc.) Pressures remaining residents to move out. Area deteriorates.Gentrification; families buy up run down property and improve it, adding to its value. As more people do this it attracts a richer population. The whole area may improve.Conurbation; one large, more of less continuous area created as a city grows and spreads to absorb other cities, towns and villages in the surround area.Infilling; the use of open spaces within a conurbation to build new housing or services, often close to where a green belt restricts outward growth.Brownfield Sites; sites that have been built on before but that have become available for new building because of demolition or redundancy of the old buildings.Social Welfare; the well being of communities. It refers to the access that groups of people or individuals have to job opportunities, education, an unpolluted environment, a safe environment and freedom to practise ones culture, religion etc.
Population IndicatorsBirth rateDeath rateFertility rateInfant mortality rateLife expectancyNet migration rateDifferences between the number of immigrants and emigrantsPopulation densityNumber of people per unit areaNatural increasePopulation Change the DTMDTM Describes how the population of a country changes over time. It gives changes in birth and death rates and shows that countries pass through five stages of population changeAdvantages;Universal in concept, therefore can be applied to all countriesTimescales are flexibleEasy to understandEnables comparisons to be made demographically between countriesProves helpful to governmentDisadvantages;Eurocentric, assumes that all countries will follow the same progress in terms of socio economic changeDoesnt include the role of governmentsDoesnt include the impact of migrationAssumes stage 2 follows industrialisation, but has been seen in many countries to be as a result of imported medical care, better sanitation etc.Doesnt account for countries that have slipped back into past stages due to diseaseDoesnt have a timescale!Doesnt include the impact of wars, or natural disastersPopulation Structures at Stage 1 of DMTPeriod of high birth and death rateHigh birth rate;Limited birth controlHigh infant mortality rateChildren are future source of incomeIn many cultures children are a sign of fertilitySome religions encourage large familiesHigh death rate;High incidence of diseasePoor nutrition and faminePoor levels of hygieneUnderdeveloped and inadequate health facilitiesPopulation Structures at Stage 2 of DMTPeriod of high birth rate and falling death rateFalling death rate;Improved public healthBetter nutritionLower child mortalityImproved medical provisionPopulation Structures at Stage 3 of DMTPeriod of falling birth rate and continuing fall in death rateFalling birth rate;Changing socioeconomic conditions, eg greater access to education for womenPreferences for smaller familiesChanging social trends and fashions, and a rise in materialismIncreased personal wealthCompulsory schooling, making the rearing of children more expensiveAvailability of family planning, often government supportedPopulation Structures at Stage 4 of DMTPeriod of fluctuating low birth and death rates
Population Structures at Stage 5 of DMTDeath rates exceeds birth rate slightly, decline in natural population (Natural decrease)Very low birth rate;Rise in individualism, linked to emancipation of women in the labour marketGreater financial independence of womenConcern about the impact of increased population on resourcesIncrease in non traditional lifestylesRise in the concept of childlessnessPopulation Structures Population PyramidsA population pyramid or age-sex structure is a composition of a population according to age groups and gender. The vertical axis of a population pyramid has the population in age bands of 5 yearsThe horizontal axis shows the number or percentage of males and females. The pyramid shows longevity by its height.
Population Structures- What Can Population Pyramids Show?The natural increase in specific groupsThe effects of migrationThe effects of events like wars, family or diseaseAn indication of the overall life expectancy of a countryWe can calculate the population dependency ratioHow Migration Affects the Population Structure of the Origin and DestinationOrigin;Younger age groups migrate leaving behind an ageing populationMales are more likely to migrate causing a contraction on that side of the pyramidBirth rates fall and death rates riseDestination;Proportions of younger adults increaseMales are more likely to migrate causing an expansion on that side of the pyramidBirth rates rise and death rates fallPopulation Pyramids at Different Stages of the DTMStage 1Wide base and concave shape. Low life expectancy and high death rates so there is a thin area on the top of the pyramidStage 2Wide base and a triangular shape. Higher life expectancy due to lower death rate, therefore is wider at the topStage 3Thinner base than in stage 1 or 2 and convex shape. Higher life expectancy and higher numbers of elderly peopleStage 4Thinner base than in stage 3 and convex shape. Much lower death rate and a higher life expectancyStage 5Thinner base than in stage 4 and convex shape, but curving inwards at the bottom. Small natural decreaseMalthusPessimisticPopulation grows at a geometric rate whilst food supply grows at an arithmetic rate.He said this would inevitably lead to famine (Natural checks) unless we limit population growth
Although population grew rapidly, food supply also grew more rapidly due toAgricultural revolution, increased efficiency due to machines, selective breeding.Trade of new agricultural lands, development of British EmpireEmigration and subsequent importation of foodBoserupOptimisticIncreases in population stimulate change in agriculture and therefore we will never run out of food supplies
Model a little too optimistic Over farming can lead to the degradation of farmland soilsMight come to a point where no more improvements can be madeDegradation of animal habitats and biodiversity => Affect food webs => Effect humansBased on idea of closed societyMany people, foreseeing a food shortage in their country, would migrate elsewhere.SimonOptimisticArgued supply of resources is infiniteAs a resource runs out, the price increases, so people invest time and thought into in producing technology that will;Find more of itExtract more what is already availableDiscover alternative resourcesChange the way society is organised to do without that resource
Model focussed more on the economic rather than scientific stand point
The Club of RomePessimistic/optimistic Computer simulation based on future development of the worlds population.If the present growth trends in world population, industrialisation, pollution, food production and resource depletion continue unchanged, the limits to growth on this planet will be reach in one hundred yearsIt is possible to alter these trends and establish a condition of ecological and economic stability that is sustainable far into the futureSustainable DevelopmentPrinciples of sustainability agreed in summits like Rio in 1992 and Kyoto 1997:EnvironmentalPeople at heart of concerns regarding developmentStates have the right to exploit there own environments but not damage those in other statesLaws enacted for liability regarding pollution and compensationStates should pass information about natural disasters and notify neighbours of the foreseen and accidental consequences of any activities that may cross frontiersEconomicThe right of development must be fulfilled to meet the needs of present and future generationsStates should work cooperatively to eliminate povertySpecial needs of LEDCs should be given priorityUnsustainable production and consumption should be eliminatedAppropriate demographic policies should be promoted
Natural Population Change and Migration Affect the Character of Rural and Urban AreasEffects of Migration EconomicCosts:
Source AreaDestination AreaLoss of young adult labour forceLoss of those with skills and entrepreneurial talentsCost of educating MigrantsOverdependence in some industries in migrant labourMuch of the money earned is repatriatedIncreased number of people pressures resourcesNatural Population Change and Migration Affect the Character of Rural and Urban AreasEffects of Migration EconomicBenefits
Source AreaDestination AreaReduced underemploymentReturning migrants bring new skillsMany migrants send remittances homeThere is less pressure on resourcesTake up less desirable jobsGains skilled labour at reduced costSkills gap is qualified by skilled migrantsCost of retirement are transferred to the area of originNatural Population Change and Migration Affect the Character of Rural and Urban AreasEffects of Migration SocialCosts
Source AreaDestination AreaMore people encouraged to migrate, detrimental effect on population structureDisproportionate number of females left behindNon returning migrants cause an imbalance in population pyramidReturning retired migrants may impose a social cost in the communityDominance of males is reinforcedAspects of cultural identity are lostSegregated area of similar ethnic groups are created and schools are dominated