Cambridge International AS and A Level Geography Revision Flashcards

NATURAL INCREASE AS A COMPONENT OF POPULATION CHANGE\n\n* Population Growth History: \n * The first hominids appeared in Africa approximately $5 \text{ million years ago}$.\n * Early humankind population remained very low: $10,000 \text{ years ago}$ it was no more than $5 \text{ million}$.\n * By $3500 \text{ BC}$, it reached $30 \text{ million}$, and by the time of Christ, about $250 \text{ million}$.\n * World population reached $500 \text{ million}$ around $1650$. From this point, growth occurred at an increasing rate.\n * By $1800$, the population reached $1 \text{ billion}$.\n\n* World Population Growth Milestones (Table 4.1):\n * 1st Billion: $1800$ (All of human history).\n * 2nd Billion: $1930$ ($130 \text{ years}$).\n * 3rd Billion: $1960$ ($30 \text{ years}$).\n * 4th Billion: $1974$ ($14 \text{ years}$).\n * 5th Billion: $1987$ ($13 \text{ years}$).\n * 6th Billion: $1999$ ($12 \text{ years}$).\n * 7th Billion: $2011$ ($12 \text{ years}$).\n * 8th Billion: $2024 \text{ (Expected)}$ ($13 \text{ years}$).\n\n* Recent Demographic Change: \n * Developing vs. Developed World: Growth is significantly higher in the developing world. The developing world\'s growth rate only overtook the developed world\'s after World War II. Developed nations experienced high growth in the 19th and early 20th centuries; developing nations experienced it after $1950$.\n * Global Peaks: The highest global growth rate was reached in the early-to-mid $1960\text{s}$ at $2.4\% \text{ per year}$ in the developing world. Since then, the rate has fallen, but population momentum meant additions peaked in the late $1980\text{s}$.\n\n* Components of Population Change: \n * Equation: Total change is the result of Natural Change (Births - Deaths) and Net Migration (Immigration - Emigration).\n * Methods of Statement: Natural change can be an absolute value (e.g., $200,000$) or a relative rate per thousand (e.g., $2/1000$).\n\n# FACTORS AFFECTING FERTILITY\n\n* Definitions: \n * Crude Birth Rate (CBR): The number of live births per $1000$ population in a given year. \"Crude\" indicates it applies to the total population without accounting for gender or age structure.\n * Fertility Rate: The number of live births per $1000 \text{ women}$ aged $15\text{--}49 \text{ years}$ in a given year. Much more accurate than CBR.\n * Total Fertility Rate (TFR): The average number of children born alive to a woman during her lifetime if she conformed to age-specific fertility rates of a given year.\n * Replacement-level Fertility: The level at which each generation replaces itself. A TFR of $2.1$ is usually considered replacement level.\n\n* Global Variations (2010 Data): \n * CBR: High of $52/1000$ (Niger); Low of $7/1000$ (Monaco).\n * TFR: High of $7.4$ (Niger); Low of $1.0$ (China, Macao and China, Hong Kong). Global average is $2.5$.\n\n* Main Categories of Factors (Table 4.2): \n * Demographic: Influence of infant mortality rates on fertility decisions.\n * Social/Cultural: Traditions demanding high reproduction in societies (e.g., Africa). Female literacy is the key to lower fertility. Religion is also an important influence.\n * Economic: In poor countries, children are economic assets. In developed countries, child-dependency costs discourage large families.\n * Political: Government attempts to change growth for economic or strategic reasons.\n\n# FACTORS AFFECTING MORTALITY\n\n* Definitions: \n * Crude Death Rate (CDR): Number of deaths per $1000$ population per year. Influenced by age structure (e.g., UK at $9/1000$ due to older population vs. Brazil at $6/1000$).\n * Infant Mortality Rate (IMR): Number of deaths of infants under $1 \text{ year}$ per $1000 \text{ live births}$ per year. Often seen as the most sensitive indicator of socio-economic progress.\n * Life Expectancy (at birth): Average number of years a person is expected to live assuming past trends continue.\n\n* Global Mortality Comparisons (2010): \n * CDR Range: High of $20/1000$ (Zambia); Low of $1/1000$ (Qatar).\n * IMR Range: Africa ($76/1000$) vs. Europe/North America ($6/1000$).\n * Life Expectancy: Africa ($55 \text{ years}$) vs. North America ($78 \text{ years}$).\n\n* Causes of Death: \n * Developing World: Over $40\%$ from infectious and parasitic diseases (e.g., TB, cholera, malaria, measles). Factors include overcrowding, poor sanitation, limited healthcare, and poor nutrition.\n * Rich Countries: Primary killers are heart disease and cancer.\n\n# POPULATION STRUCTURE AND THE DEPENDENCY RATIO\n\n* Population Structure: The composition of a population, usually aged by age and sex, represented by a population pyramid.\n* Pyramid Interpretation: \n * Wide Base: High fertility/birth rate.\n * Narrow Base: Low fertility.\n * Broad Top: High proportion of elderly/long life expectancy.\n * Side Bulges: Baby boom or period of immigration for economically active years.\n * Indents: High death rates from war, famine, disease, or emigration.\n\n* Dependency Ratio: Relationship between the economically active population ($15\text{--}64$) and non-working dependents ($0\text{--}14$ and $65+$).\n * Formula: $\text{Dependency Ratio} = \frac{\text{number aged 0-14} + \text{number aged over 64}}{\text{number aged 15-64}} \times 100$\n * Elderly Dependency Ratio: $\frac{\text{number aged over 64}}{\text{number aged 15-64}} \times 100$\n * Youth Dependency Ratio: $\frac{\text{number aged 0-14}}{\text{number aged 15-64}} \times 100$\n * Significance: A ratio of $60$ means $60 \text{ dependents}$ per $100 \text{ workers}$. Developed countries usually range between $50\text{ and }75$ (mostly elderly). Developing countries can reach over $100$ (mostly young).\n\n# THE DEMOGRAPHIC TRANSITION MODEL (DTM)\n\n* Stage 1 (High Stationary): High stable birth rates and high fluctuating death rates (war, famine, disease). Slow growth, high IMR, low life expectancy.\n* Stage 2 (Early Expanding): Death rate falls significantly (better nutrition, public health, water, medical advances). Birth rate remains high (social norms take time to change). Peak natural increase occurs at the end of this stage.\n* Stage 3 (Late Expanding): Birth rate begins to decline as norms adjust. Life expectancy continues to increase, IMR decreases.\n* Stage 4 (Low Stationary): Low birth and death rates. Slow growth. Death rates rise slightly due to population ageing, but age-specific mortality still falls.\n* Stage 5 (Natural Decrease): Birth rate falls below death rate. Population declines without net immigration.\n\n* Criticisms of DTM: \n * Too Eurocentric (based on Western Europe).\n * Developing countries may not follow the sequence.\n * Fails to account for migration effects.\n\n# POPULATION-RESOURCE RELATIONSHIPS\n\n* Carrying Capacity: The largest population that environment resources can support. It is dynamic, as technology can increase it.\n* Ecological Footprint: A sustainability indicator measuring human demand on the environment. It includes: built-up land, fishing ground, forest, grazing land, cropland, and carbon footprint.\n * Global Hectare: Equivalent to one hectare of biologically productive space with global average productivity.\n * Overshoot: Humankind\'s footprint reached biocapacity in the mid-$1980\text{s}$. Recent data shows the footprint exceeds regenerative capacity by about $30\%$.\n\n* Theories of Growth: \n * Thomas Malthus (1798): Population grows in geometrical progression ($1-2-4-8-16-32...$) while food supply grows in arithmetical progression ($1-2-3-4-5-6...$). Result: famine, disease, or war balance the two.\n * Resource Optimists (e.g., Boserup): Human ingenuity and innovation allow intensification and technology to respond to population pressure. Examples include the Green Revolution.\n\n* The Green Revolution: Introduction of high-yielding variety (HYV) seeds (wheat, rice, maize, sorghum, millet) and modern techniques. \n * Advantages: Yields $2 \text{ to } 4 \times$ greater, shorter growing seasons, increased rural incomes.\n * Disadvantages: High fertilizer/pesticide costs, increased salinisation, rural unemployment through mechanisation, benefit primarily to wealthy farmers.\n\n# CASE STUDY: MANAGING NATURAL INCREASE IN CHINA\n\n* The One-Child Policy (Introduced 1979): \n * Mechanism: Reward and penalty approach. Rural households obeying rules receive priority loans and welfare. Slogan: \"shao sheng kuai fu\" (fewer births, quickly richer).\n * Results: Prevented at least $300 \text{ million births}$. CBR fell from $43.8/1000$ ($1950$) to $13.6/1000$ ($2005$).\n * Adverse Consequences: demographic ageing, unbalanced sex ratio ($119 \text{ boys to } 100 \text{ girls}$), \" spoiled generation,\" and the \"four-two-one\" problem (one child supporting two parents and four grandparents).\n\n# MIGRATION FUNDAMENTALS\n\n* Definitions: \n * Migration: Movement of people across a boundary to establish a new permanent residence (defined by UN as lasting over $1 \text{ year}$).\n * Net Migration: $Immigration - Emigration$.\n * Push Factors: Negative factors at origin (poor jobs, disasters). \n * Pull Factors: Positive factors at destination (high wages, amenities).\n * Voluntary vs. Forced: Voluntary is free choice; Forced has little to no choice (e.g., slavery, natural disasters).\n * Impelled Migration: Takes place under threat but with an element of choice remaining.\n\n* Recent Models/Theories: \n * Todaro Model: Cost-benefit approach; migrants move based on realistic long-term expectations of socio-economic gain, even if short-term is worse.\n * Stark\'s New Economics: Focuses on the household as the unit of analysis; migration is household risk-spreading/diversification.\n * Structuration Theory: Incorporates individual motives and rules/structures of operation.\n\n# CASE STUDY: BRAZIL RURAL-URBAN MIGRATION\n\n* Push Factors: Agricultural mechanization, farm amalgamation, poor rural conditions, desertification (Northeast), deforestation (North).\n* Pull Factors: Likelihood of informal employment, proximity to health/education, retail access, social attractions of cities (São Paulo, Rio de Janeiro).\n\n# INTERNATIONAL MIGRATION IMPACTS\n\n* Remittances: World Bank reported $397 \text{ billion}$ in $2008$, with $305 \text{ billion}$ going to LEDCs. Surpasses official aid. India, China, Mexico, and Philippines are top destinations.\n* Culture and Diaspora: Dispersal from original homeland. Creates cultural hybridity and bilingualism (e.g., Spanish in USA).\n* Refugees vs. Internally Displaced Persons (IDP): Refugees cross international borders due to fear of persecution; IDPs stay within the same country.\n\n# URBAN AND RURAL SETTLEMENT DYNAMICS\n\n* Cycle of Urbanisation: \n * Suburbanisation: Outward growth into surrounding villages.\n * Counterurbanisation: Movement from large urban areas to smaller settlements/rural areas.\n * Reurbanisation: Population increase in city centers after a period of decline (e.g., London since the mid-$1980\text{s}$).\n\n* Urban Land Models: \n * Burgess Concentric Zone: CBD in center, surrounded by transition zone, working-class homes, residential, and commuters zone.\n * Hoyt Sector: Wedge-shaped sectors following transport routes.\n * Harris and Ullman Multiple Nuclei: Develops around multiple discrete centers (e.g., old villages or industrial estates).\n * Bid-Rent Theory (Alonso): Distance from center determines land use based on rent affordability; shops/offices bid highest for most central access.\n\n* Global (World) Cities: Important nodes in global economics (Alpha ++: London, New York). Powered by demographic trends, economic development, and cultural status.\n\n* Urban Management Issues: \n * São Paulo: $20\%$ of population in favelas ($2 \text{ million people}$). Heliopolis is the largest slum. \"Projecto Cingapura\" tried to provide high-density housing but abandoned after only $14,000 \text{ units}$.\n * Cairo: Population density of $30,000/\text{km}^2$. Infrastructure designed for $2 \text{ million}$ serves far more. metro system handles $2 \text{ million rides/day}$. \"10 \text{ new cities}\" on periphery aimed to decentralize.\n * China Hukou System: Population register restricting rural-urban movement. Permission needed to leave countryside. Emphasis on \"in situ urbanisation\" where rural settlements transform without population movement (e.g., Quanzhou)."