भूगोल Geography

Quick summary

This chapter studies how people are spread over the earth (distribution), how crowded places are (density), what physical and human factors affect them, and how population grows. It ends with the Demographic Transition Theory, which explains how birth and death rates change as a country develops.

Key points

• Population distribution is the way people are spread over the earth's surface. It is very uneven: some areas are crowded, others almost empty.
• Population density = number of people living per square kilometre.
• Physical factors: relief (flat plains attract people; mountains discourage), climate (moderate climate preferred; very hot, cold or dry regions have few people), water, soil, minerals and forests.
• Human factors: jobs and means of livelihood, industries, cities with education and health facilities, transport, political and social factors.
• High density areas: East and South Asia, Western Europe, north-east USA. Low density: deserts (Sahara), polar areas, Amazon forests, high mountains.
• Population growth / change = change in the number of people in an area over a period. It depends on births, deaths and migration.
• Crude Birth Rate (CBR) = live births in a year per 1000 people. Crude Death Rate (CDR) = deaths in a year per 1000 people.
• Natural growth = CBR – CDR. Very fast growth is called a population explosion.
• High stationary – high birth and death rates; growth stable; undeveloped economy.
• Early expanding – death rate falls fast (medicine, food) but birth rate stays high; highest growth (population explosion).
• Late expanding – both rates fall; growth slows; countries moving towards developed.
• Low stationary – both rates low; population stable.
• Declining – birth rate very low, may fall below death rate; population falls (e.g. some European countries, Japan).
• Demographic Transition Theory – 5 stages:
• India is moving through the later part of the expanding stages, with birth rates falling.

Important terms

• Population density – people per sq km.
• CBR / CDR – births / deaths per 1000 population per year.
• Natural increase – birth rate minus death rate.
• Population explosion – very rapid rise in population.
• Demographic transition – change from high birth and death rates to low ones as a country develops.

Key facts

5 important questions

Q1. Give geographical reasons: Mountainous regions have low population density.

Mountains have steep slopes, thin soils, cold climate and poor transport. Farming and industries are difficult, so there are few means of livelihood and fewer people live there.

Q2. Explain the human factors affecting population distribution.

Availability of jobs, industries and urban facilities like schools and hospitals attracts people. Good transport and communication, political stability and social factors also lead to concentration of population.

Q3. Define crude birth rate and crude death rate.

CBR is the number of live births in a year per 1000 population. CDR is the number of deaths in a year per 1000 population of a region.

Q4. Explain the second stage of the Demographic Transition Theory.

Due to better medicine, food and hygiene, the death rate falls quickly while the birth rate stays high. The gap between the two is the largest, so population grows fastest. This is the population explosion stage.

Q5. If CBR is 7 and CDR is 8, in which stage is the country?

The death rate is higher than the birth rate, so population is falling. The country is in Stage 5 – the declining stage.

Exam tip

Practise drawing the labelled demographic transition diagram with five stages — it is a frequent 4-mark question.

Quick summary

This chapter is about the composition (make-up) of population: age structure and population pyramids, sex ratio, demographic dividend, literacy, occupational structure and rural–urban population. It also explains migration — its types, causes (push and pull factors) and effects.

Key points

• Population composition = all measurable characteristics of a population: age, sex, literacy, occupation, residence etc.
• Age structure = number of people in different age groups: young (0–14), working (15–59/64) and old (60/65+).
• Population pyramid shows age and sex structure: males on the left, females on the right.
• Three types of pyramids: (1) Expansive – broad base, narrow top: high birth and death rates (developing countries like Afghanistan, Pakistan); (2) Constrictive – narrow base: low birth rate, more old people (Japan, some European countries); (3) Stationary/near-stationary – almost equal width: stable population.
• Sex ratio = number of females per 1000 males (in India). The world average is about 990. Very high in Latvia, Estonia, Russia, Ukraine (1162); very low in Saudi Arabia (667).
• Demographic dividend – faster economic growth when the share of working-age people is high. India is in this phase now.
• Literacy – each country defines it; in India a person aged 7+ who can read and write with understanding is literate.
• Occupational structure – share of workers in primary (farming, fishing, mining), secondary (manufacturing) and tertiary (services) sectors.
• Migration = movement of people from one place to another, for a short or long period or permanently.
• Types: internal / international; seasonal, short-term, long-term, permanent; rural–urban, urban–urban etc.
• Push factors (drive people away): unemployment, poverty, drought, floods, war, lack of facilities. Pull factors (attract people): jobs, higher wages, education, health care, safety.
• Effects: remittances to home area, new skills; but crowding, slums and pressure on services in cities; imbalance in sex ratio and loss of youth in source areas.

Important terms

• Population pyramid – bar graph of age–sex structure.
• Sex ratio – females per 1000 males.
• Dependency ratio – non-working (young + old) compared to working-age people.
• Demographic dividend – economic benefit from a large working-age population.
• Migration – movement of people across boundaries for some period.

Key facts

• World average sex ratio ≈ 990 females per 1000 males.
• Highest: 1162 (Latvia, Estonia, Russia, Ukraine); lowest: 667 (Saudi Arabia).
• Expansive pyramid = developing; constrictive = developed/ageing.

5 important questions

Q1. Distinguish between expansive and constrictive pyramids.

An expansive pyramid has a broad base and narrow top, showing high birth and death rates and a young population (developing countries). A constrictive pyramid has a narrow base and wider middle/top, showing low birth rates and an ageing population (developed countries).

Q2. What is demographic dividend?

It is the economic growth that comes from a change in age structure, when the working-age population is larger than the dependent population. More workers can raise production and savings.

Q3. Give geographical reasons: Sex ratio is low in some Gulf countries.

Many male workers migrate there for jobs in oil and construction industries, so males far outnumber females.

Q4. Explain push and pull factors of migration.

Push factors make people leave a place — unemployment, poverty, natural disasters, conflict. Pull factors attract people to a place — jobs, better wages, education, health facilities and security.

Q5. State the effects of migration on the destination area.

Labour becomes available and the economy grows, and cultures mix; but there is overcrowding, growth of slums, pressure on water, housing and transport, and sometimes social tension.

Exam tip

Draw a small sketch of each pyramid type when asked to "distinguish" — it earns full marks quickly.

Quick summary

A settlement is a group of houses built by people living together at a place. This chapter explains types and patterns of settlements, rural and urban settlements, functional classification of towns, and how land is used in rural and urban areas, including the CBD and the rural–urban fringe.

Key points

• Settlement (वस्ती) – a place where people build houses and live together for social and economic needs. They range from a hamlet to a metropolitan city.
• Types (by spacing of houses): (1) compact / clustered / nucleated, (2) semi-clustered / fragmented, (3) dispersed, (4) isolated.
• Type vs pattern: type is a category with common features; pattern is the regular shape or order in which settlements occur.
• Patterns: linear (along road, rail, river, canal), rectangular (parallel lines, planned towns), radial (around a central point), circular (around a lake), triangular (at a confluence of rivers or roads, or along a coast), patternless (haphazard growth).
• Rural vs urban: rural settlements depend mostly on primary activities; urban settlements on secondary and tertiary activities, with higher density and more services.
• Urban settlements in India are grouped by population into Class I to Class VI (Class I = 1 lakh and above).
• Functional classification of towns: administrative, industrial, transport, commercial, mining, cantonment, educational, religious, tourist. Big cities usually do many functions.
• Rural land use classes (9-fold): forests; land under non-agricultural uses; barren and wasteland; permanent pastures and grazing land; tree crops and groves; culturable wasteland (fallow over 5 years); current fallow (1 year or less); other fallow (1–5 years); net sown area.
• Urban land use: residential, industrial, institutional, commercial (shops, offices – the CBD), recreational, transport, plot layouts, mixed land use.
• CBD (Central Business District) – the commercial heart of a city with offices, banks and big shops.
• Rural–urban fringe – the zone between city and village where both land uses mix; unplanned outward growth is urban sprawl.

Important terms

• Settlement – a group of dwellings with people living together.
• Conurbation – a large urban area formed when cities grow and merge.
• Net sown area – actual area on which crops are sown and harvested.
• Culturable wasteland – land left uncultivated for more than five years.
• Urban sprawl – haphazard spread of a city into surrounding rural land.

Key facts

5 important questions

Q1. Distinguish between compact and dispersed settlements.

In compact settlements houses are built close together, usually in fertile plains with water supply and for security. In dispersed settlements houses are far apart, found in hilly, forested or dry areas where land is scattered.

Q2. Give geographical reasons: Linear settlements develop along rivers and roads.

Rivers provide water and roads give easy transport and trade. People build houses along them, so the settlement takes a long, straight shape.

Q3. Explain the functional classification of towns.

Towns are grouped by their main function: administrative (Delhi), industrial (Jamshedpur), transport (Bhusawal), commercial, mining, cantonment (Ahmednagar camp), educational, religious (Pandharpur) and tourist (Mahabaleshwar). Big cities often have many functions.

Q4. What is current fallow?

Cultivable land left without crops for one agricultural year or less, to let the soil regain fertility naturally.

Q5. What is the rural–urban fringe?

The area between a city and the countryside where urban and rural land uses mix. Farmland is converted to plots, houses and industries as the city expands.

Exam tip

In "distinguish" questions on settlements, compare location, spacing, size, and an example — four points in a table.

Quick summary

Primary economic activities use natural resources directly — hunting, gathering, lumbering, fishing, mining, animal husbandry and agriculture. This chapter explains these activities, where they are found in the world, the natural and man-made factors that affect them, and the main types of agriculture.

Key points

• Primary activities depend directly on nature (land, water, forests, minerals, climate). People doing them are sometimes called "red-collar workers".
• Factors: natural (land, soil, slope, climate, rainfall, water) and man-made (fertilisers, machines, irrigation, technology, markets, capital).
• Hunting – the oldest activity; commercial hunting is now banned. Some tribes still hunt for food (e.g. Bushmen of the Kalahari, Pygmies of equatorial forests, Inuit/Eskimos).
• Gathering – collecting forest products like fruits, honey, gum, medicinal plants, rubber. Mostly in tropical and equatorial forests.
• Lumbering – cutting trees for timber; well developed in temperate coniferous forests (Canada, Russia, Scandinavia) because trees are softwood, grow in pure stands and are easy to transport.
• Fishing – most developed where warm and cold ocean currents meet and on wide continental shelves: Grand Banks (NE coast of North America), Dogger Bank (North Sea), around Japan, Peru coast.
• Mining – extracting minerals; depends on the presence of mineral deposits, technology, capital and transport, not on latitude.
• Animal husbandry – rearing animals for milk, meat, wool; linked to grasslands — nomadic herding (dry areas) and commercial ranching (Prairies, Pampas, Downs, Velds).
• Types of agriculture: shifting (slash-and-burn, tropical forests); subsistence intensive (monsoon Asia, rice, manual labour – India, China, Japan, Sri Lanka); extensive commercial (large mechanised wheat farms in temperate grasslands – Prairies, Pampas, Downs, Velds); plantation (single cash crop like tea, coffee, rubber, sugarcane on large estates – Brazil, Indonesia, Caribbean, Sri Lanka); horticulture (fruits, flowers, medicinal plants); market gardening/truck farming (vegetables near cities); mixed farming (crops + animals).

Important terms

• Primary activity – an activity that takes resources directly from nature.
• Shifting agriculture – clearing forest by burning, farming for a few years, then moving on (called "jhum" in north-east India).
• Plantation agriculture – large-scale farming of one cash crop, often for export.
• Extensive farming – large farms, few workers, heavy machinery, low yield per hectare.
• Intensive farming – small farms, more labour and inputs, high yield per hectare.

Key facts

5 important questions

Q1. Give geographical reasons: Fishing is well developed on the north-east coast of North America.

The cold Labrador current and warm Gulf Stream meet there and the continental shelf (Grand Banks) is wide and shallow. This supports plenty of plankton, the food of fish, so fish are abundant.

Q2. Distinguish between intensive and extensive agriculture.

Intensive: small farms, many workers, high inputs, high yield per hectare, mainly food crops for the family (monsoon Asia). Extensive: very large farms, few workers, heavy machines, lower yield per hectare but large total output for sale (temperate grasslands).

Q3. Why is lumbering developed in temperate coniferous forests?

Trees are softwood and useful for paper and furniture; they grow in pure stands of one species; there is little undergrowth; and frozen ground and rivers help transport logs.

Q4. What are the characteristics of plantation agriculture?

Large estates, one cash crop, heavy capital investment, many labourers, scientific methods, processing on the estate, and production mainly for export.

Q5. Why is mining not related to latitude?

Minerals are found wherever geological conditions formed them. Mining depends on mineral deposits, technology, capital and transport, so it occurs at all latitudes.

Exam tip

For world-map questions, practise marking Grand Banks, Dogger Bank, Prairies, Pampas, Downs and Velds.

Quick summary

Secondary economic activities change raw materials into more useful and valuable goods — that is, manufacturing. This chapter covers the factors that decide where industries are located, the major industrial regions of the world, and how industries are classified, including MSMEs in India.

Key points

• Secondary activity adds value to raw materials by processing (e.g. sugarcane → sugar, iron ore → steel).
• Physical factors of location: climate (moderate climate preferred), raw material, water, power/energy, land.
• Economic factors: nearness to market (especially for heavy, perishable or bulky goods), labour, capital, transport and communication, banking and credit.
• Political factors: government policies — incentives, subsidised land, tax relief, special zones for backward areas (e.g. Maharashtra's "D and D+" category areas); restrictions in some areas for pollution or security.
• Other factors: split location (parts made in different places and assembled at one place, e.g. automobiles, mobiles), economies of scale and agglomeration (industries cluster where facilities already exist), industrial inertia.
• Sugar industry is raw-material oriented because cane loses sucrose soon after cutting — e.g. many sugar mills in Solapur district.
• Major industrial regions: North America (north-eastern USA, Great Lakes region, Pittsburgh, California); Europe (Ruhr in Germany, Midlands in UK, north France); European Russia (Moscow–Tula–Vladimir, Ural–Volga); East Asia (Japan, China, South Korea, Taiwan); India (Mumbai–Pune, Ahmedabad–Vadodara, Bengaluru–Chennai, Chota Nagpur, Hugli belt).
• Classification of industries: by capital (large, small, micro; cottage/household); by ownership (private, public, joint, co-operative); by source of raw material (agro, mineral, forest, marine, animal based); by output (basic/heavy and consumer goods); multinational companies.
• MSME (as given in the textbook): micro – plant and machinery investment up to ₹25 lakh; small – above ₹25 lakh up to ₹5 crore; medium – above ₹5 crore up to ₹10 crore (lower limits apply for service firms).

Important terms

• Agglomeration – concentration of many industries in one area to share facilities.
• Footloose industry – industry not tied to any raw material location (e.g. electronics).
• Split location – different stages of production at different places.
• Cottage industry – manual production at home using local materials and family labour.
• Co-operative sector – industry owned and run by its members (e.g. co-operative sugar factories in Maharashtra).

Key facts

5 important questions

Q1. Give geographical reasons: Sugar factories are located near sugarcane fields.

Sugarcane is bulky and loses its sugar content quickly after harvest. Transporting it far would raise cost and lower recovery, so mills are set up near cane-growing areas like Solapur, Kolhapur and Ahmednagar.

Q2. Explain economic factors affecting location of industries.

Nearness to markets reduces transport cost; cheap and skilled labour; availability of capital and banking; good transport and communication for moving raw material and finished goods.

Q3. How do government policies affect industrial location?

Governments give land, power, water and finance at concessional rates and tax relief in backward regions to encourage industry. They may also ban industries in ecologically sensitive or crowded areas.

Q4. What is agglomeration of industries?

When facilities like power, transport, banking and skilled labour are available, more industries come to that region over time. This clustering, which lowers costs for all, is called agglomeration (e.g. Pune–Chakan automobile belt).

Q5. Classify industries on the basis of ownership.

Private sector (owned by individuals/companies), public sector (owned by government), joint sector (government and private together), co-operative sector (owned by members).

Exam tip

Questions often ask "give reasons" for the location of a specific industry — always link it to one main factor (raw material, market, power or labour).

Quick summary

Tertiary activities do not produce goods directly; they provide services — trade, transport, communication, banking, tourism and other services. This chapter explains their classification and importance, and the newer quaternary and quinary activities.

Key points

• Tertiary activities offer services and help exchange; they link primary and secondary activities with consumers. Workers in offices and services are often called "white-collar workers".
• Classification: (1) trade and commerce, (2) transport, (3) communication, (4) other services (banking, insurance, real estate, personal and professional services, tourism).
• Trade: wholesale (bulk buying and selling – urban wholesale markets, rural mandis) and retail (sale to consumers – periodic markets/weekly bazaars, street peddling, shops, chain stores, malls, Public Distribution System).
• Geographical diversity causes trade: different regions produce different goods.
• Transport: road, rail, water, air and pipelines. Roads give door-to-door service; railways carry bulky goods over long distances; water transport is cheapest for heavy cargo; airways are fastest and growing; pipelines carry oil, gas and water.
• Important routes: Trans-Siberian railway (St Petersburg to Vladivostok), Trans-Australian railway (Perth–Sydney); Suez Canal joins the Mediterranean and Red Sea (Europe–Asia/Africa); Panama Canal joins the Atlantic and Pacific.
• Ports: natural ports like Mumbai and Kochi; JNPT; cargo terminals like Delhi International Cargo Terminal and MIHAAN (Multi-modal International Cargo Hub and Airport at Nagpur).
• Communication: post, telephone, mobile, radio, TV, internet, satellites and GPS; it helps trade, administration and disaster warning.
• Tourism – an important service industry that earns foreign exchange and creates jobs; depends on climate, scenery, history, culture and accessibility.
• Quaternary activities – knowledge-based services: research, information technology, education, consultancy, data processing.
• Quinary activities – the highest-level decision making: top executives, policy makers, government officials, senior scientists ("gold-collar" professionals).

Important terms

• Wholesale trade – buying in large quantity from producers and selling to retailers.
• Retail trade – selling goods in small quantities to consumers.
• Periodic market – market held on fixed days (weekly bazaar).
• Quaternary activity – service based on knowledge and information.
• Quinary activity – top-level decision making and policy work.

Key facts

5 important questions

Q1. Give geographical reasons: Tertiary activities include both services and exchange.

They do not produce goods but provide services like transport, banking and health, and also carry out exchange of goods through wholesale and retail trade between producers and consumers.

Q2. Distinguish between wholesale and retail trade.

Wholesale: bulk quantities, bought from producers, sold to retailers, few large markets. Retail: small quantities, sold directly to consumers through shops, malls, weekly markets and hawkers.

Q3. Why is the share of air transport increasing?

It is the fastest mode, reaches remote and hilly areas, is suitable for perishable and costly goods and passengers, and incomes and global business travel have grown.

Q4. What are quaternary and quinary activities?

Quaternary activities are knowledge-based services such as research, IT and education. Quinary activities are the highest decision-making functions done by top executives, government officials and policy makers.

Q5. Explain the importance of communication.

It spreads information quickly, supports trade and banking, helps governance and disaster warnings, brings people closer and makes services like online education and GPS navigation possible.

Exam tip

Remember the "collar" names: red (primary), blue (secondary), white (tertiary), gold (quinary) — handy for one-mark questions.

Quick summary

A region is an area that is different from other areas because of some common features. This chapter explains what a region is, its attributes, formal and functional regions, the meaning of regional development, its indicators, the causes of regional imbalance in India, and strategies to reduce it.

Key points

• Region (प्रदेश) – a geographical area with common, homogeneous characteristics that make it different from other areas. It is the basic unit of geographical study.
• Regions may be based on natural features (relief, climate, vegetation, soil) or man-made features (language, administration, economy). Example: Himalayas vs Northern Plains.
• Attributes of a region: location, spatial extent, boundary, hierarchical arrangement (sub-regions inside larger regions, e.g. Northern Plains → Ganga–Yamuna plains).
• The States Reorganisation Act, 1956 drew state boundaries on the basis of language (e.g. Maharashtra for Marathi speakers).
• Formal region: area with one or more common characteristics and clear boundaries — physical (river basin) or political (district, state). Examples: Europe, Assam.
• Functional region: area bound together by a function, often around a centre — e.g. Pune Metropolitan Region, the area served by a milk collection centre, a TV tower, a pizza outlet's delivery zone.
• Regional development – improvement of a region's economy and people's quality of life. Indicators: per capita income, percentage below poverty line, urbanisation, irrigated area, electricity use, literacy, life expectancy, Human Development Index (HDI), share of primary/secondary/tertiary sectors.
• As a region develops, workers shift from the primary sector to secondary and tertiary; birth and death rates fall (later stages of demographic transition).
• Regional imbalance in India: caused by physical factors (difficult terrain, lack of resources, poor accessibility) and economic factors (private investment goes to areas with infrastructure). The North-East and hilly states lag; Marathwada and Vidarbha lag within Maharashtra.
• Strategies: identify backward areas, give special funds and subsidies, build roads, power, water, schools and health centres, skill development, special programmes for drought-prone, desert, hilly and tribal areas, decentralisation of industries, good governance.

Important terms

• Region – a homogeneous area different from surrounding areas.
• Formal region – region with common characteristics and definite boundary.
• Functional region – region linked by a function or flow around a centre.
• Regional imbalance – unequal levels of development among regions.
• HDI – index combining health, education and income.

Key facts

5 important questions

Q1. What are the attributes of a region?

Every region has a location (latitude–longitude), a spatial extent, a boundary beyond which another region begins, and a hierarchy, i.e. it can contain sub-regions or be part of a larger region.

Q2. Distinguish between formal and functional regions.

A formal region shares common characteristics such as language, crop or climate and has fixed boundaries (e.g. a state). A functional region is bound by a function or service around a centre, and its boundary changes with that function (e.g. Pune Metropolitan Region).

Q3. State the indicators of regional development.

Per capita income, poverty level, urbanisation, irrigated area, electricity consumption, literacy, life expectancy, HDI, and the share of workers in secondary and tertiary sectors.

Q4. Why is there regional imbalance in India?

Difficult relief, lack of resources and poor accessibility in some regions; concentration of private investment where infrastructure already exists; and historical and social factors.

Q5. Suggest measures to reduce regional imbalance.

Special funds and subsidies for backward areas; all-weather roads, electricity and drinking water; schools, health care and skill training; decentralisation of industries; and good governance.

Exam tip

Short notes on "measures to reduce regional imbalance" are common — write 5–6 points from the strategy chart.

Quick summary

This chapter looks at geography itself as a subject: what it studies (nature), how it is linked with other subjects (scope), its branches, the latest trends and tools, and the career opportunities it offers.

Key points

• Geography studies the earth's physical environment and human activities and the relationship between them.
• Two main branches: Physical Geography (lithosphere – landforms, relief; atmosphere – weather, climate, winds; hydrosphere – oceans, rivers; biosphere – life, ecosystems) and Human Geography (relationship between people and environment; population, settlements, economy, culture).
• Study of space and time – where things are and how they change over time; it answers Where, When, What and Why.
• Cause and effect – explains why things are distributed as they are.
• Empirical and practical – based on observation, surveys, maps, satellite images, data and statistics.
• Dynamic – phenomena keep changing.
• Dualism – two contrasting approaches, e.g. environmental determinism (nature controls man) vs possibilism (man can modify nature); regional vs systematic study.
• Interdisciplinary / integrating subject.
• Nature of geography:
• Early geographers: Hecataeus (Greek) – "Ges Periodus", first systematic description of the world; Ptolemy – "Geography" with an atlas; Strabo (Roman) – "Geographica" in 17 volumes.
• Scope – links with other subjects: Geology → Geomorphology; Meteorology → Climatology; Hydrology → Oceanography; Pedology → Soil Geography; Economics → Economic Geography; Sociology → Social Geography; Political Science → Political Geography; Demography → Population Geography; History → Historical Geography; Mathematics/Statistics → Cartography and quantitative methods; Computer science → GIS.
• Latest trends: GIS (Geographic Information System), remote sensing, GPS, data science and machine learning, climate change studies, disaster management.
• Careers: cartographer, GIS analyst, urban planner, climatologist, disaster manager, data scientist, environmental consultant, teacher and researcher, tourism.

Important terms

• Environmental determinism – belief that the natural environment controls human life.
• Possibilism – belief that humans can choose and change their environment.
• Dualism – two opposite approaches existing in one subject.
• Cartography – the art and science of map-making.
• GIS – computer system to store, analyse and display geographical data.

Key facts

5 important questions

Q1. Why is geography called a study of space and time?

It studies where phenomena are located on the earth (space) and how they change over periods (time), e.g. climate is decided from about 30 years of weather, and population changes over decades.

Q2. What is dualism in geography?

The existence of two contrasting approaches in the subject, such as environmental determinism vs possibilism, or physical vs human geography, or regional vs systematic study.

Q3. Explain the interdisciplinary nature of geography.

Every branch of geography is linked with another subject: geomorphology with geology, climatology with meteorology, economic geography with economics, political geography with political science. Geography integrates knowledge from natural and social sciences.

Q4. Name the early writers on geography.

Hecataeus wrote "Ges Periodus", the first systematic description of the world; Ptolemy wrote "Geography" with an atlas; Strabo wrote the 17-volume "Geographica".

Q5. State career opportunities in geography.

GIS and remote sensing analyst, cartographer, urban and regional planner, climatologist, disaster management expert, data scientist, teacher/researcher and tourism professional.

Exam tip

Learn the branch–related-science pairs; they appear as "complete the correlation" or "find the odd one out".

Quick summary

The practical part of 12th Geography teaches how to collect, organise, analyse and show geographical data, and how to read toposheets. The practicals are: surveying through an app, data organisation, measures of dispersion (range, standard deviation), Spearman's rank correlation, divided circles, divided bar graphs, population pyramid, and toposheet interpretation (settlements, land use and occupations, transport and communication).

Key points

• Data collection: a questionnaire survey (can be made on a mobile app) collects primary data such as education, housing, assets and travel.
• Data organisation: check, clean and arrange data in tables and simple charts before analysis.
• Range = maximum value – minimum value. It is the simplest measure of spread.
• Standard deviation (SD) shows how far values are spread around the mean. Low SD → values close to mean (mean is reliable). High SD → values scattered.
• Rank correlation (Spearman) tells whether two variables increase or decrease together. Value lies between –1 and +1.
• Divided circle (pie diagram): each component's angle = (component value ÷ total) × 360°.
• Divided bar graph: one bar divided into parts in proportion (often in percentages) to show components.
• Population pyramid: horizontal bars for age groups; males on the left, females on the right; usually in percentages.
• Toposheet interpretation: read the type and pattern of settlements, land use (forest, agriculture, wasteland), occupations, and transport/communication lines using conventional signs and colours.

Important terms

• Dispersion – spread of data values around the average.
• Correlation – relationship between two variables.
• Positive correlation – both variables increase together; negative – one increases as the other decreases.
• Toposheet – Survey of India topographical map showing relief and cultural features.

Formulas

• Range = Highest value – Lowest value
• Mean x̄ = Σx ÷ n
• SD (σ) = √[Σ(x – x̄)² ÷ n]
• Spearman's rank correlation R = 1 – [6Σd² ÷ n(n² – 1)], where d = difference between the two ranks, n = number of pairs
• Angle of a sector = (value ÷ total) × 360°

5 important questions

Q1. Find the range and mean of daily distance travelled: 3, 7, 9, 10, 11 km.

Range = 11 – 3 = 8 km. Mean = (3 + 7 + 9 + 10 + 11) ÷ 5 = 40 ÷ 5 = 8 km.

Q2. Find the SD for the values 2, 4, 6, 8.

Mean = 20 ÷ 4 = 5. Deviations: –3, –1, 1, 3. Squares: 9, 1, 1, 9; sum = 20. SD = √(20 ÷ 4) = √5 ≈ 2.24.

Q3. Five villages have Σd² = 4 for ranks of literacy and income. Find R and interpret.

R = 1 – (6 × 4) ÷ [5(25 – 1)] = 1 – 24 ÷ 120 = 1 – 0.2 = 0.8. This is a high positive correlation: villages with higher literacy tend to have higher income.

Q4. A farmer grows crops on 40 ha: wheat 20 ha, jowar 10 ha, cotton 10 ha. Find the angles for a divided circle.

Wheat = (20 ÷ 40) × 360° = 180°; jowar = (10 ÷ 40) × 360° = 90°; cotton = 90°. Total = 360°.

Q5. What do you look for while interpreting settlements on a toposheet?

Type (compact or dispersed), pattern (linear, circular, radial etc.), site (near river, road, hill), size, and their relation to relief, water and transport routes.

Exam tip

Always write the formula, substitution and final answer with a one-line interpretation — marks are given for each step.