Kerala Plus Two Geography (DHSE) cheat sheet

Human geography studies the relationship between human societies and the spaces they occupy; it is the spatial analysis of human activity, not a list of places.

Core subfields: population, settlement, economic, cultural, political, and social geography; each borrows methods from demography, economics, sociology, and planning.

Dichotomy with physical geography is methodological, not absolute: human geography uses the physical environment as a constraint-and-opportunity framework.

Environmental determinism (environment shapes society) versus possibilism (humans choose among environmental options) is the classic debate; modern practice favours possibilism with environmental limits.

Quantitative revolution (1950s-60s) introduced spatial science, models, and statistics; the later critical turn emphasised meaning, power, and perception (humanistic and radical approaches).

Key concepts: space versus place, region and regionalisation, scale, diffusion, and spatial interaction; distance decay and gravity models express interaction strength.

Neo-determinism (Stop-and-Go determinism) holds that humans can modify nature but within limits set by natural laws and carrying capacity.

Field study and mapping are the discipline's basic evidence tools: observation, questionnaire survey, and cartographic representation of spatial patterns.

Natural increase = birth rate − death rate (per 1,000); growth rate also adds net migration per 1,000 population.

Doubling time (years) ≈ 70 ÷ annual growth rate in percent; a 2% rate doubles population in about 35 years.

Demographic transition stages: high stationary (high BR, high DR), early expanding (BR high, DR falls), late expanding (BR falls), low stationary (both low), plus a possible declining stage.

Population pyramid shape reads structure: broad base and narrow apex = high fertility, young population; narrow base = ageing or declining fertility.

Dependency ratio = (population under 15 + over 64) ÷ working-age population (15-64) × 100.

Push factors drive migration away (unemployment, drought, conflict); pull factors attract (jobs, services, safety); intervening obstacles reduce flow.

Rural settlement types: compact/nucleated, dispersed, linear, circular, and star; dispersed settlement dominates in hilly, forested, or pastoral terrain.

Urban functions and land-use zones follow accessibility and rent: central business district at peak land value, residential and industrial zones outward; conurbation and megacity describe merged urban growth.

Primary activities directly extract from nature: hunting-gathering, pastoralism, fishing, mining, and agriculture; they dominate in low-income economies.

Shifting cultivation (slash-and-burn) is characterised by short cropping and long fallow; intensive subsistence farming by small holdings, high labour input, and high yield per hectare.

Plantation agriculture is capital-intensive, single-crop, export-oriented, and often colonial in origin (tea, rubber, coffee, sugarcane).

Secondary activities transform raw materials: manufacturing types include cottage, small-scale, large-scale, heavy, and footloose industries.

Weber's least-cost location theory: plant locates where transport plus labour costs are minimised, modified by agglomeration economies.

Tertiary activities provide services; quaternary involve knowledge and decision-making (research, finance, administration), and quinary involve high-level decision roles.

Industrial location factors: raw material, power, market, transport, labour, capital, and government policy; weight-losing industries (e.g. iron and steel) sit near raw materials.

High-technology industries cluster near research centres and skilled labour, not raw materials; they are footloose with respect to bulk inputs.

Transport modes compared on cost, speed, and flexibility: rail suits bulk over land, road suits short-haul and door-to-door, water is cheapest for bulk, air is fastest and costliest.

Ports and trans-shipment nodes act as break-of-bulk points where cargo changes carrier; hinterland is the area a port or node serves.

Communication types: personal (post, telephone, internet messaging) versus mass (radio, television, newspaper, internet broadcast).

Balance of trade = value of exports − value of imports; favourable when exports exceed imports, unfavourable when imports exceed exports.

Balance of payments covers trade plus invisibles (services, remittances, capital flows); a trade deficit can coexist with a payments surplus through remittances.

Trade blocs: free trade areas remove internal tariffs (e.g. SAARC/SAFTA, ASEAN); customs unions add a common external tariff; common markets add factor mobility.

Comparative advantage explains gains from trade: a country specialises where its opportunity cost of production is lower.

India's major exports include petroleum products, gems and jewellery, textiles, and engineering goods; major imports include crude oil, gold, and electronic goods.

Earth's interior layers: crust (continental ~35 km, oceanic ~5-10 km), mantle to 2,900 km, outer liquid core, and inner solid core; discontinuities are Moho and Gutenberg.

Plate boundaries: divergent (constructive, mid-ocean ridges), convergent (destructive, trenches and fold mountains), and transform (conservative, fault slip).

Weathering breaks rock in place (physical, chemical, biological); erosion transports the debris; mass wasting moves material downslope under gravity.

Fluvial landforms: V-shaped valley and waterfalls in youth, meanders and floodplains in maturity, deltas and ox-bow lakes in old stage.

Glacial landforms: cirque, arete, horn, U-shaped valley, moraine, drumlin, and outwash plain; aeolian forms: barchan, seif, yardang, and loess deposits.

Köppen climate groups: A tropical, B dry, C warm temperate, D cold, E polar; each letter subdivision reflects rainfall seasonality and temperature range.

Pressure and wind: winds flow from high to low pressure, deflected by Coriolis force (right in Northern Hemisphere, left in Southern); pressure gradient force sets speed.

Hydrological cycle stores and fluxes: evaporation, transpiration, condensation, precipitation, infiltration, runoff, and groundwater flow; a drainage basin is the unit of study.

River regime describes seasonal discharge variation; hydrograph plots discharge against rainfall, with lag time between peak rainfall and peak flow.

Soil profile horizons: O (organic litter), A (topsoil, humus-rich), B (subsoil, illuviation), C (weathered parent material), R (bedrock).

Soil-forming factors: parent rock, climate, relief, organisms, and time; leaching dominates in humid climates, salinisation in arid irrigated areas.

Major biomes: tropical rainforest, savanna, desert, temperate grassland, temperate forest, taiga (boreal), and tundra; each is defined by climate and dominant vegetation.

Biodiversity hotspots combine high species endemism with severe habitat loss; India's hotspots include the Western Ghats, Himalaya, Indo-Burma, and Sundaland (Nicobar).

Hazard types: tectonic (earthquake, tsunami, volcano), climatic (cyclone, flood, drought), and geomorphic (landslide, erosion); risk = hazard × vulnerability ÷ capacity.

Disaster management cycle: mitigation and preparedness before, response and relief during, recovery and rehabilitation after an event.

Environmental issues: ozone depletion by CFCs, acid rain from SO2 and NOx, and the enhanced greenhouse effect from CO2, CH4, and N2O.

Sustainable development balances present needs with future capacity; carrying capacity is the maximum population an environment can support indefinitely.

Physiographic divisions: Himalaya, Northern Plains, Peninsular Plateau, Indian Desert, Coastal Plains, and Islands.

Himalaya divisions from north to south: Trans-Himalaya (Karakoram, Ladakh), Greater Himalaya (Himadri), Lesser Himalaya (Himachal), and Shiwaliks; duns lie between Shiwaliks and Lesser Himalaya.

Northern Plains formed by alluvium of Indus, Ganga, and Brahmaputra systems; divisions are Bhabar, Tarai, Bhangar (older alluvium), and Khadar (newer alluvium).

Peninsular Plateau: Deccan Trap lava plateau (black soil), Central Highlands (Malwa, Bundelkhand), and Chota Nagpur plateau (mineral-rich).

West-flowing rivers (Narmada, Tapi, Mahi, Sabarmati) form estuaries; east-flowing rivers (Mahanadi, Godavari, Krishna, Kaveri) form deltas.

Himalayan rivers are perennial (snow and monsoon fed) and antecedent; peninsular rivers are seasonal and largely consequent on the plateau slope.

Ganga system: Bhagirathi and Alaknanda join at Devprayag to form the Ganga; tributaries include Yamuna, Ghaghara, Gandak, Kosi, and Son.

Brahmaputra is called Tsangpo in Tibet, Dihang on entry, and Jamuna in Bangladesh; it forms a braided channel and the Majuli river island.

India's climate is tropical monsoon; the monsoon is driven by differential heating, the ITCZ shift, and the tropical easterly jet and subtropical westerly jet.

Seasons: cold weather (Dec-Feb), hot weather (Mar-May, with Loo and Kalbaisakhi/Norwesters), southwest monsoon (Jun-Sep), and retreating monsoon (Oct-Nov, with Tamil Nadu rains).

Rainfall controls: Western Ghats windward side gets heavy rain, leeward side is rain-shadow (Pune, Bengaluru); Mawsynram and Cherrapunji record extreme northeast rainfall.

El Nino (warming of eastern Pacific) is generally linked to weaker Indian monsoon; La Nina to stronger monsoon.

Soils: alluvial (fertile, plains), black/regur (cotton, Deccan Trap, moisture-retentive clay), red (crystalline rock, iron-rich), laterite (heavy rain, leached), arid, forest, and peaty.

Soil conservation: contour ploughing, terracing, strip cropping, shelter belts, and check dams against gully erosion.

Natural vegetation types: tropical evergreen, tropical deciduous (monsoon forests, most widespread), thorn, montane, and mangrove/littoral forests.

Forest cover classification and mangrove ecology: Sundarbans is the largest mangrove area; mangroves buffer storm surge and cyclone damage.

India's 2011 Census population was about 1.21 billion; decadal growth 2001-2011 was 17.7%, with the natural increase share dominant.

Sex ratio (females per 1,000 males) was 943 in 2011; child sex ratio (0-6) was 919, showing a declining trend.

Density = population ÷ area (persons per km²); Bihar and West Bengal are among the densest states, Arunachal Pradesh among the lowest.

Literacy rate 2011: 74.04% overall; male 82.14%, female 65.46%; Kerala ranked highest among states.

Migration streams: intra-state rural-to-rural dominates in volume; rural-to-urban dominates in urbanisation impact; males migrate for work, females largely after marriage.

Human Development Index combines life expectancy, education (mean and expected years of schooling), and per capita income (GNI); Kerala ranks high on HDI within India.

Demographic dividend arises when the working-age share is large; it requires education, health, and job creation to convert into growth.

Population policy instruments include family welfare programmes, female education, and infant mortality reduction, which lower fertility.

Kerala lies between about 8°18'N and 12°48'N; the Western Ghats (Sahyadri) form the eastern boundary, the Arabian Sea the west.

Physiographic belts from east to west: highland (Western Ghats, above ~75 m), midland (undulating laterite), and lowland (coastal alluvium, backwaters).

Kerala's backwaters (Vembanad, Ashtamudi) are lagoon-estuarine systems; Vembanad is the largest lake in Kerala and a Ramsar site.

Kerala receives both southwest monsoon (June-Sep) and northeast monsoon (Oct-Nov) rain; annual rainfall is roughly 3,000 mm, among India's highest.

Kerala's soils: laterite (midland), alluvial (lowland), forest and hill soils (highland); high acidity and leaching are common, so liming is used.

Major crops: rubber, coconut, pepper, cardamom, tea, coffee, and paddy (Kuttanad below sea-level farming with bunds and pumps).

Field study sequence: define objective, choose site and sampling method, collect data (observation, questionnaire, transect), tabulate, map, analyse, and report limitations.

Silent Valley National Park is a biodiversity hotspot fragment in the Nilgiri Biosphere Reserve; it is known for tropical evergreen forest and lion-tailed macaque habitat.

Scale types: statement (verbal), representative fraction (RF, e.g. 1:50,000), and graphical (linear) bar; RF is unit-free and survives reproduction.

Large scale shows small area in great detail (1:10,000); small scale shows large area in less detail (1:1,000,000).

Contour lines join equal elevation; closely spaced contours mean steep slope, widely spaced mean gentle slope; V-shape pointing upstream marks a valley.

Grid references: eastings read before northings (right, then up); a four-figure reference locates a grid square, six-figure refines position within it.

Map symbols and conventional signs: blue for water, green for vegetation, brown for contours, black for cultural features.

Measurements: distance along a curved route uses a string or divider against the linear scale; area is estimated by grid-square counting.

Data interpretation: mean = sum ÷ number of items; median is the middle value; mode is the most frequent; range = maximum − minimum.

Cartographic choices: choropleth for density/ratio data by area, isopleth for continuous values (contours, isotherms), dot map for distribution, and pie/bar for composition.