RBSE VU Geography cheat sheet

Earth's layers by depth: crust (0–~35 km continental, ~5–10 km oceanic), mantle (~35–2,900 km), outer core (2,900–5,150 km, liquid), inner core (5,150–6,371 km, solid).

Crust–mantle boundary is the Mohorovičić discontinuity (Moho); mantle–core boundary is the Gutenberg discontinuity; inner–outer core boundary is the Lehmann discontinuity.

P-wave (primary) velocity drops sharply at the Gutenberg discontinuity because the outer core is liquid; S-waves cannot pass through the outer core, producing the S-wave shadow zone beyond ~103°.

Isostasy: continental crust (granitic, density ~2.7 g/cm³) floats higher on denser mantle (~3.3 g/cm³) than oceanic crust (basaltic, ~3.0 g/cm³).

Geothermal gradient averages ~25–30 °C per km in the crust; heat flow drives mantle convection, the proposed mechanism for plate motion.

Wegener's continental drift evidence: jigsaw fit of continents, matching fossils (Glossopteris), glacial striations, and rock strata across the Atlantic.

Plate boundaries: divergent (mid-ocean ridges, rift valleys), convergent (subduction, fold mountains, island arcs), transform (San Andreas Fault).

Earthquake focus is the subsurface origin; epicenter is the point directly above it; P-waves arrive first, then S-waves, then surface waves.

Weathering types: physical (frost wedging, exfoliation, salt crystallization), chemical (hydrolysis, oxidation, carbonation), biological (root wedging, burrowing).

Mass wasting classes by speed and water content: creep (slowest), solifluction, mudflow, landslide, rockfall (fastest).

Fluvial landforms: V-shaped valley, gorge, waterfall, meander, oxbow lake, floodplain, alluvial fan, delta, peneplain.

Karst landforms in limestone: sinkhole, doline, uvala, polje, stalactite, stalagmite, cavern - formed by carbonation solution.

Glacial landforms: erosional (cirque, arête, horn, U-shaped valley, hanging valley, roche moutonnée); depositional (moraine, drumlin, esker, kame, outwash plain).

Aeolian landforms: barchan (crescent dune, horns downwind), seif/longitudinal dune, yardang, zeugen, mushroom rock, loess deposits.

Coastal landforms: erosional (cliff, wave-cut platform, sea cave, arch, stack); depositional (beach, spit, bar, tombolo, lagoon).

Davis's cycle of erosion: youth (steep V-valleys), maturity (wide valleys, meanders), old age (peneplain); Penck proposed an alternative slope-retreat model.

Atmospheric layers: troposphere (weather, lapse rate ~6.5 °C/km), stratosphere (ozone layer), mesosphere (coldest), thermosphere, exosphere.

Composition by volume: nitrogen ~78%, oxygen ~21%, argon ~0.93%, CO₂ ~0.04%; water vapor varies 0–4%.

Insolation is concentrated at low latitudes; the equator receives near-vertical rays, poles oblique rays, causing the latitudinal heat imbalance.

Pressure belts: equatorial low (ITCZ), subtropical highs (~30°), subpolar lows (~60°), polar highs; global winds blow from high to low pressure, deflected by Coriolis force.

Trade winds (NE in northern hemisphere, SE in southern) blow toward the equator; westerlies in mid-latitudes; polar easterlies near poles.

Monsoon is a seasonal wind reversal: summer southwest monsoon brings rain to India; winter northeast monsoon is dry over most of India but brings rain to Tamil Nadu.

Cyclones: tropical cyclones form over warm oceans (>26.5 °C) between 5° and 20° latitude, with low pressure centers, inward spiraling winds, and an eye.

Climate classification: Köppen uses temperature and precipitation letters (A tropical, B dry, C temperate, D continental, E polar).

Hydrological cycle components: evaporation, transpiration, condensation, precipitation, infiltration, runoff, groundwater recharge, and storage.

Ocean water: average salinity ~35 ppt; salinity is highest in subtropical regions (high evaporation) and lowest near equator and river mouths.

Ocean temperature decreases with depth; the thermocline is the transition layer between warm surface water and cold deep water.

Ocean currents: warm currents (Gulf Stream, Kuroshio) flow from low to high latitudes; cold currents (Labrador, Peru/Humboldt) flow from high to low latitudes.

Tides: spring tides occur at new and full moon (sun and moon aligned); neap tides at quarter moons (forces at right angles).

Groundwater: water table is the upper limit of saturation; aquifer is a permeable rock storing/transmitting water; aquiclude is impermeable.

India's water resources: major river basins include Ganga, Brahmaputra, Indus, Godavari, Krishna, Narmada, and Cauvery; per capita availability is declining.

Watershed management: contour bunding, check dams, rainwater harvesting, and recharge pits improve groundwater and reduce runoff.

Biosphere is the zone of life spanning the lower atmosphere, hydrosphere, and upper lithosphere; it interacts with the other spheres.

Ecosystem components: producers (autotrophs), consumers (herbivores, carnivores, omnivores), decomposers; energy flows unidirectionally and nutrients cycle.

Ecological pyramid types: numbers, biomass, and energy; energy pyramid is always upright due to the 10% law (Lindeman).

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

Soil formation factors (Jenny): parent material, climate, organisms, relief, and time (CLORPT).

Soil types in India: alluvial (most fertile, Indo-Gangetic plain), black/regur (cotton soil, Deccan), red (iron-rich), laterite (leached, high rainfall), arid (sandy, Rajasthan), mountain soil.

Biomes: tropical rainforest, savanna, desert, temperate grassland, taiga, tundra; each defined by climate and dominant vegetation.

Biodiversity hotspots in India: Western Ghats, Eastern Himalaya, Indo-Burma, Sundaland (Nicobar); India has ~8% of global species.

Demographic transition stages: high birth/high death (stage 1), early expanding (stage 2), late expanding (stage 3), low birth/low death (stage 4), decline (stage 5).

Population density = total population / total land area; India's density ~480 persons/km² (2021 census projections).

Population pyramid shapes: expansive (young, high birth), constrictive (aging, low birth), stationary (stable).

Push factors of migration: unemployment, poverty, conflict, disasters; pull factors: jobs, education, healthcare, better living standards.

Rural settlements: compact/nucleated, dispersed, linear, circular; urban settlements classified by size and function.

Urbanization trends: India's urban population growing rapidly; million-plus cities and megacities (Delhi, Mumbai, Kolkata, Chennai) dominate.

Malthusian theory: population grows geometrically, food arithmetically; critics argue technology raises food supply.

Sex ratio, literacy, and dependency ratio are key demographic indicators; dependency ratio = (young + old) / working-age population.

Agriculture types: subsistence, commercial, plantation, shifting cultivation, intensive farming, mixed farming, and pastoralism.

Crop requirements: rice needs high rainfall and temperature; wheat needs cool growing season and moderate rain; cotton needs black soil and 210 frost-free days.

Green Revolution (1960s–70s): high-yielding varieties, irrigation, fertilizers, and pesticides boosted wheat and rice production in Punjab, Haryana, and western UP.

Industrial location factors: raw material, power, labor, market, transport, capital, and government policy (Weber's least-cost theory).

Industrial regions in India: Mumbai-Pune, Hooghly, Gujarat, Chhotanagpur, and southern region; iron and steel at Jamshedpur, Bhilai, Rourkela, Durgapur.

Transport modes: road (flexible, door-to-door), rail (bulk, long distance), water (cheapest for heavy goods), air (fastest, costly), pipelines (liquids/gases).

Trade: balance of trade = exports − imports; favorable surplus, unfavorable deficit; India's major exports include petroleum products, gems, and textiles.

Special Economic Zones (SEZs) and industrial corridors (Delhi–Mumbai, Chennai–Bengaluru) promote manufacturing and exports.

India's physiographic divisions: Himalayan mountains, Northern Plains, Peninsular Plateau, Coastal Plains, Islands (Andaman & Nicobar, Lakshadweep).

Rajasthan: largest state by area (~342,239 km²); Thar Desert covers ~60% of the state; Aravalli Range runs southwest to northeast.

Rajasthan climate: arid to semi-arid; low rainfall (100–400 mm in west), high temperature variation; Loo winds in summer.

Rivers of Rajasthan: Chambal (only perennial), Luni (inland drainage, saline below Balotra), Banas, Mahi, Sabarmati; Indira Gandhi Canal irrigates the Thar.

Rajasthan economy: agriculture (bajra, wheat, mustard, cotton), mining (zinc at Zawar, copper at Khetri, marble at Makrana), tourism, and handicrafts.

Major cities: Jaipur (capital, planned city), Jodhpur (Blue City), Udaipur (City of Lakes), Bikaner, Kota (education hub), Ajmer.

Aravalli is one of the world's oldest fold mountains; it acts as a barrier to desert expansion and influences rainfall patterns.

Rajasthan's Sambhar Lake is India's largest inland saline lake; Keoladeo National Park (Bharatpur) is a UNESCO World Heritage wetland.

Map scale types: representative fraction (1:50,000), verbal (1 cm = 1 km), and graphical (bar scale).

Large-scale maps show small areas in detail; small-scale maps show large areas with less detail.

Latitude lines run east-west and measure north-south position; longitude lines run north-south and measure east-west position; Prime Meridian is 0°.

Topographic map colors: brown for contours, blue for water, green for vegetation, black for cultural features, red for roads/boundaries.

Contour lines connect points of equal elevation; closer contours indicate steeper slope; V-shape pointing upstream indicates a valley.

Remote sensing: passive sensors detect reflected sunlight (visible, infrared); active sensors emit their own energy (radar, LiDAR).

Spatial resolution is the smallest object detectable; temporal resolution is revisit frequency; spectral resolution is number of wavelength bands.

GIS layers: vector (points, lines, polygons) and raster (grid cells); overlay analysis, buffering, and spatial interpolation are common operations.

Sustainable development (Brundtland Report, 1987): meeting present needs without compromising future generations' ability to meet theirs.

Climate change: greenhouse gases (CO₂, CH₄, N₂O, CFCs) trap outgoing longwave radiation; global average temperature has risen ~1.1 °C since pre-industrial times.

Disaster types: natural (earthquake, flood, cyclone, drought, landslide) and human-induced (industrial accidents, fires); vulnerability depends on exposure and coping capacity.

Disaster management cycle: mitigation, preparedness, response, recovery, and rehabilitation.

India's disaster-prone zones: seismic zones II–V (V highest risk), flood-prone Indo-Gangetic plains and coastal areas, cyclone-prone east coast, drought-prone Rajasthan and Marathwada.

Environmental issues: air pollution (PM2.5, PM10), water pollution, deforestation, soil degradation, and biodiversity loss.

Sustainable Development Goals (SDGs): 17 goals adopted by the UN in 2015, targeting poverty, hunger, health, education, climate, and ecosystems by 2030.

Mitigation strategies: renewable energy, afforestation, rainwater harvesting, waste management, and disaster-resilient infrastructure.