WBBSE Madhyamik Geography flashcards
WBBSE Madhyamik Geography · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Earth's crust
- The outermost solid layer of the Earth, made of silicate rock; it is roughly 5–10 km thick under oceans and 30–70 km thick under continents.
- Weathering versus erosion
- Weathering is the in-place breakdown of rock by physical, chemical, or biological processes; erosion removes and transports the broken material by water, wind, or ice.
- Oxbow lake
- A crescent-shaped lake formed when a river meander is cut off from the main channel by deposition of a neck of land, typical of a river's mature stage.
- Cirque
- A bowl-shaped hollow eroded at the head of a glacier by frost shattering and plucking; when filled with water it becomes a tarn lake.
- Barchan dune
- A crescent-shaped sand dune formed by wind deposition, with gentle windward slope and steep leeward slip face; horns point downwind.
- Monsoon
- A seasonal reversal of prevailing wind direction caused by differential heating of land and sea, shifting pressure belts, and the Himalayan barrier, bringing heavy summer rain.
- P-wave and S-wave
- P-waves are longitudinal, fastest, and travel through solids and liquids; S-waves are transverse, slower, and cannot pass through liquids.
- Soil profile horizons
- Vertical layers of soil: O (organic litter), A (topsoil with humus), B (subsoil of illuviation), C (weathered rock fragments), and R (bedrock).
- Western Ghats
- A continuous, higher mountain range along India's west coast, reaching Anamudi (2,695 m); it blocks the southwest monsoon and causes heavy windward rainfall.
- Bhangar and khadar
- Bhangar is older, higher alluvium with calcareous nodules; khadar is newer, lower alluvium renewed by annual floods in the Ganga plain.
- Sundarbans
- A tidal halophytic mangrove forest in the Ganga-Brahmaputra delta of West Bengal and Bangladesh, a UNESCO World Heritage Site and tiger reserve.
- Damodar Valley
- West Bengal's mineral and industrial belt, with coal reserves and multipurpose dams at Tilaiya, Konar, Maithon, and Panchet under the DVC.
- Laterite soil
- A leached red soil of the Rarh region formed by heavy rainfall dissolving silica; it is acidic, low in fertility, and suited to tea and cashew.
- Farakka Barrage
- A barrage on the Ganga in West Bengal that diverts water into the Hooghly to flush silt and maintain navigation to Kolkata port.
- Tropic of Cancer in Bengal
- The 23.5°N parallel crosses West Bengal near Krishnanagar, giving the state a tropical monsoon climate with a marked dry winter.
- Rarh plain
- The lateritic upland of western and central West Bengal between the Chota Nagpur plateau and the Ganga delta, drained by the Damodar and its tributaries.
- Primary activity
- An economic activity that directly extracts natural resources, such as farming, fishing, forestry, and mining, forming the base of the economy.
- Plantation agriculture
- Large-scale commercial farming of a single crop such as tea, coffee, or rubber, needing a tropical climate, abundant cheap labour, and good transport to markets.
- Population density
- The number of persons per unit area, calculated as total population divided by total area; India's 2011 Census recorded about 382 per sq km.
- Sex ratio
- The number of females per 1,000 males in a population; Kerala records a high ratio, while Haryana and Punjab record low ratios.
- Demographic dividend
- The economic advantage from a large share of working-age population; it produces growth only when education, skills, and jobs expand.
- Industrial location factors
- Conditions guiding where industry is sited: raw material, power, transport, labour, market, capital, and government policy.
- Human Development Index
- A composite measure of development combining life expectancy, education (mean and expected years of schooling), and per-capita income.
- Sustainable development
- Development that meets present needs without compromising the ability of future generations to meet theirs, through renewable energy and resource recycling.
- Representative fraction
- A scale expressed as a ratio such as 1:50,000, meaning one unit on the map equals 50,000 of the same units on the ground; it is unit-independent.
- Scale conversion rule
- At 1:50,000, one centimetre on the map equals 0.5 km on the ground; at 1:25,000, one centimetre equals 0.25 km.
- Contour lines
- Lines joining points of equal elevation; closely spaced contours indicate a steep slope, widely spaced contours a gentle slope.
- Depression on a map
- A contour pattern of closed loops with hachures or decreasing values inward, showing a hollow lower than the surrounding land.
- Grid reference order
- A map location read as easting first, then northing, from the grid lines on a topographical sheet.
- Dendritic drainage
- A tree-like stream pattern developed on uniform rock, where tributaries join the main river at acute angles in many directions.
- Magnetic declination
- The angle between true north and magnetic north at a place; it is stated in the topographical sheet's marginal information and must be applied to bearings.
- Cross-section drawing
- A profile drawn by plotting elevations along a straight line between two map points against a chosen vertical scale, showing relief shape.