UPMSP Intermediate Geography - Code 129 key terms

The overall wearing away of the land surface by weathering, mass movement, erosion and transport acting together over long periods, lowering relief and reducing land to gentler slopes.

The in-place breakdown of rock by physical, chemical or biological processes without any movement of the broken material. It prepares rock for removal but is not itself erosion.

The loose, fragmented layer of broken rock and mineral grains lying on solid bedrock, produced mainly by weathering. Soil develops in the upper part of this layer.

The removal and transport of weathered material by a moving agent such as running water, wind, glacier or waves. It shapes valleys, coasts and deserts by cutting and carrying debris.

The lowest elevation to which a stream can erode its bed, normally sea level for rivers reaching the coast. Approaching it, erosion gives way to deposition and gradients flatten.

The smoothly concave long profile of a river in which slope decreases downstream and the energy supplied just balances the load carried, so neither net erosion nor net deposition occurs.

All material carried by a stream: dissolved matter in solution, fine particles in suspension, and coarser sand and gravel rolled or bounced along the bed as bed load.

The laying down of transported sediment when a river, wind, glacier or wave loses energy. It builds features such as floodplains, deltas, sand dunes, moraines and beaches.

Incoming solar radiation received at the Earth's surface. Its intensity varies with latitude, season and angle of the sun, and it is the main energy source driving atmospheric and oceanic circulation.

The proportion of incoming solar radiation reflected back to space by a surface. Fresh snow reflects most, dark oceans and forests least, so surface cover affects local and global energy balance.

The rate at which atmospheric pressure changes over horizontal distance. The steeper the change, the stronger the resulting wind, which blows from high toward low pressure.

An apparent deflecting force caused by the Earth's rotation, turning moving air and water to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, strongest at the poles.

A narrow, fast-moving band of upper-troposphere westerly wind near the tropopause. Its meanders steer mid-latitude weather systems and influence the timing of the Indian monsoon.

A seasonal reversal of prevailing wind direction caused by differential heating of land and sea, bringing a wet summer and dry winter to South and Southeast Asia, including India.

A dry area on the leeward side of a mountain range, where descending air has already lost its moisture on the windward slope. It explains dry interiors behind coastal ranges.

Rain produced when moist air is forced to rise over hills or mountains, cools, condenses and precipitates on the windward slope, leaving the leeward side drier.

The slow, deep global movement of ocean water driven by differences in temperature and salinity, which change density. It carries heat between latitudes and mixes the deep ocean.

A large-scale, persistent horizontal flow of seawater, driven by winds, density differences and the Earth's rotation. Warm and cold currents moderate coastal climates and support fisheries.

The rise of cold, nutrient-rich water from depth toward the ocean surface, usually where winds push surface water offshore. It fertilises plankton growth and supports rich fishing grounds.

A very large ecological region with a characteristic climate, vegetation and animal life, such as tropical rainforest, savanna, desert, temperate grassland or tundra. Its boundaries broadly follow climate zones.

A community of living organisms interacting with one another and with their non-living surroundings, exchanging energy and nutrients. Examples include a pond, a forest patch or a river basin.

The sequence in which energy passes from producers such as green plants to herbivores and then to carnivores and decomposers. Each step loses much energy as heat.

The average number of people living per unit area, usually persons per square kilometre. It reveals crowding and resource pressure but hides uneven distribution within the area.

The pattern in which people are spread over an area, from dense river plains and coasts to sparse deserts and high mountains. It results from physical, economic and historical factors.

A model describing how birth and death rates change as a society develops, moving from high both, through rapid growth as deaths fall, to low both and stable population.

The potential economic gain when a country's working-age population is large relative to dependants, provided enough jobs and skills exist to employ them productively.

The number of females per thousand males in a population. It reflects social attitudes, health care and migration patterns and is a key indicator of gender balance.

Conditions that drive people away from a place, such as unemployment or conflict, and conditions that attract them elsewhere, such as jobs or better services. Together they explain migration streams.

The movement of people from one place to another to settle, temporarily or permanently. It may be internal or international, voluntary or forced, and it changes both source and destination populations.

Farming mainly to feed the farmer's own household, with little surplus for sale. It uses small plots, family labour and simple tools, and is common in densely peopled humid regions.

Large-scale farming organised to sell produce for profit, using hired labour, machinery, fertilisers and improved seed. Output is high per worker and is linked to markets and transport.

A form of subsistence farming in which forest is cleared and burnt, cropped for a few years, then abandoned as fertility falls while the farmer moves to a new plot.

Large estates growing a single cash crop such as tea, coffee, rubber or sugarcane for export, usually in tropical areas with abundant labour and good transport to ports.

Work that directly uses natural resources, such as farming, fishing, forestry, mining and quarrying. Its products are raw materials for other sectors.

Work that transforms raw materials into manufactured goods, as in factories, craft workshops, refineries and power generation. It adds value to primary products.

Work that provides services rather than goods, including transport, trade, banking, education, health and tourism. It is the fastest-growing sector in most developed economies.

Highly specialised service work involving knowledge, research, information and decision-making, such as scientific research, consultancy, software design and high-level administration.

The siting of a factory where costs are lowest and access to markets best, weighing raw materials, power, labour, transport, capital, government policy and agglomeration advantages.

The rising share of a population living in towns and cities, driven by rural-to-urban migration and natural growth. It brings economic opportunity but also pressure on housing and services.

A continuous built-up area formed when several expanding towns merge, such as a large metropolitan belt. Boundaries between the original towns become hard to see.

A city that is disproportionately larger than the second city of its country and dominates national economic, political and cultural life, often producing uneven urban growth.

A composite measure combining life expectancy, education and per-capita income to compare average wellbeing across countries. It ranges from zero to one, higher values meaning better development.

The boundary of the area drained by a river and its tributaries, also called a drainage divide. Everything inside it drains to a common outlet.

The whole area from which a river system collects water and sediment, bounded by a watershed. Its size, shape, relief and climate control the river's flow.

The arrangement of a river and its tributaries on the land, shaped by rock type, structure and slope. Common types include dendritic, trellis, radial and centripetal.

A ridge or high ground separating two adjacent drainage basins, so that rain falling on either side flows into different river systems. It may be a mountain crest or a low swell.

A vertical section through soil from surface to bedrock, showing horizons such as dark humus topsoil, leached middle layers and weathered parent material below.

The downward washing of soluble salts and fine particles through soil by percolating rainwater, leaving upper layers depleted. It is strong in heavy-rainfall areas.

The removal of fertile topsoil by wind or running water faster than it can form, reducing fertility and causing silting downstream. It is worsened by deforestation and steep slopes.

Ploughing along lines of equal elevation so that furrows run across the slope, slowing runoff and trapping soil. It is a common soil-conservation practice on hilly farmland.

Plant cover that grows without human planting, determined mainly by climate and soil. It includes forests, grasslands, scrub and mangroves, though much has been cleared.

A line on a map joining points of equal height above sea level. Closely spaced contours show steep slopes, widely spaced ones gentle slopes.

A printed figure on a map giving the exact elevation of a specific point. It supplements contours by marking summits, road junctions and other precise heights.

The ratio between distance on a map and the corresponding distance on the ground, shown as a fraction, a statement or a bar. It allows real distances to be measured from the map.

A side-view diagram drawn from a map by plotting heights along a chosen line, used to show relief, slopes and features such as valleys or ridges in profile.