Waves, Coastal Processes, Population, and Biomes Revision

Flashcards covering coastal processes, population dynamics including urbanisation and overpopulation, and global biomes and climate patterns based on the Form 2 geography revision notes.

Fetch

The distance the wind blows over the surface of the sea which influences the height and strength of a wave.

Swash

The movement of water up the beach after a wave breaks.

Backwash

The return movement of water down the beach and back into the sea.

Destructive waves

Waves that erode the beach with a short wavelength, high-frequency rate, steep gradient, and a backwash stronger than the swash.

Constructive waves

Beach-building waves with a long wavelength, low-frequency rate, shallow gradient, and a swash stronger than the backwash.

Erosion

The wearing away of rock along the coastline, primarily caused by destructive waves.

Hydraulic action

A type of erosion where the sheer power of waves forces air into cracks in the rock, causing it to break apart.

Abrasion

A type of erosion where pebbles grind along a rock platform like sandpaper, eventually making the rock smooth.

Attrition

A type of erosion where rocks carried by the sea knock against each other, becoming smaller and more rounded.

Solution (Erosion)

A type of erosion where sea water dissolves certain rock types, such as chalk and limestone.

Solution (Transportation)

A method of transportation where minerals from dissolved rocks like chalk and limestone are carried in sea water as an invisible load.

Suspension

A method of transportation where small particles such as silts and clays are held in the flow of water.

Saltation

A method of transportation where small pieces of shingle or large sand grains are bounced along the sea bed.

Traction

A method of transportation where pebbles and larger material are rolled along the sea bed.

Longshore drift

The main process of transportation along the coast where waves approach at an angle and move material in a zig-zag movement.

Prevailing wind

The usual wind direction that influences the angle at which waves approach the beach during longshore drift.

Discordant coastline

A coastline with alternating bands of hard and soft rock at right angles to the coast.

Differential erosion

The process where softer rock is eroded more quickly than harder, more resistant rock.

Bays

Coastal features formed when softer rock is eroded more quickly, often characterized by sandy beaches.

Headlands

Features of harder, more resistant rock that erode slowly and are left protruding into the sea.

Wave-cut notch

A notch formed at the foot of a cliff by destructive waves using rock fragments for abrasion.

Wave-cut platform

A flat platform of rock left behind as a cliff retreats due to repeated collapse from undercutting.

Caves

Coastal features formed when repeated hydraulic action widens cracks in a headland.

Arch

Formed when continued erosion enlarges caves until they break through a headland.

Stack

An isolated pillar of rock left behind after a coastal arch collapses due to undercutting and gravity.

Stump

The base of a stack that has been further eroded by the sea.

Wave refraction

The process where wave energy is reduced as it bends around headlands or offshore islands.

Spit

A narrow ridge of sand built into open water where the coastline changes direction and wave energy decreases.

Recurved end

A feature of a spit formed by changes in wind and wave direction.

Bar

A ridge of sand formed when a spit extends fully across the mouth of a bay, trapping water behind it.

Lagoon

The body of water trapped behind a sand bar across a bay.

Tombolo

A ridge of sediment built by longshore drift and wave refraction that connects an offshore island to the mainland.

Hard engineering

The use of artificial structures, like concrete walls, to control natural coastal processes.

Sea walls

Concrete walls curved to reflect wave energy and placed at the cliff foot to prevent erosion; they cost approximately $\pounds 2,000$ per metre.

Soft engineering

A sustainable and natural approach to managing the coast that does not involve artificial structures.

Urbanisation

The process by which an increasing percentage of a country's population lives in towns and cities.

Rural-to-Urban Migration

The movement of people to cities seeking employment, higher wages, and better living conditions.

Natural Increase

Population growth that occurs when birth rates exceed death rates.

Demographic Transition Model

A model showing how birth rates and death rates change as a country develops over five stages.

Stage 1: High stationary

A stage with high birth and death rates leading to a stable population, seen in remote tribal groups.

Stage 2: Early expanding

A stage with high birth rates and falling death rates, leading to very fast natural increase, seen in the poorest LICs.

Stage 3: Late expanding

A stage where birth rates fall quickly and death rates fall slowly, seen in fast-industrialising countries.

Stage 4: Low stationary

A stage with low birth and death rates leading to very slow increase, seen in HICs like the UK and USA.

Stage 5: Decline

A stage where the birth rate falls below the death rate, typical of very highly developed countries with ageing populations.

Infant mortality rate

The number of children who die before their first birthday, which often influences birth rates.

Overpopulation

A state where there are more people in an area than can be supported by its resources and technology.

Makoko

A well-known informal settlement or slum in Lagos where many residents live in overcrowded conditions.

Lagos youth unemployment

A social issue in Lagos where approximately $35\%$ of young people are without formal work.

Informal economy

A sector involving $65\%$ of Lagos workers which limits tax income and job security for the city.

Lagos Healthcare Ratio

Lagos currently has only $1$ doctor per $2,500$ people, which is far above WHO recommendations.

PM2.5 pollution

Air pollutants in Lagos that are regularly above WHO safe levels due to traffic and open burning.

China's One Child Policy

A policy introduced in $1980$ and ended in $2015$ designed to slow population growth.

4-2-1 problem

An economic burden in China where One Child Policy meant one child could have to support two parents and four grandparents.

Sex-selective abortions

A negative result of China's One Child Policy caused by cultural preference for male children, leading to a gender imbalance.

Biomes

Large-scale ecosystems categorized by their climate and the plants and animals that live there.

Tundra

A cold, treeless biome in the far north with permafrost where only mosses, lichens, and low shrubs survive.

Permafrost

Permanently frozen ground in the Tundra that prevents tree growth.

Taiga (Boreal Forest)

A vast coniferous forest in the north with long cold winters and dense evergreen trees such as pine and spruce.

Temperate Forest

A mid-latitude biome with moderate rainfall and deciduous trees like oak and beech that shed leaves in autumn.

Desert

An extremely dry biome receiving less than $250\,mm$ of rain per year.

Savannah Grassland

A tropical biome of grasses and scattered trees like acacia with distinct wet and dry seasons.

Tropical Rainforest

A hot, humid biome receiving over $2,000\,mm$ of rain per year, supporting the greatest biodiversity on Earth.

Frontal rainfall

Rainfall that occurs when a warm air mass meets a cold air mass, causing warm air to rise, cool, and condense.

Convectional rainfall

Rainfall occurring in summer when the sun heats the land, creating rising pockets of warm air known as convection currents.

Cumulonimbus clouds

Large clouds formed by rapid convection that can produce heavy rainfall and thunderstorms.

Relief rainfall

Rainfall that occurs when warm, moist air is forced to rise over mountains, cooling and condensing.

Rain shadow

The dry area on the leeward side of a mountain after air has passed over and lost its moisture.

Climate graph

A graph used to show the average monthly temperature and precipitation for a specific location.

Latitude

An abiotic factor referring to the distance from the equator that determines the angle of the sun's rays.

Insolation

The amount of solar radiation reaching a given area; heat is more concentrated at the equator than at the poles.

Tricellular model

A model of global atmospheric circulation consisting of the Hadley, Ferrel, and Polar cells.

Hadley cell

Atmospheric circulation cells closest to the equator where heat rises and creates low pressure.

Ferrel cell

Atmospheric circulation cells located between $30^{\circ}$ and $60^{\circ}$ latitude.

Polar cell

The northernmost and southernmost atmospheric circulation cells where cold air sinks, creating high pressure.

Emergent layer

The tallest layer of the rainforest ($40\text{--}60\,m$) where trees are exposed to strong winds and intense sunlight.

Canopy

A dense ceiling of overlapping tree crowns ($20\text{--}40\,m$) that house the greatest variety of rainforest wildlife.

Undercanopy

A shaded rainforest layer ($5\text{--}20\,m$) with plants adapted to survive on limited filtered sunlight.

Forest floor

The dark, humid bottom layer of the rainforest ($0\text{--}5\,m$) receiving less than $2\%$ of sunlight.

Palm oil (Malaysia)

A major driver of deforestation in Borneo and Sabah; Malaysia is the world's second-largest producer.

Bauxite

A mineral export in Malaysia; in $2015$, Malaysia briefly became the world's top exporter of this material.

Bakun Dam

A Sarawak hydroelectric project completed in $2011$ that flooded $700\,km^2$ of rainforest.

Sarawak

A region in Malaysia where major development projects like the Bakun Dam and logging occur.

SCORE

A development programme in Sarawak under which further hydroelectric dams are planned, threatening forest areas.

Enhanced greenhouse effect

The phenomenon where increased greenhouse gases in the atmosphere trap more heat, leading to global warming.

Photosynthesis

The process by which trees store carbon dioxide; when trees are felled, this stored carbon is released.

Deforestation CO2 impact

Deforestation accounts for approximately $10\text{--}15\%$ of global carbon dioxide emissions.

IPCC

The intergovernmental body that warns halting deforestation is necessary to limit global warming to $1.5^{\circ}C$.

Penan people

An indigenous group in Sarawak displaced from their ancestral forest lands by activities like the Bakun Dam.

Timber exports

Valuable economic products for Malaysia, though illegal logging causes lost tax revenue.

Bornean orangutan

A critically endangered species in Malaysia whose primary threat is habitat loss due to deforestation.

Soil erosion (Malaysia)

The rapid degradation of land once tree cover is removed, often damaging coral reefs offshore in Sabah.

Toxic haze

A health and economic crisis caused by burning forests; in $2015$, it cost Southeast Asia an estimated $USD\,47\text{ billion}$.

Palm oil revenue

An economic driver that generates over $RM\,70\text{ billion}$ per year for Malaysia.

Malaysian population growth

A factor in urbanisation where the population doubled from $13\text{ million}$ in $1980$ to over $33\text{ million}$ today.

Ecotourism

Long-term economic potential that is damaged in Malaysia when biodiversity loss makes forests less attractive to visitors.

Short-wave radiation

Radiation from the sun that passes through the atmosphere to the Earth's surface.

Long-wave radiation

Heat given off by the Earth that is absorbed by greenhouse gases in the atmosphere.

Sub-Saharan Africa

A region where Savannah Grassland biomes are commonly found.

Deciduous

A term for trees like oak and beech that shed their leaves annually.

Coniferous

Trees like pine, spruce, and fir characterized by needles and cones, common in the Taiga biome.