Download Theme 2 – Natural Environment

Theme 2 – Natural Environment
Glossary card
Anticyclone - A high pressure weather system. Average sea level pressure at the centre of the
system is usually above 1000 millibars.
Agent of erosion - A force responsible for eroding the Earth’s surface e.g. wind, water, ice.
Aquifer - A rock structure which will hold water. Water can be abstracted from the rock by
drilling boreholes.
Arch - A natural breach or hole formed by wave erosion on each side of a headland. Two caves
usually meet to form the arch.
Attrition - The wearing away of rock fragments as they rub against each other during
transportation.
Backwash - The movement of water back to the sea after a wave has broken on the shore. The
movement is at right angles to the coast.
Beaufort Scale - A scale of wind speed ranging from 0 (Calm) to 12 (Hurricane). A figure of 12
is over 117mph (73kph).
Biomes - Large ecosystems at the global scale where the climate and vegetation is uniform.
Cave - An opening within a rock. Caves form in headlands where weaker bands of rock are
eroded by wave action.
Corrasion - The eroding away of rock surfaces by other (Abrasion) pieces of rock being carried
by rivers or by the sea.
Climate - The average weather conditions over a long period – at least 30 years. Temperature
and precipitation are the most often used climate data and are shown on climate graphs.
Cold front - The boundary where a cold air mass meets and pushes into a warm air mass. This is
usually found in the mid-latitudes of the northern hemisphere as part of a depression.
Deposition - The laying down of material such as mud or sand on the sea floor and river beds.
Distributaries - The many channels that a stream or river splits into when it meets a lake or sea
and forms a delta.
Delta - A landform, often triangular in shape, that develops where a river meets a slow-moving
body of water such as a lake or ocean. Deposition of sediment eventually builds up above the
water level forcing the river to split into distributaries to form a delta.
Depression - A low-pressure weather system often found in the mid-latitudes of the northern
hemisphere where a warm tropical air mass pushes into a cold arctic air mass. Warm air rises to
give low pressure at the centre of the weather system. This is usually less than 1000 millibars.
Ecosystem - A system of links between plants and animals (the living community) and the
habitats where they live, including the non-living environment.
Estuary - The broad seaward side of a river mouth where there is a mix of fresh water and sea
water.
Flood plain - A flat area of land on both sides of a river made up of sediment deposited when
the river floods.
Groyne - A low barrier of concrete or wood built out into the sea from the coast. By trapping
sand it slows down the movement of longshore drift.
Hydrograph - A graph which shows the pattern of a river's discharge. It is measured in cubic
metres per second (cumecs) over a period of time.
Hydrosphere - This is made up of all the stores and flows of water in gas, liquid or solid state
e.g. clouds, rivers, ice.
Hydraulic action - The trapping of air under pressure by water in rivers or the sea. The energy
release is explosive and helps erode the rock.
Impermeable - These rocks do not allow water to pass through. They are watertight e.g. clay.
Infrastructure - The structure of communications and services required to support economic
development e.g. power supplies, education, health, transport.
Input - That which is put in or taken into a system. In the hydrological cycle, precipitation is an
input to the drainage basin.
Irrigation - The artificial supply of water to land by such means as channels, sprinklers,
hosepipes.
Leaching - A chemical reaction which results in nutrients in the soil being replaced by hydrogen
from rainfall. Nutrients are lost from the soil or moved deeper down the soil profile.
Levée - The raised banks of a river usually found in the lower course. They may be formed
naturally by regular flooding or be built up by people to protect the area against flooding.
Longshore drift - The zigzag movement of sediment along a shore caused by waves going up the
beach at an oblique angle (wash) and returning at right angles (backwash).
Monsoon - It is a seasonal change of wind direction. The monsoon refers to both dry and wet
seasons although its common use refers to the wet season only.
Permeable - These rocks allow water to pass through them e.g. chalk, limestone.
Porous - These rocks contain many small air spaces e.g. chalk. Most porous rocks are permeable.
Precipitation – Moisture that falls out of the sky (rain, sleet, snow and hail).
Prevailing wind - The direction from which the wind blows into an area for most of the year.
Solution - The dissolving of rock material in water. (Corrosion)
Spit - A sand ridge that is joined to the coast at one end and juts out into the sea usually with a
curve at the other end.
Stack - An isolated pillar of rock separated from a headland. Stacks are usually formed by the
collapse of an arch.
Swash - The advance of sea water up a beach after the breaking of a wave.
Sustainable - Capable, by careful use and management, of being maintained, used and enjoyed
by future generations.
Temperature range - The difference between the highest and lowest temperature during a
fixed period of time
Tundra - The biome in Alaska, northern Canada, northern Europe and Asia where the ground is
permanently frozen for most of the year. Lichen, moss, grasses and dwarf shrubs and trees can
grow here.
Warm front -The boundary where a mass of advancing warm air meets a mass of cold air. The
lighter, warm air rises over the cold air.
Weather - Short-term day-to-day changes in the atmosphere. Weather recording usually
includes rainfall, temperature, cloud cover, wind speed and direction.
Weathering - The breakdown of rock surfaces into smaller particles by the action of the
weather, plants and animals. Weathering takes place in situ or on the spot. It does not involve
large-scale removal of material.
Water (Hydrological) Cycle - The constant recycling of water between the atmosphere and the
Earth’s surface.
Water deficit - This exists where water supply is lower than demand.
Water surplus - This exists where water supply is greater than demand.
Water table - The level below which the ground is saturated with water. It can vary according
to the season.