Discovering Britain

Canal

An artificial waterway constructed to allow the passage of boats or ships inland or to convey water for irrigation. While the Romans created navigable canals to link rivers, the heyday of British canal building was the mid-eighteenth to mid-nineteenth century when they were instrumental in the Industrial Revolution before being largely replaced by the railways. The UK currently has around 2,200 miles of navigable canals and rivers.

Chalk

A soft, white, porous sedimentary rock, which is a form of limestone. Formed in Northern Europe around 90 million years ago when the area was covered by a great sea. The skeletal remains of marine organisms accumulated over time and were compressed, eventually becoming chalk rock. Where chalk ridges meet the sea, there are usually steep cliffs, such as the White Cliffs of Dover. Chalk hills, known as chalk downland, usually form where bands of chalk reach the surface at an angle, so forming a scarp or steep slope.

Chalk stream

A particular kind of stream occurring where the underlying geology changes from chalk to clay. Clay is non-porous so groundwater cannot pass through it. Water emerges just above the clay layer as a spring and continues as a chalk stream.

Cliff

A series of high, steep or overhanging faces of rock running parallel to the shoreline such as the White Cliffs of Dover.

Climate

The generally prevailing meteorological conditions of a region over the long term, comprising temperature, humidity, atmospheric pressure, wind and rainfall. Not to be confused with weather, which is the short-term variations in these meteorological conditions.

Climate change

A significant and lasting change in climate over periods ranging from decades to millions of years.

Cloudburst

An extreme amount of heavy rainfall, sometimes with hail and thunder, which normally lasts no longer than a few minutes but is capable of causing floods.

Clunch

A term for traditional building material used mainly in eastern England and Normandy. It tends to be soft chalk or clay and comes in as irregular lumps of rock either picked up from the fields, or quarried from the ground. The term is sometimes used more generically in other parts of England for any soft and aggregate-based vernacular building material which is used as a poor substitute for stone.

Coastal defences

Physical objects and engineering techniques used to protect the coastline from erosion or flooding.

Coastal deposition

The laying down of material by the action of the action of waves and tides. This can create landforms such as beaches, dunes, spits and sandbanks.

Coastal erosion

The wearing away and removal of material by the action of the action of waves and tides or by human interference. This can cause cliff collapse.

Colliery

A coal mine and the buildings and equipment associated with it.

Combe / coombe

A type of valley or hollow, commonly found in chalk landscapes. Also seen in place names in Southern England.

Confluence

The point at which two or more bodies of water meet, for example where two streams merge into a single stream or where a tributary stream joins a larger river.

Conifer

Type of tree or shrub which bears male and female reproductive organs in separate cones (strobili) rather than in flowers; of great economic value, primarily for timber and paper production, as they are relatively fast-growing.

Conservation Area

An area (usually urban) considered worthy of preservation or enhancement because of its special architectural or historic interest. More than 8000 have been designated in the UK.

Contour / Contour line

A line which joins points of equal height above a given level, such as mean sea level. On a map, the distribution of contour lines and the spacing between them is indicative of landscape features such as valleys, hills and slopes.

Coral

A rocklike deposit formed in warm seas consisting of the calcium carbonate secreted by corals. Where deposits accumulate they form reefs. They are found in the British geological ercord from a period when part of the land was under a warm tropical sea.

Cove

A small type of bay typically with a small opening to the sea and thus quite sheltered from the wind and waves. A classic example is Lulworth Cove in Dorset.

Coppicing

A traditional method of woodland management whereby young tree stems are repeatedly cut down to near ground level. In subsequent growth years, many new shoots will emerge, and, after a number of years the coppiced tree, or stool, is ready to be harvested, and the cycle begins again. This process maintains trees at a juvenile stage, and a regularly coppiced tree will never die of old age. In the days of iron production in England, most woods in iron-making regions were managed as coppices, with the wood being made into charcoal fuel. Coppicing has the effect of providing a rich variety of habitats, as the woodland always has a range of different-aged coppice growing in it, which is beneficial for biodiversity.

Creek

In the UK, a creek is a tidal inlet, typically in a saltmarsh or swamp, which rises and falls with the tide. In other countries, such as North America, Australia and New Zealand, a creek refers to a small to medium sized natural stream.

Cretaceous

A period of geological time 144 million to 65 million years ago characterised by a relatively warm climate and high sea level, when the seas were populated with now-extinct marine reptiles and the land by dinosaurs.

Crenellation

A building design used on fortified walls with regular gaps for firing arrows, guns or other weapons.

Crustaceans

A group of anthropods (invertebrate animals with an external skeleton and segmented body) including crabs, lobsters, crayfish, shrimp, krill and barnacles.

Culvert

A device used to channel water, particularly underneath a road, railway or embankment.

Culverting

The covering or diversion of rivers and streams by man-made structures; for example rivers passing through urban areas are often culverted in pipes beneath streets and buildings.