Abstraction – the act of pumping or removing water from the groundwater or a river

Aquifer – underground, permeable rock which can act as a store of water

Canalising – converting a river into a canal-like waterway, usually by installing artificial banks and/or bed and straightening the channel

Dredging – scooping or digging out of the river bed to deepen the channel

Groundwater – Underground water, held in saturated rock or soil

Invasive non-native species – animals or plants found outside their natural distribution, and which cause harm to the environment, people and/or the economy

Macrophytes - a non-microscopic aquatic plant growing in or near water

Meander – a bend in a river. Meanders add variety to a river’s flow, and can promote erosion and deposition of sediment

Morphology – the form and structure of the river channel, e.g. the straightness or depth of the channel

pH - a measure of how acidic a liquid is.  pH 7 is neutral - below this, the lower the pH value, the more acidic it is;  the higher the pH, the more alkaline it is.

Physical modifications – alterations which people have made to the form of the river. They include weirs, and straightening, widening, deepening, canalising or dredging the channel

Phytobenthos - Microscopic plants that live attached to the river bed, or to rocks, stones or large plants within the river channel

Pollution – contaminants which affect the river’s water quality. Examples would be from herbicides, pesticides, organic and artificial fertiliser, sediment, sewage or heavy metals.

Riffle – a stretch of relatively shallow, fast-flowing water

Winterbourne – a stream which flows only after prolonged heavy rainfall leading to high groundwater levels, usually in the winter months