rivers and drainage basins

precipitation

general term for rain, snow, hail etc.

evaporation

change of state from liquid to gas (water to water vapour)

transpiration

loss of water from a plant through its leaves

evapotranspiration

water transferred to atmosphere by evaporation and transpiration

interception

precipitation stopped by plants before reaching soil

river discharge

amount of water flowing in a river, measured in cumecs

surface water

water on Earth’s surface e.g. lakes

channel storage

amount of water in a river channel at a given time

overland flow

surface water flowing downhill to a river

infiltration

water entering the soil from the surface

groundwater

water stored underground in soil and rock

aquifer

permeable rock layer that stores/transmits groundwater

inputs

water entering a drainage basin

outputs

water leaving a drainage basin

stores

places where water is held for a time

flow/transfer

movement of water between stores

source

start of a river

tributary

small river joining a larger one

confluence

where two rivers meet

mouth

where a river enters a sea or lake

drainage basin

area drained by a river and its tributaries

watershed

edge of a drainage basin on high land

sediment

fine particles carried in a river

waterfall

step in river where hard rock lies over soft rock

meander

bend in a river

flood plain

land that floods beside a river

delta

fan

v

shaped valley

abrasion

wearing away of river bed and banks

load

material carried by a river

traction

large stones rolled along bed

erosion

wearing away of rock

deposition

dropping material when river loses energy

hydraulic action

erosion by force of water

attrition

rocks collide and get smaller and rounder

solution

minerals dissolved in water

saltation

stones bounce along river bed

suspension

fine particles carried in water