The Water Cycle Flashcards
Precipitation
The input into a drainage basin system
Interception
The storage of water when it lands on vegetation (or buildings) before it reachers the soil
Surface storages
The storage of water on the surface including puddles, ponds and lakes
Soil moisture
The storage of water in soil. Water is held in the small gaps between soil particles
Groundwater storage
The storage of water in the ground rocks of permeable rock, held in the cracks
Channel storage
The storage of water in the river channel. As water is being transported to the sea it is a store of water
Vegetation storage
The storage of water in the vegetation. Plants and trees take up water through their roots and water is stored here.
Surface runoff / overland flow
The horizontal flow of water over the surface of the land either in little channels or over the whole surface - usually a quick flow.
Stem flow
The downwards flow of water moving from interception storage to the surface
Through fall
The downwards movement of water as it drips from one leaf to another
Throughflow
The horizontal flow of water moving through soil (between particles) towards the river
Interflow
The horizontal movement of water through rock above the water table. (Below is groundwater flow)
Infiltration
The downwards movement of water from the surface into the soil
Percolation
The downwards movement of water from the soil to the permeable ground rock
Groundwater flow
The horizontal movement of water through the rocks below the water table
Baseflow
Groundwater flow that feeds into rivers
Channel flow
The movement of water in the river channel moving towards the sea
Evaporation
- The output of water when it is turned from a liquid to a gas.
- Affected by: temperature, wind, humidity and water availability
Transpiration
The output of water where moisture is taken into plants through their roots, moved into the leaves by capillary action and then evaporates from the leaves into a gas
Evapotranspiration
The combined output of water from evaporation and transpiration.
Condensation
Transfer of water from a gaseous state to a liquid state e.g cloud formation
Condensation nuclei
Microscopic particles on which water vapour condenses to for, cloud droplets e.g. dust or smoke
Dew point
The temperature at which water vapour in the air becomes saturated and condensation begins
Sublimation
Transfer from a solid state (ice) to a gaseous state (water vapour)
Deposition
Transfer from a gaseous state (water vapour) to a solid state (ice)
Latent heat
The heat required to convert a solid to a liquid or gas/ liquid to gas, without change of temperature
Discharge
The output of water from a river channel out to sea
Aquifer
A vast underground reservoir most commonly formed in rocks such as chalk and sandstone
Impermeable surface
Does not allow water to pass through
Permeable surface
Allows water to pass through
Urbanisation
The increasing proportion of people living in towns at cities, opposed to the countryside - leading to the replacement of vegetated ground with impermeable concrete-tarmac
Deforestation
The removal of trees, leading to surface runoff, soil erosion and reducing soil water stores
Drainage basin
The area of land that is drained by a river and its tributaries
Source
The point where the river begins (shallow and narrow- discharge is low)
Mouth
The point where the river meets the sea. The river is wide and deep here, and discharge is high.
Watershed
The edge of a drainage basin
Tributary
Smaller rivers that feed into the main channel
Confluence
The point where two rivers meet
Flood (storm) hydrograph
A graph showing the discharge of a river following a particular storm event
Lag time
Time between peak rainfall and peak discharge. Longer lag time = less likely to cause a flood
River regime
The pattern of discharge over the course of a year. Affected by geology, vegetation, urbanisation, size/shape of drainage basin, rainfall intensity etc.
Soil moisture (water)budget
Describes the changes in the soil water store during the course of a year. Determined by precipitation and evapotranspiration.
Soil moisture utilisation
The extraction of soil moisture by plants for their needs; efficiency of withdrawal decreases as the soil-moisture storage is reduced.
Soil moisture deficit
The point at which soil moisture falls below field capacity - caused by a lack of precipitation and large amounts of evapotranspiration
Soil moisture recharge
Following soil moisture deficit, precipitation is greater than potential evapotranspiration moisture will be added to the soil.
Field capacity
The point at which soil becomes saturated
Soil moisture surplus
The period when soil is saturated and water cannot enter, and so flows over the surface – caused by low levels of evapotranspiration and high levels of precipitation
Soil porosity
Pores or spaces in the soil. The greater pores or spaces, the greater the water holding ability.
Water balance
An equation used to express the relationship between the main water stores – the lithosphere, the hydrosphere, the cryosphere and the atmosphere
Hill slope system
The way in which water moves down a typical hillslope towards a river, involving stores and transfers
Irrigation
The supply of water to the land by means of channels, streams and sprinklers in order to permit the growth of crops
Water table
The upper level of saturated rock
Water abstraction
The extraction of water from rivers or groundwater aquifers
Saltwater intrusion
The movement of saltwater into an aquifer, which may cause contamination. Often caused by over abstraction of groundwater from an aquifer.
Relief/orographic rainfall
Rainfall formed due to warm moist air being forced to rise by the relief of the land. Once risen, the air cools and condenses forming rain.
Frontal rainfall
Rainfall formed when warm air meets cold air. Warm air is less dense and therefore rises above the cold air, cooling, condensing and forming rain.
Conventional rainfall
Rainfall formed when heat from the sun heats the ground. The warm ground heats the air above causing it to rise, cool, condense and form rain.
Ablation
Outputs from a glacial system due to melting (size of glacier decreases)
Accumulation
Inputs to a glacial system due to snowfall (builds a glacier)