The Processes Of The Water Cycle 1C Flashcards
Cryopheric processes ( water as ice)
Accumulation = inputs to the glacial system ( precipitation such as snowfall,rain,avalanches)
Ablation = output from a glacial system ( meltwater )
Sublimation = ice changing directly into water vapour
Groundwater flow
Downward and lateral movement of water in saturated rock
Slow movement
Throughflow
Lateral movement of water down a slope to a river channel
Slower than overland flow but rate is increased by root systems of vegetation
Percolation
Downward movement of water into underground stores. Eg. Rocks
Infiltration
Water soaks in to the soil
Infiltration rate = speed it occurs
Rate is affected by the texture and structure of the organic content with the soil
Eg. In a storm the rate normally declines in the early part
Surface run-off ( overland flow)
Rainfall runs over the surface of the ground
Soil is saturated
Rainfall exceeds soil infiltration capacity
Surface run-off (saturated overland flow)
Soil is saturated
Precipitation
Fall as rain,hail,sleet or snow
Duration impacts processes within the system
Causes of precipitation
Condensation is a direct cause of precipitation
This can occur through air temperature beings reduced to dew point
Adiabatic cooling = as air rises there is no addition of heat
These produce different type of rainfall
Orographic rainfall = Air is forced to rise over hills and mountains
Frontal rainfall = air of different densities and masses. Warm air rises over cool sinking air
Conventional rainfall = warm air rising from hot surfaces on a sunny day.
Condensation
Water vapour becomes liquid
Air cools and it is not able to hold as much water vapour = dew point
When the cooling process occurs, water molecules condense onto nuclei forming droplets or frost. Eg, dust or smoke or surfaces such as grass
Condensation ( cloud formation)
Clouds = visible masses of water droplets/ice crystals
They form when:
Saturated air ( cooled below the dew point or evaporation has meant that air has reached maximum water -holding capacity.
Condensation nuclei is present
Condensation
More moisture in cooling air = more condensation and cloud formation
Transpiration
Liquid becomes gas
Water is lost from plants through the stoma (pores)
Affected by temperature, wind,humidity and sunlight
Thermal energy is required either through water movement or solar radiation
Air cannot be saturated as it need to absorb the water vapour
Evaporation
Liquid to gas
Heat energy required either through the movement of water or solar radiation
Air can’t be saturated as it needs to hold the water vapour
Affected by temperature,wind,humidity and sunlight
Base flow
Inputs to streams and rivers from natural reservoirs and soils eg,
