3. Water Cycle Key Terms Flashcards
Evaporation
The change in state of water from a liquid to a gas.
Evapotranspiration
The combined effect of evaporation from vegetation and transpiration.
River Discharge
The volume of water flowing through a river channel; measured at any given point in cubic metres per second (cumecs).
Interception
When vegetation prevents precipitation from reaching the ground.
Soil Water
The amount of water stored in the soil.
Surface Water
The water stored on the surface of the Earth, including streams, rivers, lakes, wetlands, reservoirs, and creeks.
Ground Water
The amount of water stored in the subsurface pore space of soil and rocks.
Channel Storage
The amount of water stored in streams and surface channels
Throughfall
The process which describes how wet leaves shed excess water onto the ground surface
Stemflow
Water running down a plant stem or tree trunk.
[Overland Flow] Surface Runoff
The flow of water that occurs when excess stormwater, meltwater, or other sources flows over the earth’s surface
Slope wash / sheet wash
The transportation of rock and soil down a slope by rain
Rainsplash
The process where soil particles are knocked into the air by raindrop impact
Channel Flow
The flow of water through streams and surface channels
Infiltration
The downward movement of water from the surface into the soil.
Percolation
The downward movement of water from the soil into the rock beneath.
Throughflow
The flow of water downslope within the soil.
Groundwater Flow
The deeper movement of water through underlying permeable rock below the water table.
Base Flow
The stream discharge produced by water seeping from the bedrock.
Water Table
The depth at which all the pores in the rock/soil have been saturated with water
Ground Water
The amount of water located in the subsurface pore space of soil and rock
Recharge
The replenishment, or renewal, of groundwater in aquifers
Springs
Areas where water pressure causes a natural flow of groundwater onto the earth’s surface.
Abrasion
Bits of rock and sand scrape against surfaces, grinding them down in a sandpaper-like effect
Corrasion
A type of abrasion
A type of abrasion where bedload in the river wears against the bed and banks
Attrition
Rocks / Pieces of material crash into each other as they are carried downstream, causing them to break and become smoother
Solution
The dissolution of fine sediment by weak acids contained in the river over time, especially chalk and limestone.
Cavitation
A type of hydraulic action
A process of hydraulic action where air bubbles trapped in the water get compressed into small spaces like cracks in the river’s banks.
These bubbles eventually implode creating a small shockwave that weakens the rocks.
Hydraulic Action
A process where the water smashes against the river banks, forcing air to become trapped in the cracks of the river bank and bed and the rock to break apart
Traction
A process where large material is dragged or rolled along the river bed.
Saltation
A process where material bounces along the river bed as it is carried by the current.
Suspension
A process where fine material is carried / suspended in the river’s current.
What is saturated overland flow?
Saturated overland flow is where surface runoff occurs as all the pores of the soil are saturated.
This is better than Hortonian flow for reduced flooding - the soil has partly done its job!
What is Hortonian flow?
Hortonian flow is where surface runoff occurs as the infiltration capacity of the soil is too low to account for the rainfall intensity.
Water is absorbed slower than rainfall, usually because the material is not permeable.
