Rivers and Hydrological Processes Flashcards

Vocabulary flashcards covering key hydrological concepts, drainage basin features, river processes, landforms, and flood management.

Hydrological Cycle

A closed system on Earth in which water is constantly recycled through global stores and transfers.

Interception

A store in the hydrological cycle where precipitation is prevented from reaching the ground, usually caught on plant leaves or branches.

Aquifers

Permeable rocks such as limestone and sandstone that are capable of holding water underground.

Evaporation

The transfer process involving the change of water from a liquid into a gas (water vapour) due to solar heat.

Condensation

The process occurring when water vapour cools and changes into liquid water droplets, forming clouds.

Transpiration

The release of water vapour into the atmosphere directly from plant leaves.

Evapotranspiration

The combined transfer of water vapour to the atmosphere from both the Earth's surface and plant transpiration.

Precipitation

The movement of water from the atmosphere to the Earth's surface in the form of hail, sleet, snow, or rain.

Overland Flow

Any flow of water moving across the Earth's land surface.

Infiltration

The downward movement of water from the land surface directly into the soil.

Percolation

The transfer process where water moves further down through soil into rock layers and aquifers.

Through Flow

The movement of water through soil layers between the groundwater store and the land surface.

Groundwater Flow

The slow movement of water through permeable rock layers underground.

Drainage Basin

An open system that drains all surface water landing on the area into a specific river network.

Watershed

The boundary line or elevated land separating adjacent drainage basins.

Source

The origin point furthest from the river mouth where the river starts, such as an upland lake, spring, or glacier.

Confluence

The meeting point where two or more streams or rivers join together.

Tributary

A smaller river or stream that flows into a larger main river channel.

Mouth

The point where a river empties into a sea, ocean, or lake.

Drainage Density

A measure indicating the total number of tributaries within a drainage basin network.

Erosion

The wearing down and removal of rock and soil surfaces by natural forces.

Hydraulic Action

The force of flowing water dislodging and removing material directly from the river bed and banks.

Abrasion

The grinding process where rock fragments carried by a river scrape away at its banks and bed.

Attrition

The collision process where river-carried load materials strike each other, breaking down into smaller, rounder pieces.

Corrosion (Solution)

The chemical process where soluble rocks are dissolved by slightly acidic river water.

Vertical Erosion

Downward erosion dominant in the river's upper course that deepens the river channel and valley.

Lateral Erosion

Sideways erosion dominant in middle and lower river courses that increases valley and channel width.

Traction

A transportation process where larger boulders and heavy load roll along the riverbed.

Saltation

A transportation process where small, bounce-capable sediment particles leap along the riverbed.

Suspension

A transportation process where light sediment particles are supported and carried within moving river water.

Solution (Transportation)

A transportation process where dissolved rock minerals are carried invisibly within the river water.

Deposition

The process occurring when a river loses energy and drops the materials it can no longer carry.

Alluvium

Lighter river sediment including gravel, sand, and silt carried downstream and deposited along floodplains.

Bradshaw Model

A theoretical model illustrating changes in river channel characteristics from source to mouth.

Long Profile

A diagram depicting changes in river gradient along its course from source to mouth.

Waterfall

A sharp drop along a river bed created when hard rock overlies softer rock, leading to severe undercutting.

Interlocking Spurs

Projecting ridges of land in an upper-course V-shaped valley around which a river meanders.

Potholes

Circular depressions in a riverbed formed by abrasive sediment spinning inside hollows.

Thalweg

The path of fastest-flowing water current in a river channel.

Slip-off Slope

A gently sloping feature formed on the inner bend of a meander by continuous sediment deposition.

Oxbow Lake

A curved lake formed when a meander neck is breached during flooding and abandoned due to deposition.

Floodplain

A wide, flat area of low-lying land on either side of a river channel created by repeated flood deposition.

Levees

Natural raised embankments running along river banks, formed by heavy sediment deposition during floods.

Delta

A landform created at a river mouth where flowing water enters a stationary body of water and deposits sediment rapidly.

Flocculation

The clumping together of salt and sediment particles in estuaries, increasing deposition rates.

Lag Time

The delay time measured on a hydrograph between peak rainfall and peak discharge.

Hard Engineering

Flood management using artificial structures or physical engineering to alter river channels.

Soft Engineering

Flood management strategy working with natural processes and environments to reduce flood risk.