Rivers Flashcards
What is a river?
Body of water that flows generally into an ocean or lake
What is the water cycle?
Continuous movement of water between sand, sea + air
What is precipitation?
Any moisture falling to the ground e.g rain, hail, sleet, snow, dew, fog + frost
What is interception?
Water prevented from reaching soil e.g trees
What is surface storage?
Water contained on surface of land e.g rivers, lakes and seas
What is infiltration?
Water soaking into soil from surface
What is percolation?
Downward movement of water from soil into deeper stores e.g groundwater
What is groundwater?
Water stored within rocks below earth’s surface
What is transpiration?
Loss of moisture from vegetation back into atmosphere. (Occurs during photosynthesis)
What is evaporation?
Water movement from land/sea into atmosphere by heat of sun
What is the process of evaporation?
Water heated by sun + turns into water vapour (evaporates)
What is the process of condensation?
As water vapour rises, it cools, forming clouds.
What is the process of precipitation?
Water droplets grow in size until they’re heavy enough to fall back to earth’s surface
What is the process of transpiration?
Trees + other plants release water vapour from their leaves.
What is a drainage basin?
Area of land drained by river + its tributaries.
What is the source?
Starting point of a river
What is the confluence?
Point where 2 rivers meet
What is the tributary?
Stream which flows into larger river
What is the mouth?
End of a river where it meets the sea, ocean or lake
What is a watershed?
Boundary between drainage basins, (often ridge of high land).
Draw a diagram of a drainage basin
See flashcard pg 4
What is surface run-off?
Water travelling quickly over ground towards rivers.
What is throughflow?
Sideways movement of water through soil into river
Names 3 river processes.
Transportation, erosion and deposition.
what is erosion?
The wearing away of landscape by natural forces
name the processes of erosion
hydraulic action, corrosion/abrasion, attrition, solution.
What is hydraulic action?
Sheer force of water pounding against beds + banks. Air pushed into cracks + pieces.
What is corrasion/abrasion?
Particles of rock + sand carried in water (rivers load) which constantly scrape + bang against beds + banks of river, wearing them away like sandpaper.
What is attrition?
Rocks in water bang against one another, wearing each other away, making them smaller, smoother and rounder.
What is solution?
Chemical action of river water. Soluble minerals in rocks are dissolved by acids in the water.
What is transportation?
When river has enough energy to carry sediment along its course.
What are the different types of transportation?
Traction, saltation, suspension and solution.
What is traction?
Heavy rocks + boulders are rolled along river-bed. Occurs in flood, when discharge is highest.
What is saltation?
Small stones + pebbles are ‘bounced’ along river bed.
What is suspension?
Very small particles of sand/clay are carried in water.
What is solution?
Material is dissolved in water + carried eg limestone is dissolved by acidic rainwater. (Requires little energy).
What is deposition?
Occurs when river loses energy. Process where material being transported by a river is deposited.
What does hydraulic action do to the outside of the river channel?
Deepens it
