2.2 Rivers Flashcards
Tributary
A stream or river which joins a larger river
Drainage basin
The area of land drained by a river system
Watershed
A ridge or other line of separation between two river systems
Confluence
A point at which two rivers meet
Interception
The precipitation that is collected and stored by vegetation
Infiltration
Movement of water into the soil
Rate at which water enters the soil, depends on rainfall, permeability of souk and extent which already saturated
Throughflow
Downslope movement of water in subsoil
Evaporation
The process in which a liquid turns to a vapour
Overland flow
Overland movement of water after rainfall
Fastest way in which water reaches a river. Amount of overland runoff increases with heavy and prolonged rainfall, steep gradients, lack of vegetation cover and saturated / frozen soil
Abrasion
Wearing away of the bed and bank by the load carried by a river
Attrition
The wearing away of the load carried by a river
Created smaller, rounded particles
Hydraulic action
Force of air and water on the sides of rivers and in cracks
Groundwater flow
Movement of water from land to river through rock
Slowest form of water movement
Suspension
Small particles are held up by turbulent flow in the river
Saltation
The removal of chemical jobs esp. calcium which cause rocks to dissolve
Chemical load is carried dissolved in the water
Traction
Heaviest material is dragged or rolled along the bed of the river
Main types of transport
Suspension Saltation Solution Traction (Flotation)
Deposition
Occurs due to a decline in energy or velocity
Landforms caused by erosion
Waterfalls
Gorges
Potholes
Landforms caused by erosion and deposition
Meanders
Oxbow lakes
Landforms caused by deposition
Levees and floodplain
EXAM QUESTION
Briefly explain how waterfalls and gorges are formed (4 marks)
Draw annotated diagram to show formation of oxbow lake (4 marks)
Long and cross section profiles of river diagram
