Rivers Flashcards
What are the components of the water cycle and their definitions?
Evaporation: Water changes from a liquid to a vapour
Condensation: Cooling vapour turns into a liquid
Precipitation: The name given to water that falls on the earths surface
Transpiration:Plants and teas release water vapour into the atmosphere from their leaves
Surface runoff:Movement of water over the land
Groundwater:Water that has sunk into the soil
Infiltration:Water seeps into the ground
Percolation:Water flows vertically through the soil and rocks
What are the features of the drainage basin and their meaning?
Source:The area were a river begins
Mouth:The place that the river ends usually a sea or lake
Tributary:A smaller river that joins a larger river
Confluence:The point were two rivers join
Watershed:The boundary between two drainage basins marked by a ridge of high land
Drainage basin:The are which is drained by a river and its tributaries
What are the 4 processes of erosion?
Hydraulic action:The force of water against the bed and banks
Solution:The acids in the water slowly dissolve the bed and banks.
Attrition:Material carried by the river bump into each other and so are smoothed and broke down into smaller particles.
Abrasion:The bed and banks are worn down by the river load
What are the 4 processes of transportation
Traction:Boulders and pebbles are rolled along the river bed.
Saltation:Sand sized particles are bounced along the river bed.
Suspension:Fine clay and sand particles are carried along in the water.
Solution:Some minerals dissolve in water.
How is a V shaped valley formed?
The river only has enough energy to erode downwards the valleys sides are slowly broken down through weathering. The material is then transported via gravity and rainfall towards the river channel.
How is a waterfall formed?
Soft rock erodes quicker than hard rock. When the soft rock erodes leaving the hard rock overhanging it eventually collapses. The rock falls into the plunge pool and causes more erosion
How is a gorge formed?
A gorge is formed when a waterfall moves upstream leaving a steep sided gorge
How is a meander formed?
A meander starts as a slight bend. Because water flows faster on the outside of a river than the inside the outside of the bend erodes away. The material is deposited on the inside of the bend creating a bend.
How is an ox-bow lake formed?
An ox-bow lake starts with a meander when the river has enough energy it will flow straight across instead of around the loop the river keeps to its new channel so the loop is left as an ox-bow lake.
How is a floodplain formed?
When a river floods it leaves behind a layer of sediment.
