WATER ON THE LAND Flashcards
What is the river system part of?
The hydrological cycle
What is a drainage basin?
Area of land where rain collects, runs into a river
Often bowl shaped (sides of bowl being valley sides of mountain area)
What is the mouth?
The point where the river flows into the sea
What is the watershed?
Boundary between two drainage basins
What is the confluence ?
The point where two rivers meet
What is a river channel?
The landform which the river flows through.
What is the source?
The start of a river
What is a tributary?
A river that flows into the main channel
What is a long profile?
A line representing the course of a river from its source to its mouth.
Valley features in the upper course?
Highland
V shaped valley
Steep sides
River features in the upper course?
Gradient is steep
river narrow
What are the valley features in the middle course?
Lower land
Steep v shape on sides
Wider valley form
River features in the middle course?
River starts to form meanders
What are the valley features of the lower course?
Flat land
Low lying
River features of lower course?
Wide channel
Oxbow lake
Meander scar
What is vertical erosion?
This deepens the river valley making it v shaped
What is lateral erosion?
This widens the river valley making it v shaped.
What is the hydrological cycle?
A closed system (nothing is created or destroyed)
All water is recycled
What is deposition?
The dropping of eroded material that a river is carrying
What is a flood plain?
A wide flat area of land at either side of the river in its lower course
What do contour lines tell you?
The direction a river flows
What is weathering?
Weathering wears away the valley sides and the stream removes the debris
What is interlocking Spurs?
The river goes around the slopes of the hills called Spurs. They look as if they’re locking together when you look up the valley.
The river channel in the middle course is…
Wider
Deeper
Has a greater volume of water
What is a meander?
A bend in the river course
Steps of meanders…
A bend in river forms meander
Neck of meander gets narrower over time due to erosion on outer bend
Continued erosion means neck gets narrower during flood water travels straight across taking quickest route
River deposits rocks and soil at edges creating oxbow lake
Oxbow lake dries up leaving meander scar
Flood hydrographs…
The bars mean rainfall (mm)
Rising limb shows the rising flood water in the river
Basin lag time means the time difference between the peak of the rainstorm and the peak flow of river
Case studies for water on the land are …
Bangladesh boscastle
Flood management strategies are…
Damns and reservoirs Channel straightening Flood warnings Preparation Flood plain zoning Do nothing
What is hard engineering?
Work against nature
Man made structures
They give immediate results
Expensive
What is soft engineering?
Work with nature
A more sustainable form of flood management
Much cheaper than hard engineering
What are the reasons for an increase in demand of water?
More people
More wealth
Demand for things which require a lot of water
How to meet water demands?
Water meters
Houses designed with better water efficiency
Collect rainwater
Recycle water
How many types of erosion are there?
4
What is abraision?
Eroded rocks picked up by river scrape and rub against channel wearing it away
What is solution?
River water dissolves some type of rock
What is attrition?
Eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges get rounded as they rub together.
What is hydraulic action?
The force of the water breaks rock particles away from the river channel
What is traction?
Large particles like boulders are pushed along the river bed by the force of the water.
What is suspension?
Small particles like silt and clay are carried along by water.
What is saltation?
Pebble-sized particles are bounced along the river bed by the force of the water.
What is solution ( transport ) ?
Soluble materials dissolve in the water and are carried along.
