Rivers And Managment Flashcards
What is precipitation?
Precipitation refers to any form of water, liquid or solid, that falls from the atmosphere and reaches the ground.
What is interception?
Interception is when vegetation stops precipitation from falling directly onto the surface.
What is transpiration?
Transpiration is the moisture lost to the atmosphere through the leaves of plants.
What is infiltration?
Infiltration is the process where water gradually seeps into the soil from the surface.
What is run-off?
Run-off is when water runs across the surface.
What is through flow?
Through flow is when water passes through the soil.
What is discharge?
Discharge is the volume of water flowing through a river channel measured in cumecs.
List three types of mass movement.
Mudflow, rockfall, landslide.
Name the four types of erosion.
Attrition, abrasion, hydraulic action, solution.
What is suspension?
Suspension is when lighter sediment is suspended (carried) within the water.
What is dissolved load?
Dissolved load is made up of solutes derived from chemical weathering of bedrock and soil.
What is saltation?
Saltation is the bouncing of grains as they are picked up, carried along, and dropped repeatedly by flowing water.
What is traction?
Traction is the rolling or dragging of large grains along a river bed or shore.
What is deposition?
Deposition is the laying down of sediment carried by flowing water, with the heaviest load deposited first.
What is a long profile of a river?
A long profile of a river shows the changes in elevation from the source to the mouth.
What is a drainage basin?
A drainage basin is an area where any rain falling will flow into another river basin.
How does a V-shaped valley form?
A V-shaped valley forms when rivers flow quickly downhill, eroding the landscape vertically and steepening the valley sides through processes like hydraulic action and freeze-thaw weathering.
How do waterfalls form?
Waterfalls typically form in the upper stages of a river where hard rock overlies softer rock. The soft rock is undercut by erosional processes such as hydraulic action. Hard rock overhang collapses, creating a plunge pool where water and debris swirl around, further eroding the soft rock and creating an overhang.
What features are found in a meander?
Features of a meander include a river cliff, slip-off slope, lateral erosion on the outside bend, and deposition on the inside bend.
How does an ox-bow lake form?
An ox-bow lake forms when a meander undergoes lateral erosion on the outside bend, causing the neck of the meander to narrow. Eventually, the river cuts through the neck, creating a low energy environment that leads to deposition and cuts off the meander.
What are 4 features of the lower course of a river?
Flat gradient, wide valley, wide/deep channel, small load.
How are levees formed?
Levees are formed by repeated flooding of the river. During floods, water and load leave the channel, and due to friction, the largest material is deposited close to the banks, building up over time.
What factors increase flooding?
Human factors: urbanisation, storm drains into rivers, deforestation, high rates of abstraction, drought, farming, building on flood plains. Physical factors: impermeable rock, steep slopes, heavy rainfall, permeable soil, high temperatures, saturated soil, little vegetation, snowmelt.
What were 6 effects of the Boscastle flooding in August 2004?
100 residents airlifted, 115 cars swept away, 200mm rainfall in 8 hours, no deaths, 1 injured, trees uprooted, bridges washed away.
