Changing landscapes - Rivers Flashcards
What does the bradshaw model show
Changes that occur in a river as it flows from its source to its mouth
Name some physical factors that cause flooding
Prolonged/heavy rainfall, geology and relief
Name some human factors that influence flooding
Building/urbanisation and deforestation
How does geology effect flooding
Impermeable surfaces such as clay and granite do not allow water to go through them leading to greater surface run-off causing more water to reach the channel quickly
How does relief effect flooding
The steeper the slope the more rapid the flow of water into a river channel
How does building/urbanisation effect flooding
Creates impermeable surfaces increasing surface run-off therefore water reaching the channel faster and in higher volume
How does deforestation effect flooding
Vegetation (trees) intercept rainfall slowing its movement and some of the water is stored before evaporating back into the atmosphere. Trees also absorb water from the soil allowing more water to be able to go into the soil. When vegetation is removed surface run-off is increased
Define watershed
Area of high land forming the edge of a river basin
Define source
Where a river begins
Define mouth
Where a river meets the sea
Define confluence
The point at which two rivers meet
Define tributary
Small river or stream that joins a larger river
Define channel
Where the river flows
State 4 factors that lead to deposition in a river
- Shallow water
- At the end of the rivers journey
- When volume of water decreases
- When a river slows down.
Name two processes of mass movement
Landslides and soil creep
