Chapter 5: Floods, part one, types and causes of floods Flashcards
1
Q
What is a flood?
A
A flood is an overflow of large amounts of water onto land that is normally dry.
2
Q
What are the 3 types of floods?
A
- coastal floods
- river floods
- flash floods
3
Q
What is a coastal flood?
A
Coastal floods are floods that are caused by intense storms. They occur in areas near the coast that are low lying.
4
Q
What is a river flood?
A
- occur when water levels rise and overflow its banks
- occur on the floodplain which consists of the river and the low-lying land on either side of it
- Causes my include snowmelt, heavy rainfall or dam failure
5
Q
What is a flash flood?
A
- quick rise in water level
- takes place suddenly and lasts for short periods of time
- caused by various factors like heavy rainfall and/or coastal and river floods
6
Q
What are some causes of floods?
A
- intense rainfall
- snowmelt
- storm surge
- failure of man-made structures
7
Q
What is intense rainfall?
A
It is rainfall with high rainfall intensity (the rate at which rain falls), duration of rain fall and rain fall frequency (the chance of rain.
8
Q
What is snowmelt?
A
- caused by surface runoff from melting snow
- fills rivers causing rivers to overflow due to access water.
9
Q
What are storm surges?
A
- sudden rise in sea level when water is piled up against a coastline beyond normal high-tide conditions
- strong winds push water toward the coast creating large waves causing a storm surge
10
Q
What is the failure of man-made structure?
A
- the failure of dams, levees and floodwalls will result in floods
- dams store and retain water. When i dam fails flooding can result.
- Levees are raised river banks which can be natural or man-made. They act as flood barriers, but will cause flooding when they fail
- Floodwalls are man-made structures made of concrete which act as barriers. They can cause flooding when they fail.
