Floods
WHAT ARE THEY?
They are natural occurrences.
THE IMPACTS
Positive Impacts
Negative Impacts
Supports cultivation of rice crops for farmers.
Damage to property.
Loss of lives.
TYPES OF FLOODS
River Floods
Flash Floods
They occur when the volume of water increases beyond the capacity of the channel.
They take place suddenly and lasts for a short period of time.
Water overflows the riverbanks and onto the floodplain.
The raised banks of the river channel are called levees.
A floodplain is the low-lying land on either side of the river channel.
Possible causes are snowmelt, heavy rainfall and dam failure.
They are caused by heavy rainfall.
They are overflows of large amounts of water onto land that i normally dry.
Coastal Floods
They can also be caused by coastal and river floods.
You can recognise a flash flood by its quick rise in water level.
They occur in areas along the coast.
Low-lying coastal areas are especially prone.
They are caused by intense storms such as tropical storms and cyclones.
Tropical cyclones are also known as typhoons or hurricanes.
Strong winds during these storms generate large waves known as storm surges.
Storm surges bring about higher water levels and cause coastal floods.
They can also be caused by tsunamis, which are huge ocean waves typically caused by undersea earthquakes, and can sometimes reach heights of over 30m.