floods part 4 Flashcards
Why do cities use a range of mitigation measures?
Cities use a range of flood mitigation measures to:
● Reduce the impact of floods
● Prevent floods from occurring
How can cities be successful in reducing flood risks?
To be successful in reducing flood risk, a city needs to:
● Consider its unique characteristics
● Adopt an integrated flood management approach that involves a
combination of suitable mitigation measures
What is REGULATION?
- Regulation
● Regulation refers to a rule or a law which is enforced by an authority and
which states how something should be done.
What are the two examples of regulations?
Zoning and Elevated properties.
Elaborate on zoning.
● Zoning is a way in which the government plans the physical development of
the land and its uses.
● Zoning laws often specify the areas for specific developments
○ Residential
○ Industrial
○ Commercial
○ Recreational
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● Flood-prone areas are often zoned as low-value developments (e.g. parks
and fields for recreational activities)
● A low-value development usually does not cost much to develop and has
activities that bring in less income
What are the advantages of zoning?
● Advantages:
○ Creates green spaces such as parks and fields, which help to reduce
the impact of flood damage.
What are the disadvantages of zoning?
● Disadvantages:
○ May limit the development of available land because only certain land uses are permitted.
○ Difficult to carry out because of competing land uses.
○ People may also not abide by the recommended land use.
Elaborate on elevated properties.
● Another measure used to reduce the impact of floods is to elevate or raise properties to a certain height
● In Singapore, the minimum ground level for a development is known as the minimum platform level (MPL)
● The minimum platform level is the minimum ground level for development.
● An example of how a development can meet MPL requirement is by building
a slope or a series of steps.
What is INVESTMENT IN INFRASTRUCTURE?
● To reduce the impacts of floods, cities can invest in infrastructure
○ Cities can build new infrastructure
○ Cities can maintain existing infrastructure to make sure they are in working condition
● Example: The lack of maintenance of levees was partly responsible for the
devastating floods in New Orleans in 2005
What are the examples of investment in infrastructure?
Levees and floodwalls, channel improvement.
Elaborate on Levees and floodwalls.
● Levees and floodwalls are barriers against floods
● They protect development against floodwater
● They are built higher than floodplains and rivers so that they can help keep out floodwater
● Levees are raised river banks which can be natural or man-made
● Floodwalls are man-made structures and made of concrete
What are the advantages of levees and floodwalls?
● Advantages:
○ Cheaper to build levees and floodwalls to mitigate and prevent floods as compared to raising the height of the surrounding land.
What are the disadvantages of levees and floodwalls?
● Disadvantages:
○ Regular maintenance is required to ensure that levees and floodwalls
are strong enough to hold back floodwater
○ Levees and floodwalls are designed to hold back floodwater up to a
certain level. They are unable to prevent floods beyond that level.
Elaborate on Channel improvement.
● Channel improvement refers to changes made to the river channel or canal
to increase its capacity to hold water or to enable the water to flow quickly.
● Channel improvement can be done many ways to help prevent water in river
channels and canals from overflowing
○ River channels and canals can be widened and deepened so that they
can carry away more storm water
○ River channels and canals can also be straightened so that water can
be carried away quickly
● Example: In Singapore, a section of the Bukit Timah Canal was widened and
deepened to increase the channel capacity
What are the advantages of channel improvement?
● Advantages:
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○ Makes it possible for moderate-value and high-value developments
take place on the land next to river channels and canals.
