Predicting and managing floods Flashcards
Recurrence intervals refer to…
regularity of a flood of a given size.
Smaller floods are expected…
to occur regularly.
Larger floods occur less…
often.
A 100-year flood is expected to occur…
on average 1 in 100 years.
Larger floods are less common but…
more damaging compared to smaller ones.
UN made recommendations about needs to…
improve flood prediction and warning.
Examples of UN recommendations:
- improved rainfall and snow estimates
- better gauging of rivers, a collection of meteorological information
- mapping of channels
- better sharing of information
- technology should be shared among all agencies
Natural causes affecting the shape of storm hydrograph:
- a shape of the drainage basin
- gradient
- stream density
Flash floods are…
the result of intense rainfall on steep slopes. Happens in small basins, especially, semi-arid areas.
In HICs the number of deaths from floods…
is declining while the economic cost is increasing.
A flood is…
a high flow of water that overtops the bank of a river.
Most of the floods are associated with…
depressions, long lasting and cover a wide area.
In urban areas, smooth surfaces with…
a dense network of drains and underground sewers increase drainage density.
Whether satellites provide…
flood warning less than 6 hours before the flood. Which is a quite short time.
United Nations Environment programme published…
Early Warning and Assesment
