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Flooding - Coggle Diagram
Flooding
Mitigations:
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Channeling: straightening, deepening, widening, clearing or lining existing streams
often causes environmental issues
bottleneck flows
Types
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Coastal flood: or the inundation of land areas along the coast, is caused by higher than average high tide and worsened by heavy rainfall and onshore wind
Storm surge: is an abnormal rise in water level in coastal areas, over and above the regular astronomical tide, caused by forces generated from a severe storm's wind, waves, and low atmospheric pressure.
Inland flooding: when moderate precipitation accumulates over several days, intense precipitation falls over a short period, or a river overflows because of an ice or debris jam or dam or levee failure.
Flash flood: caused by heavy or excessive rainfall in a short period of time, generally less than six hours.
Reasons:
Ice jams and snowmelt:
A deep snowpack increases runoff produced by melting snow. Heavy spring rains falling on melting snowpack can produce flash flooding.
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Densely populated: The construction of buildings, highways, driveways, and parking lots increases runoff by reducing the amount of rain absorbed by the ground.
Floods:
occur when water overwhelms a landscape because more water is supplied than can be contained within a stream channel, or than can be removed by infiltration into the ground.
Discharge: volume of water moving past a location in a certain amount of time
Q =A*V
A=cross sectional area of channel
V= velocity of water in channel
100-year flood is a flood that has a 1% chance of happening in any given year. The term refers to the recurrence interval of floods, or how often floods of a certain magnitude happen.
Ithat is needed for flood prediction is not the height of a stream, but its discharge