Flood

floodingfloodsflood controlfloodedfloodwaterinundationurban floodinginundatedriver floodspate
A flood is an overflow of water that submerges land that is usually dry.wikipedia
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River

riverineriparianleft bank
Flooding may occur as an overflow of water from water bodies, such as a river, lake, or ocean, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries, or it may occur due to an accumulation of rainwater on saturated ground in an areal flood. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the world's largest rivers.
In larger rivers there is often also a wider floodplain shaped by flood-waters over-topping the channel.

Floodplain

flood plainfloodplainsflood plains
Surface soil can become saturated, which effectively stops infiltration, where the water table is shallow, such as a floodplain, or from intense rain from one or a series of storms.
A floodplain or flood plain is an area of land adjacent to a stream or river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.

Surface runoff

runoffagricultural runoffrun-off
Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more rapidly than it can either infiltrate or run off.
In addition to causing water erosion and pollution, surface runoff in urban areas is a primary cause of urban flooding, which can result in property damage, damp and mold in basements, and street flooding.

Flash flood

flash floodingflash floodsflash-flood
Some floods develop slowly, while others can develop in just a few minutes and without visible signs of rain.
A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions.

Stormwater

storm waterstormwater managementcontrols
Aside from potential overflow of rivers and lakes, snowmelt, stormwater or water released from damaged water mains may accumulate on property and in public rights-of-way, seep through building walls and floors, or backup into buildings through sewer pipes, toilets and sinks.
In developed environments, unmanaged stormwater can create two major issues: one related to the volume and timing of runoff (flooding) and the other related to potential contaminants the water is carrying (water pollution).

New Orleans

New Orleans, LouisianaNew Orleans, LAOrleans Parish
Some recent catastrophes include the inundations of Nîmes (France) in 1998 and Vaison-la-Romaine (France) in 1992, the flooding of New Orleans (USA) in 2005, and the flooding in Rockhampton, Bundaberg, Brisbane during the 2010–2011 summer in Queensland (Australia).
The city's location and flat elevation have historically made it very vulnerable to flooding.

Snowmelt

snow meltmeltwatermelt snow
Although sometimes triggered by events such as flash flooding or snowmelt, urban flooding is a condition, characterized by its repetitive and systemic impacts on communities, that can happen regardless of whether or not affected communities are located within designated floodplains or near any body of water.
Rapid snowmelt can cause flooding.

2010–11 Queensland floods

2010–2011 Queensland floodsJanuary 2011 Brisbane floodsQueensland floods
Recent field measurements during the 2010–11 Queensland floods showed that any criterion solely based upon the flow velocity, water depth or specific momentum cannot account for the hazards caused by velocity and water depth fluctuations.
A series of floods hit Queensland, Australia, beginning in November 2010.

100-year flood

100 year flood100-year500-year flood
Coincident events may cause extensive flooding to be more frequent than anticipated from simplistic statistical prediction models considering only precipitation runoff flowing within unobstructed drainage channels.
A one-hundred-year flood is a flood event that has a 1 in 100 chance (1% probability) of being equaled or exceeded in any given year.

Landslide

landslideslandslipdebris avalanche
Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, or beaver dams.
The resulting slurry of rock and mud may pick up trees, houses and cars, thus blocking bridges and tributaries causing flooding along its path.

Brisbane

Brisbane, QueenslandBrisbane, AustraliaBrisbane, Queensland, Australia
Some recent catastrophes include the inundations of Nîmes (France) in 1998 and Vaison-la-Romaine (France) in 1992, the flooding of New Orleans (USA) in 2005, and the flooding in Rockhampton, Bundaberg, Brisbane during the 2010–2011 summer in Queensland (Australia).
Many suburban creeks criss-cross the city, increasing the risk of flooding.

Stream

creekstreamscreeks
Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the world's largest rivers.
Stream crossings are where streams are crossed by roads, pipelines, railways, or any other thing which might restrict the flow of the steam in ordinary or flood conditions.

Soil

soilsdirtsoil moisture
Surface soil can become saturated, which effectively stops infiltration, where the water table is shallow, such as a floodplain, or from intense rain from one or a series of storms.
Flooding temporarily increases soil permeability in river beds, helping to recharge aquifers.

Dam

earthfilldamsconcrete-face rock-fill dam
The cause may be localized convective precipitation (intense thunderstorms) or sudden release from an upstream impoundment created behind a dam, landslide, or glacier.
Since the fear of flood is a strong motivator in many regions, gravity dams are being built in some instances where an arch dam would have been more economical.

National Flood Insurance Program

Biggert–Waters Flood Insurance Reform Act of 2012NFIPCommunity Rating System
In the United States, insurance is available against flood damage to both homes and businesses.
The program enables property owners in participating communities to purchase insurance protection, administered by the government, against losses from flooding, and requires flood insurance for all loans or lines of credit that are secured by existing buildings, manufactured homes, or buildings under construction, that are located in the Special Flood Hazard Area in a community that participates in the NFIP.

Indoor mold

Mold growth, assessment, and remediationmoldmold remediation
Urban flooding can cause chronically wet houses, leading to the growth of indoor mold and resulting in adverse health effects, particularly respiratory symptoms.
Flooding, leaky roofs, building-maintenance or indoor-plumbing problems can lead to interior mold growth.

Hydrograph

unit hydrographfalling limbhydrographical patterns
As a result, the rising limb of the hydrograph becomes ever quicker as the flood moves downstream, until the flow rate is so great that the depletion by wetting soil becomes insignificant.

Coastal management

coastal defencecoastal protectioncoastal defences
Coastal flooding has been addressed in portions of Europe and the Americas with coastal defenses, such as sea walls, beach nourishment, and barrier islands.
Coastal management is defence against flooding and erosion, and techniques that stop erosion to claim lands.

Lahar

laharsmudflowsvolcanic mudflows
Examples include outburst floods and lahars.

Tropical cyclone

hurricanetropical stormhurricanes
The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones.
Tropical cyclones out at sea cause large waves, heavy rain, flood and high winds, disrupting international shipping and, at times, causing shipwrecks.

Ice jam

ice damice jamsice
Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, or beaver dams.
Where floods threaten human habitation, the blockage may be artificially cleared.

Weir

weirslowhead damlow head dam
Defenses such as detention basins, levees, bunds, reservoirs, and weirs are used to prevent waterways from overflowing their banks.
Weirs are commonly used to prevent flooding, measure water discharge, and help render rivers more navigable by boat.

Wetland

wetlandscoastal wetlandwetland habitat
Another strategy is to reduce impervious surfaces in streets, parking lots and buildings through natural drainage channels, porous paving, and wetlands (collectively known as green infrastructure or sustainable urban drainage systems (SUDS)).
A wetland is a distinct ecosystem that is flooded by water, either permanently or seasonally, where oxygen-free processes prevail.

Hydrology

hydrologicalhydrologisthydrologic
Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health.

Monsoon

southwest monsoonmonsoonsnortheast monsoon
The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones.
Bangladesh and certain regions of India like Assam and West Bengal, also frequently experience heavy floods during this season.