Flooding near Key West, Florida, United States from Hurricane Wilma's storm surge in October 2005

A flood is an overflow of an expanse of water that submerges land, a deluge. ^[1] In the sense of "flowing water", the word is applied to the inflow of the tide, as opposed to the outflow or "ebb". Characteristics A tide is a repeated cycle of sea level changes in the following stages Over several hours the water rises or advances up a beach in the flood

It is usually due to the volume of water within a body of water, such as a river or lake, exceeding the total capacity of the body, and as a result some of the water flows or sits outside of the normal perimeter of the body. It can also occur in rivers, when the strength of the river is so high it flows right out of the river channel , usually at corners or meanders. These of course, are not applicable in such instances as sea flooding.

The word comes from the Old English flod, a word common to Teutonic languages, compare German Flut, Dutch vloed from the same root as is seen in flow, float.

The term "The Flood" usually refers to the great Universal Deluge described in Genesis and is treated at Deluge. The story of a Great Flood (also known as the Deluge) sent by a Deity or deities to destroy Civilization as an act of Divine retribution is a

Principal types of flood

Riverine floods

Flooding of a creek due to heavy monsoonal rain and high tide in Darwin, Northern Territory, Australia

• Slow kinds: A large quantity of rainfall or snowmelt navigated to a river at a too rapid speed for the river to cope. The Northern Territory is a federal territory of Australia, occupying much of the center of the mainland continent as well as the central northern regions For a topic outline on this subject see List of basic Australia topics. These floods mainly occur in monsoon areas, where there is high precipitation.
• Fast kinds: flash flood as a result of e. g. an intense thunderstorm.

Estuarine floods

• Commonly caused by a combination of sea tidal surges caused by storm-force winds.

Coastal floods

• Caused by severe sea storms, or as a result of another hazard (e. g. tsunami or hurricane).

Catastrophic floods

• Caused by e. g. dam breakage, or as a result of another hazard (e. g. earthquake or volcanic eruption).

Other

• Flooding can occur if water accumulates across an impermeable surface (e. g. from rainfall) and cannot rapidly dissipate (i. e. gentle orientation or low evaporation).

Typical effects

Primary effects

• Physical damage- Can range anywhere from bridges, cars, buildings, sewer systems, roadways, canals and any other type of structure.
• Casualties- People and livestock die due to drowning. It can also lead to epidemics and diseases.

Secondary effects

• Water supplies- Contamination of water. Clean drinking water becomes scarce.
• Diseases- Unhygienic conditions. Spread of water-borne diseases
• Crops and food supplies- Shortage of food crops can be caused due to loss of entire harvest. Waterborne diseases are caused by Pathogenic Microorganisms which are directly transmitted when contaminated Drinking water is consumed ^[2]

Tertiary/long-term effects

• Economic- Economic hardship, due to: temporary decline in tourism, rebuilding costs, food shortage leading to price increase etc, especially to the poor.

Flood defences, planning, and management

Autumn Mediterranean flooding in Alicante (Spain), 1997. ||-||} Alicante ( Spanish language) or Alacant ( Valencian) is a city in Spain, the capital of the province of Alicante and of the Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula.

In western countries, rivers prone to floods are often carefully managed. Defences such as levees, bunds, reservoirs, and weirs are used to prevent rivers from bursting their banks. Dike (constructionEmbankmentA levee, levée, dike (or dyke) embankment, floodbank or stopbank is a natural or artificial Bunding, also called a bund wall, is the area within a structure designed to prevent Inundation or breaches of various types A reservoir is most broadly a place or hollow vessel where Fluid is kept in Reserve, for later use WEIR (1430 AM) is a Radio station broadcasting a News Talk Information format Coastal flooding has been addressed in Europe with coastal defences, such as sea walls and beach nourishment. In some jurisdictions the terms sea defense and coastal protection are used to mean respectively defence against flooding and erosion A seawall is a form of hard and strong Coastal defence constructed on the inland part of a Coast to reduce the effects of strong Waves.

London is protected from flooding by a huge mechanical barrier across the River Thames, which is raised when the water level reaches a certain point (see Thames Barrier). London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. The Thames ( is a major River flowing through southern England. The Thames Barrier is a flood control structure on the River Thames, constructed between 1974 and 1984 at Woolwich Reach and first used defensively in 1983

Venice has a similar arrangement, although it is already unable to cope with very high tides. Venice ( Italian: Venezia, Venetian: Venesia or Venexia) is a city in Northern Italy, the capital of the The defenses of both London and Venice will be rendered inadequate if sea levels continue to rise.

The largest and most elaborate flood defenses can be found in the Netherlands, where they are referred to as Delta Works with the Oosterschelde dam as its crowning achievement. The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands The Deltaworks are a series of constructions built between 1950 and 1997 in the southwest of The Netherlands to protect a large area of land around the Rhine-Meuse-Scheldt Oosterschelde (Eastern Scheldt is an Estuary in Zeeland, The Netherlands, between Schouwen-Duiveland and Tholen on the north and These works were built in response to the North Sea flood of 1953 of the southwestern part of the Netherlands. The North Sea flood of 1953 and the associated storm combined to create a major Natural disaster which affected the coastlines of the Netherlands and England The Dutch had already built one of the world's largest dams in the north of the country: the Afsluitdijk (closing occurred in 1932). The Afsluitdijk ( English: Closure Dike Frisian: Ofslútdyk is a major dike in the Netherlands, constructed between 1927 and

Flood blocking the road in Jerusalem

Currently the Saint Petersburg Flood Prevention Facility Complex is to be finished by 2008, in Russia, to protect Saint Petersburg from storm surges. Jerusalem (יְרוּשָׁלַיִם, he-Latn Yerushaláyim; Arabic: ar القُدس, ar-Latn al-Quds) is the The Saint Petersburg Flood Prevention Facility Complex (Комплекс защитных сооружений Санкт-Петербурга от наводнений unofficially Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending Saint Petersburg ( tr: Sankt-Peterburg,) is a city and a federal subject of Russia located on the Neva River Storm surge or tidal surge is an offshore rise of water associated with a low pressure weather system typically a Tropical cyclone. It also has a main traffic function, as it completes a ring road around Saint Petersburg. Eleven dams extend for 25. 4 kilometres and stand eight metres above water level.

The New Orleans Metropolitan Area, 35% of which sits below sea level, is protected by hundreds of miles of levees and flood gates. New Orleans&ndashMetairie&ndashKenner is a metropolitan area designated by the US Census encompassing seven parishes in the state of Louisiana, centering on This system failed catastrophically during Hurricane Katrina in the City Proper and in eastern sections of the Metro Area, resulting in the inundation of approximately 50% of the Metropolitan area, ranging from a few inches to twenty feet in coastal communities.

In an act of successful flood prevention, the Federal Government of the United States offered to buy out flood-prone properties in the United States in order to prevent repeated disasters after the 1993 flood across the Midwest. Several communities accepted and the government, in partnership with the state, bought 25,000 properties which they converted into wetlands. These wetlands act as a sponge in storms and in 1995, when the floods returned, the government didn't have to expend resources in those areas. ^[3]

In China, flood diversion areas are rural areas that are deliberately flooded in emergencies in order to protect cities [1]. The Grand Canal of China ( also known as the Beijing-Hangzhou Grand Canal ( is the longest ancient Canal or artificial River in the world

(See Crossing the Lines)

Benefits of flooding

There are many disruptive effects of flooding on human settlements and economic activities. The Crossing the lines project brings the communities of Utrecht (the Netherlands and Mortsel (Belgium and the County of Essex (Great Britain together However, flooding can bring benefits, such as making soil more fertile and providing nutrients in which it is deficient. Periodic flooding was essential to the well-being of ancient communities along the Tigris-Euphrates Rivers, the Nile River, the Indus River, the Ganges and the Yellow River, among others. Mesopotamia (from the Greek meaning "land between the rivers" is an area geographically located between the Tigris and Euphrates rivers largely corresponding The Nile (النيل, Ancient Egyptian iteru or Ḥ'pī, Coptic piaro or phiaro) is a major north-flowing River The Indus River { Sanskrit: सिन्धु Sindhu; Urdu: urd {{Nastaliq سندھ}} Sindh; Sindhi: snd The Ganges (ˈgænʤiːz also Ganga, Devanāgarī: hi गंगा in most Indian languages) is the major river in the Indian subcontinent The Yellow River or Huang He / Hwang Ho ( Hatan Gol Queen river) is the second-longest river in China (after the Yangtze River) and the The viability for hydrological based renewable sources of energy is higher in flood prone regions.

See also

Dozens of villages were inundated when rain pushed the rivers of northwestern Bangladesh over their banks in early October 2005. ( Bengali: বাংলাদেশ inc-Latn Bangladesh) officially The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured the top image of the flooded Ghaghat and Atrai Rivers on October 12, 2005. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Events 539 BC - The army of Cyrus the Great of Persia takes Babylon. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. The deep blue of the rivers is spread across the countryside in the flood image.

• Floods in the United Kingdom
• Floods in the United States
• Floods in Australia
• Flood risk assessment

References

External links

• Integrated Flood Management
• Catastrophic flood database
• Dartmouth Flood Observatory
• Decision tree to choose an uncertainty method for hydrological and hydraulic modelling, Choosing an uncertainty analysis for flood modeling.
• Flood Risk Management Research Consortium
• DeltaWorks.Org Flood protecting dams and barriers project in the Netherlands
• Safecoast Knowledge exchange on coastal flooding and climate change in the North Sea region
• Protecting against the Next Katrina - Scientific American Magazine (October 2005)
• Europe floods 2006
• International teaching module "Integrated Flood Risk Management of Extreme Events" (FLOODmaster)
• Related articles at Appropedia, a wiki for non-Wikipedia (projects & practical "how to") content.
• American Water Resources Association
• Predictions Off for Global Warming Flood Risk - Study.
• Flood Risk Assessment
• Social & Economic Benefits/Costs of Heavy Rain & Flooding from "NOAA Socioeconomics" website initiative