Inundación

Definition

Flood is usually used as a general term to describe the overflow of water from a stream channel into normally dry land in the floodplain (riverine flooding), higher-than–normal levels along the coast and in lakes or reservoirs (coastal flooding) as well as ponding of water at or near the point where the rain fell (flash floods) (IRDR Glossary).

Facts and figures

Floods are the natural hazard with the highest frequency and the widest geographical distribution worldwide. According to the Organization for Economic Cooperation and Development (OECD)  flooding is one of the most common, widespread and destructive natural perils, affecting approximately 250 million people worldwide and causing more than $40 billion in damage and losses on an annual basis (OECD).

Flooding occurs most commonly from heavy rainfall when natural watercourses lack the capacity to convey excess water. It can also result from other phenomena, particularly in coastal areas, by a storm surge associated with a tropical cyclone, a tsunami or a high tide. Dam failure, triggered by an earthquake, for instance, will lead to flooding of the downstream area, even in dry weather conditions.

Various climatic and non-climatic processes can result in different types of floods: riverine floods, flash floods, urban floods, glacial lake outburst floods and coastal floods.

Flood magnitude depends on precipitation intensity, volume, timing and phase, from the antecedent conditions of rivers and the drainage basins (frozen or not or saturated soil moisture or unsaturated) and status. Climatological parameters that are likely to be affected by climate change are precipitation, windstorms, storm surges and sea-level rise (UNDRR).

When floodwaters recede, affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials such as sharp debris, pesticides, fuel, and untreated sewage. Potentially dangerous mold blooms can quickly overwhelm water-soaked structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera (UNDRR).

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Related content on the Knowledge Portal

  • Heavy rains in the south-west of Serbia caused floods in many villages and cities on 6-7 November, forcing some 300 families to leave their houses.
     

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18966&record=2&last=6.

    read more
  • 60,000 people were left homeless in Colombo and the suburbs. Some of the roads in the city were up to two metres (six feet) under water as drainage systems were unable to cope with the deluge.

    Source: http://GLIDEnumber.net

    See also: Sri Lanka floods leave 58,000 homeless (20/11/2009, Sydney Morning Herald/AFP)

  • In the Erbil and Dahuk Governorates over 3,000 persons (500 families) across ten locations in the mountainous districts of Mergasur, Rawanduz, Choman, Zhakho, Sumel, Aqra were affected by flash flooding following heavy rains and winds on 1 Nov 2009.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18963.

  • 529 people affected by floods in municipality of Guapi, Cauca.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18961.

  • At least 186 people have been affected by heavy rains in Los Santos Province since late October.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18960.

  • Heavy rains have affected more than 680,000 people in Espirito Santo, southeastern Brazil. 4,500 people have been evacuated and 112,300 houses have suffered damages.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18959.

  • Floods due to heavy rain have killed 91 in the departments of Salvador, La Libertad, Cuscatlán, La Paz, San Vicente.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18958.

     

     

    Available Space-based Information for: El Salvador - Floods and Landslides - 09 Nov 2009

    Status Updated 15/11/2009

     

    UNOOSA/UN-SPIDER:

    Email: un-spider [at] unoosa.org

    Link: http://www.un-spider.org/

     

    ReliefWeb:
    Available maps for Hurricane Ida
    Link:...

    read more
  • Floods caused by heavy rains have claimed 15 lives in Thailand's southernmost provinces of Songkhla, Narathiwat, Pattani and Yala.

    http://www.glidenumber.net/glide/public/search/details.jsp?glide=18957.

  • Hundreds of families have been affected by floods in Encarnacion (Itapua), Ayolas (Misiones), Ciudad del Este (Alto Parana) e Ita Cora (Neembucu).

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18939&record=1&last=4495

    Information on Reliefweb: http://www.reliefweb.int/rw/dbc.nsf/doc108?OpenForm&emid=FL-2009-000226-PRY

    read more
  • On 12 and 14 September 2009, two heavy torrential rains poured down in the capital N?Djamena leading to the flooding of almost half of the town. The stormy rains aggravated the already worse situation that started since the beginning of the rainy season. The most affected areas are Walia, Kamda, Toukra, Habena, Chagoua, and Moursal.The Red Cross of Chad?s urban committee conducted a rapid assessment and estimated that over 545 houses were destroyed.

    Source:  http://glidenumber.net/glide/public/search/details.jsp?glide=18925.

    read more

Term Parents

UN-SPIDER Regional Support Offices with hazard-specific expertise