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

  • 187 homes destroyed in Moa village in southeast region of Zinder; government and MSF distributing relief supplies

    Source : Glide number

  • Torrential rain and floods have left almost 11,000 people homeless in Bangui since mid-June. Half of the eight districts in the capital have been affected by the floods. Many people have been hurt.

    Source : Glide number

     

    Ressources from OCHA/Reliefweb, click here

  • Benin declared state of emergency and called for international humanitarian aid after 2,000 families been displaced by flooding caused by heavy rains,

    Sources : Glide number

    From Alertnet : Benin declares state of emergency over floods

    Ressources from OCHA/Reliefweb, click here

     

  • Heavy rains triggering floods and landslides in mountainous northern regions of Vietnam have killed at least 15 people, destroyed houses and damaged roads.

    Source : Glide number

     

    Ressources from OCH/REliefweb, click here

  • Torrential rains triggered landslides and flash floods killing six people and stranding half a million in their homes.

    Sources : Glide number

     

    Ressources from OCHA/REliefweb, click here

    Ressources from ADRC, click here

  • Over 300,000 people have been hit by flood in the northeastern Indian state of Assam after incessant rains ,reported the semi-official Press Trust of India.

    Source : Glide number

     

    Ressources from OCHA/Reliefweb, click here

  • At least 10 people died in flooding in the eastern Czech Republic, and rescuers evacuated hundreds of people from wrecked houses and buildings threatened by high water.

    Source : Glide number

     

    Ressources from OCHA/Reliefweb, click here

  • In June 2009, the central provinces of Botswana were affected by very heavy rains, which flooded eight districts.

    Source : Glide number

     

    Ressources from OCHA/Reliefweb, click here

  • Due to heavy rains during the last days, floods have affected 10,818 people in the Department of Escuintla and 183 people have been evacuated.

    Sources : Glide number

     

    Ressources from OCHA/Reliefweb, click here

  • Since the flooding season began, floods in 16 provinces in southern China had left 41 people dead

    Source : Glide number

     

    Ressources from OCHA/Reliefweb, click here

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