• UNDRR
  • DesInventar Sendai
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Flood

Water that overflows river-bed levels ("riverine flood") and runs slowly on small areas or vast regions in usually long duration periods (one or more days).

Urban Flood

Storm water that gets collected in city or urban areas after heavy rains due to blocking or under capacity of storm water drains. It may also be a riverine flood occurring specifically over an urban area.

Flash-flood

Violent water flow in a watershed, overflowing or as torrent; also known as Torrential freshet. Flash-floods usually carry tree trunks and/or abundant fine to bulky sediment. They can be caused by rain, dam bursting or abundant landslides on a watershed or basin.

Surge/Coastal flood

Also known as Tidal Wave. Flood caused by great sea waves breaking on the littoral. Includes reports of incidents caused by tidal waves, high tides, gales, storms -other than tsunami or seaquake- usually by coincidence of wind directions and high tide periods, or by rise of average sea level during the phenomenon “El Niño” or due to Climate Change.

Landslide

All mass movements other than surface erosion of a hillside. This event includes terms such as precipitation of earth, settling, horizontal land thrust, rock falls, (slow or quick) detachment of soil masses or rocks on watersheds or hillsides.

Alluvion

Torrential water flows dragging large amounts of solid material (pebbles, stones, and rock blocks) common in dry regions river beds which are produced by heavy rain. Equivalent to the term “huaico” used in Peru.

Avalanche

Swift sliding of loosened ice and/or snow masses.