Highly localized events of short duration with a very high peak &
usually have less than six hours between rainfall occurrence & peak flood.
Situation worsens in presence of choked drainage lines or encroachments
obstructing the natural flow of water.
Have a different character than river floods due to short time scales &
occurrence in small spatial scales.
Urban areas are more likely to experience this due to the wide presence
of hard surfaces, unable to soak rainwater, as it would do in rural areas.
CONCERNS
Among the world's deadliest natural disasters with more than 5,000 lives
lost annually.
Have highest mortality rate among different classes of flooding (riverine,
coastal, etc).
Short time scales & occurrences in small spatial scales makes
forecasting difficult.
RELATED INITIATIVES & SUGGESTIONS
Flash Flood Guidance Services: Designed by India Meteorological
Department for real-time warnings & support in advance at watershed level
for flash flood-prone South Asian countries.
South Asian Flash Flood Guidance System: Launched by India
Meteorological Department, with an aim to help disaster management teams in
making timely evacuation plans in advance.
Nations need to improve weather observational networks to provide more
timely data on warnings.
