50 Fun Facts About Floods

Flash floods have a gap between rainfall and flooding of fewer than how many hours?

Urban flooding, on paved ground that cannot absorb water, is often of this type.

Which adjective describes flooding from rain pooling on saturated or frozen ground, not a river overflowing?

It happens in flat places like floodplains and endorheic basins where water arrives faster than it can soak in or run off.

A '100-year flood' is one with what probability of occurring in any given year?

The name is misleading: many places can each have their own 100-year flood in the same year.

Deliberate agricultural flooding is used to prepare fields for growing which semi-aquatic crop?

Paddy fields are flooded on purpose; land is also flooded intentionally for military or river-management reasons.

Which of these is a waterborne disease whose spread increases after floods?

Hepatitis A and E and diarrhoeal diseases are others; malaria and dengue rise too, but via mosquitoes breeding in standing water.

Periodic flooding sustained ancient peoples along the Tigris, Euphrates, Indus and which other river?

The annual inundation deposited fertile silt on the fields; the Ganges and Yellow River civilisations depended on the same cycle.

'Overland flooding' in the flat Red River Valley affects Minnesota, North Dakota and which Canadian province?

The Red River of the North drains north into Lake Winnipeg, so spring melt in the south hits ice still frozen downstream.

The 1931 floods often ranked the deadliest natural disaster in history struck which country?

The Yangtze and Huai rivers burst after drought, snowmelt and rain; estimates of the dead range from 140,000 drowned to 2 to 4 million including famine and disease.

The 1931 China floods hit which two major cities on the Yangtze?

The government estimated 25 million people were affected; four Yangtze weather stations recorded over 600 mm of rain in a month.

Which waterway, nicknamed 'China's Sorrow', flooded in 1887, killing at least 930,000?

The river, nicknamed 'China's Sorrow', overwhelmed its dikes around 28 September after days of heavy rain.

The Great Mississippi Flood of 1927 inundated roughly how many square miles?

Water stood up to 30 feet deep for months, and 94% of the 630,000 people affected lived in Arkansas, Mississippi and Louisiana.

Whose handling of the 1927 Mississippi flood as commerce secretary helped propel him to the presidency?

The disaster also helped elect Huey Long governor of Louisiana and pushed many Black Americans north in the Great Migration.

The Johnstown Flood of 1889 was caused by the failure of which dam upstream of the Pennsylvania town?

The reservoir was a private resort lake owned by a club of Pittsburgh millionaires connected to Carnegie Steel.

How many people did the Johnstown Flood kill?

For a while the torrent equalled the average flow of the Mississippi; Clara Barton's Red Cross mounted its first major disaster relief there.

Which Pittsburgh industrialist led the group that made the Johnstown reservoir a private resort?

The South Fork Fishing and Hunting Club's members were widely blamed, though none was held legally liable.

The Great Molasses Flood of January 1919 struck which American city?

A tank of 2.3 million gallons burst in the North End; locals claimed the area smelled of molasses on hot days for decades.

Roughly how fast did the wave of molasses travel through the streets in 1919?

It killed 21 people and injured 150; the tank belonged to the Purity Distilling Company.

The North Sea flood of 1953 was caused by what?

It struck the Netherlands, Belgium and eastern England on the night of 31 January to 1 February.

How many people died in the Netherlands in the 1953 flood, most of them in the province of Zeeland?

The Dutch call it simply the Watersnoodramp, the Flood Disaster.

The 1953 flood killed 58 people at which low-lying spot in the Thames estuary in Essex?

The car ferry Princess Victoria also sank in the same storm with 134 dead.

In response to 1953, the Netherlands built which vast system of dams and storm-surge barriers, finished in 1997?

Constructed from 1954 to 1997, it was named one of the Seven Wonders of the Modern World by American civil engineers.

The final piece of the Dutch post-1953 defences, completed in 1997, was which storm-surge barrier?

The plan changed to a movable barrier so the port of Rotterdam could stay open.

In which year was the Afsluitdijk, which turned the Zuiderzee into the IJsselmeer, closed?

It came two years ahead of schedule; the engineer Cornelis Lely gave his name to Lelystad, built on reclaimed land.

The Thames Barrier, protecting London from storm surges, has been operational since which year?

The 1953 flood prompted the Waverley Committee to recommend a barrier; the rising sector gates were Charles Draper's idea and it stands at Woolwich.

The deadly Lynmouth Flood of August 1952 followed a night of extreme rain on which upland?

About 229 mm fell in 24 hours on already saturated ground in North Devon.

The Great Flood of 1993 in the American Midwest ran along the Mississippi and which other great river?

It lasted from April to October and in some measures surpassed even the 1927 flood.

The 2010 monsoon floods along the Indus basin submerged roughly what share of Pakistan's land area?

About 20 million people were affected; UN chief Ban Ki-moon called it the worst disaster he had ever seen.

Pakistan's 2022 floods killed 1,739 people and caused about how much damage?

The climate minister claimed a third of the country was underwater; melting glaciers after a heatwave added to record monsoon rain.

Melting glaciers contributed to the 2022 Pakistan floods, causing glacial flooding in which northern region?

Warmer sea surface temperatures are also thought to intensify monsoon rainfall.

A 2007 flood in which country destroyed more than one million houses?

Long-term displacement is one of the main secondary impacts of flooding.

In the Atrahasis epic, which god secretly warns his priest of the flood and tells him to build a boat?

The story predates the Genesis narrative and shares its structure; comparable myths appear from Greece to the Americas.

The Greek counterpart of Noah, who survived Zeus's flood with his wife Pyrrha, was called what?

The Hindu tradition tells of Manu and the manvantara-sandhya flood.

Deforestation and the removal of which water-absorbing habitat increase flooding?

Straightening waterways and building levees also shift and often worsen flood risk downstream.

Climate change raises flood risk via sea-level rise and by intensifying which global process?

A warmer atmosphere holds more moisture, so extreme rain events become more frequent and stronger.

Muddy floods, where run-off picks up sediment, most often occur when overland flow crosses what?

Landslides, ice, debris and even beaver dams can obstruct drainage and worsen local flooding.

The word 'flood' can also refer to the inflow of what?

'Flood tide' is the rising tide; tidal flooding in estuaries mixes river and coastal processes.

The study of floods belongs to hydrology and which branch of engineering?

Levees, spillways and barriers are their handiwork, though levees can push the problem elsewhere.

The 1953 flood prompted Britain to eventually build what across the Thames at Woolwich?

The Waverley Committee in 1954 called for urgent study of 'a structure across the Thames which could be closed in a surge'.

The Thames Barrier is raised at which point of the tidal cycle when a surge threatens?

At low tide it reopens to let the river drain toward the sea.

Which body named the Zuiderzee Works and post-1953 Dutch defences one of the Seven Wonders of the Modern World?

The Zuiderzee scheme reclaimed some 500,000 acres of farmland and created the province of Flevoland.

The 1927 Mississippi flood left more than how many people homeless?

About 500 died; the disruption pushed many Black sharecroppers to leave the South for good.

The 1931 China floods followed which climatic sequence?

China had suffered drought from 1928 to 1931; then melting snow met sustained spring rain, and the usual three high-water seasons merged into one deluge.

What is the US National Weather Service's well-known slogan for flood safety?

It urges people to leave a flooded area rather than try to cross it, since even shallow moving water can sweep a car away.

What is a Dutch 'overlaat'?

The Beerse Overlaat on the Meuse let floodwater spill onto land judged less valuable to protect areas downstream.

According to FEMA, roughly what share of small businesses never reopen after a flooding disaster?

Wet basements alone are estimated to cut US property values by 10 to 25 percent.

The online GFMS flood-mapping tool uses rainfall data from which NASA satellite mission?

GPM data is combined with a land-surface model of vegetation, soil and terrain to estimate runoff into streams.

For roughly how long have people tried to understand and manage floodplains?

Modern work spans floodplain mapping, forecasting and emergency planning, each at different scales of time and space.

Which species is named on Wikipedia as using floods to reach new habitats?

Also called the weather fish, it benefits when inundated floodplains offer spawning grounds with few predators and plenty of nutrients.

With which country's agency does the US National Weather Service share cross-border flood forecasts?

Forecasts draw on USGS gauges, NOAA's remote-sensing centre and quantitative precipitation forecasts of rain and snowmelt.

What is the main cause of deaths directly connected to floods?

Other deaths follow from dehydration, heat stroke, heart attacks and illnesses when medical supplies cannot get through.