Q 01/05

In which Arizona slot canyon did a 1997 flash flood kill a group of tourists?

A) Canyon de Chelly

B) Antelope Canyon

C) Oak Creek Canyon

D) Sabino Canyon

Answer · why

B) Antelope Canyon

Antelope Canyon: hardly any rain fell there that day, but runoff from a thunderstorm upstream funnelled into the narrow slot.

Q 02/05

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

A) coastal

B) areal

C) tidal

D) muddy

Answer · why

B) areal

Areal flooding: on flat ground such as floodplains and endorheic basins, rain arrives faster than saturated or frozen soil can absorb it or the land c...

Q 03/05

Which US city suffered three '500-year' floods in three straight years?

A) New Orleans

B) Miami

C) Houston

D) Charleston

Answer · why

C) Houston

Houston: a '500-year' flood only has a 1 in 500 chance each year, so another can follow soon after, as Hurricane Harvey's did in 2017.

Q 04/05

Which crop do farmers grow in fields they deliberately keep flooded?

A) wheat

B) sugar cane

C) cotton

D) rice

Answer · why

D) rice

Rice: paddies usually stay flooded until about a week before harvest, which makes lowland rice a very thirsty crop.

Q 05/05

Which waterborne disease often spreads after floods taint drinking water with sewage?

A) cholera

B) malaria

C) typhus

D) dengue

Answer · why

A) cholera

Cholera: in 1854 John Snow traced a London outbreak to one contaminated street pump, and local officials removed its handle.