Q 01/05

Which type of dam relies on its own sheer weight to hold back the water?

A) Gravity dam

B) Buttress dam

C) Cofferdam

D) Arch dam

Answer · why

A) Gravity dam

Gravity dam: it is proportioned so that its own weight alone resists the water's push to slide it or tip it over, which is why these dams are such bro...

Q 02/05

An arch dam is curved in which direction?

A) Downstream, away from the water

B) Sideways along the valley

C) Upstream, into the reservoir

D) Neither, it is straight in plan

Answer · why

C) Upstream, into the reservoir

Upstream, into the reservoir: the water presses on the outside of the curve and squeezes the arch into the gorge walls, keeping its joints closed, so ...

Q 03/05

Under what name was Hoover Dam commonly known from 1933 until Congress settled the matter in 1947?

A) Black Canyon Dam

B) Boulder Dam

C) Roosevelt Dam

D) Colorado Dam

Answer · why

B) Boulder Dam

Boulder Dam: after Hoover left office the Interior Department avoided his name, allegedly because the new Secretary disliked him, until a 1947 resolut...

Q 04/05

The Sadd el-Kafara, the oldest large dam known, was built around 2600 BCE by which civilisation?

A) The ancient Sumerians

B) The ancient Minoans

C) The ancient Egyptians

D) The ancient Hittites

Answer · why

C) The ancient Egyptians

The ancient Egyptians: they raised the 14-metre embankment across a ravine to hold back rare, violent floods, and one of those floods is thought to ha...

Q 05/05

Roughly what share of the world's arable land is irrigated with water from reservoirs behind dams?

A) About 5%

B) About 20%

C) About 40%

D) About 60%

Answer · why

B) About 20%

Irrigation, hydropower, water supply, flood control, navigation and fish farming are the main jobs dams do.