Water revision

Identify the missing process in the diagram.

• Infiltration

• Interception

• Percolation

• Transpiration

What type of system is the hydrological cycle?

• Open

• Closed

• Isolated

• Partial

Answer explanation

The hydrological cycle is a closed system because water does not leave Earth. There is a finite amount of water that circulates within the water cycle.

Which of the following stores of water has the longest residence time?

• Atmosphere

• Snow

• Deep groundwater

• Antarctica

Answer explanation

Water molecules that reach Antarctica spend on average 20,000 years there (residence time) compared to 10 days for the atmosphere, 10,000 years for deep groundwater and 2–6 months for snow.

What percentage of the world’s precipitation falls directly into the oceans and seas ?

• 78%

• 87%

• 57%

• 67%

Answer explanation

This is slightly more than the 71% of Earth’s surface covered by oceans. Very little precipitation falls over polar land masses, whereas a lot of precipitation falls over equatorial oceans.

What geographical term is used to describe the annual variation is the discharge of a river system ?

• River Seasonality

• River Hydrograph

• River regime

2.0% of global water is located where?

• Lakes

• As ice

• In rivers

• Groundwater

Answer explanation

In ice. The percentages for the other answers are:

Lakes 0.1%

Rivers 0.001%

Groundwater 0.68%

97.25% of water is in the oceans.

Which of these is a key physical factor in the causation of drought?

• Food supply

• Precipitation

• Urbanisation

Answer explanation

Drought is a period of below-average precipitation leading to a shortage of available water

The region shown on the map below often experiences drought. Name the region.

• The Sierra

• The Sahara

• The Sahel

• The Sudan

Answer explanation

This is a semi-arid region south of the Sahara Desert that has experienced frequent drought especially since the late 1960s. The Sahara Desert does not experience drought because it is arid to start with. Its rainfall is so negligible drought isn’t really possible

Which climate phenomenon that originates in the Pacific is often linked to the onset of drought conditions?

• NAO

• AMD

• WTO

• ENSO

Answer explanation

The El Niño Southern Oscillation and its El Niño/La Niña cycles are often cited as a cause of drought because of their ability to shift the locations of high and low air pressure. Two of the other answers are climate oscillations: the North Atlantic Oscillation and Atlantic Multi Decadal oscillation, more often linked to hurricane and storm frequency than drought.

According to the UN Food and Agriculture Organisation, what are the annual global losses from drought?

• US$60–80 million

• US$600–800 million

• US$6–8 billion

• US$6–8 million

Answer explanation

A 2014 report by FAO estimated this cost. Taken long term, drought ranks alongside earthquakes in terms of financial losses. Drought also affects very large areas and can last years or even up to a decade.