What physical factors control water supply?

Question 1

Explaining why precipitation varies..

Answer 1

Global atmospheric circulation- high and low pressure
Proximity to the ocean.
Occurrence of warm and cold ocean currents
Prevailing wind patterns
Altitude
Cyclical variations

Question 2

Precipitation varies because of a global circulation of high and low pressures…

Answer 2

Hot air expands, rises and causes heavy rainfall and thunderstorms.
Low pressure means rain.
To replace the risen air- the air surrounding is sucked in- convection current created.
High pressure air that falls again gives dry conditions.
(where we are) Mid latitude experiences a combination.

Question 3

Proximity to the ocean…

Answer 3

Wetter near the ocean.

Processes such as evaporation more likely to occur.

Question 4

Occurrence of warm and cold ocean currents…

Answer 4

Warmer current of your coast will mean wetter conditions as evaporation is more likely to occur

Question 5

Prevailing wind patterns…

Answer 5

Wettest conditions will mean the prevailing wind is facing inland.

Question 6

Altitude…

Answer 6

Higher generally means wetter- because air is forced to rise up and as it cools it condenses.

Question 7

Cyclical variations…

Answer 7

El Nino

Question 8

How do river systems affect water supply?

Answer 8

Rivers can transfer water from areas of water surplus to areas of water deficit, e.g The River Nile
River flow can very seasonal as well.

Question 9

How does subsurface geology affect water supply?

Answer 9

Aquifer: underground store of water.
Some water infiltrates into the soil and percolates into rock.
Permeable-porous- ‘water stored into a rock like a sponge’.
•Water is stored in porous rocks in the ground. The water table marks the surface of this.
•Sandstone and chalk are porous, however the best stores are sands and gravels that are unconsolidated, so have high porosity and are bounded by impermeable rocks.

‘modern’ ground water- currently being recharged by rainwater.
‘fossil’ groundwater- aquifers from thousands of years ago when climate was better.

Question 10

Snowy Mountain Project, Australia

Answer 10

This scheme came into place after the Second World War, 1949
It involved diverting water from the Snowy Mountains to flow inland rather than to the east coast.
This involved dams and tunnels and eventually cost a billion Australian dollars.
It was also about Australia stating they were a world power.