Identify which state has the largest area of named deserts.

Identify the two deserts with the greatest longitudinal (east to west) extent.

Outline one reason why rainfall is low in hot, arid deserts.

Explain two challenges that low rainfall creates for agriculture in inland deserts such as those shown on the map.

Western Australia.

Great Sandy Desert and Great Victoria Desert.

Both are needed for [1].

Award [1] for the reason and [1] for some explanation of how it limits rainfall.

Diagrams should be given credit.

For example: Rain shadow [1] due to descending dry air on leeward side of a mountain range [1].

Other possibilities include:

• cold ocean currents
• latitude/sub-tropical high pressure
• continentality / interior.

The challenges may relate to difficulties growing crops or raising livestock in arid environments, or finding alternative water resources because of inaccessibility.

Award [1] for each challenge and up to [2] for further development / explanation / exemplification.

For example, desertification can occur due to the dryness of the soil [1], and susceptibility to wind erosion [1] results in loss of soil for plant roots [1].

Other possible challenges include, but are not limited to:

• salinization
• problems with water collection and storage, cost of irrigation systems.
• problems with locating/accessing underground aquifers
• competition with other water users.

(a)(i) and (ii) Generally fine although there were a number who misunderstood the meaning of longitude.

(a)(i) and (ii) Generally fine although there were a number who misunderstood the meaning of longitude.

Whilst there were some good answers using continentality or the rain shadow, many did not understand why rainfall is low in hot, arid deserts.

"Challenges for agriculture" was reasonably well understood but lacked development or explanation.