O-LevelGeographyThe natural environment2217/11 · Oct/Nov 2010 · Q425 Marks

(a) Study Fig. 6, which shows the location of tropical deserts. [Figure 6.0] (b) Study Photograph B (Insert), which shows vegetation in a tropical desert.

(a)(i)Name a tropical desert in the Northern Hemisphere.[1]
(a)(ii)Describe the location of the Atacama desert.[2]
(a)(iii)Describe and explain the main characteristics of daytime and night-time temperatures in tropical deserts.[3]
(a)(iv)Explain why tropical desert areas have an annual precipitation of less than 250mm. You may use labelled diagrams or sketch maps in your answer.[4]
(b)(i)Describe the main features of the vegetation shown in Photograph B.[3]
(b)(ii)Explain the relationship between the climate and the natural vegetation in tropical desert areas.[5]
(c)For a named tropical desert, explain how and why the natural environment is threatened by human activities.[7]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2010). The mark or mark type is shown in brackets.

[1] SW USA/Sahara/Thar/Arabian
[1] In South America;
[1] Around Tropic of Capricorn/23.5S;
[1] West of land mass/near Pacific Ocean/West coast;
[1] In Chile/Peru (accept either);
[1] Between Andes and the coast;
[1] In southern hemisphere;
[1] high daytime temperatures (desc);
[1] high angle of sun/absence of cloud (exp)
[1] low night time temperatures (desc);
[1] absence of cloud/heat escapes (exp)
[1] A long way from oceans;
[1] Not close to sea/large lake;
[1] Trade winds;
[1] Blow over large areas of land hence no source of moisture;
[1] Rain shadow;
[1] High pressure;
[1] Scattered/sparse vegetation;
[1] Low shrubs/bushes/scrub;
[1] Cacti;
[1] Palm trees;
[1] Plants with narrow leaves/spines/spiky;
[1] Low precipitation (aridity) results in scattered (sparse) vegetation;
[1] Seeds (plants) remain dormant during long dry spells;
[1] Narrow (spiky) leaves reduce rates of evapotranspiration/because of high temperatures;
[1] long roots (wide spreading roots) search for water;
[1] Some plants (cacti) store water in order to survive long periods of drought
Level 1 (1-3 marks) Statements including limited detail explaining how the area is at risk/threatened from human activities. (e.g. the area is used for farming, resources/oil is mined/drilled in the area, animals are killed, tourists destroy dunes etc.)
Level 2 (4–6 marks) Max 5 marks if no named example. 3 developed statements plus named example for 6 marks. More developed statements explaining why the area is at risk/threatened from human activities. (e.g. large herds of animals are grazed in the area which destroys pastures, resources/oil is mined/drilled in the area and wildlife is killed as habitat is destroyed, the use of quad bikes/trampling on the dunes wears them away etc.)
Level 3 (7 marks) Uses named example (e.g. Arabian Desert). Comprehensive and accurate statements explaining how and why the area is at risk from human activities, including some place specific reference. [NB For place specific reference candidates could name specific parts of the desert or countries affected.]