O-LevelGeographyThe natural environment2217/13 · May/June 2015 · Q425 Marks

Study Fig. 5, which shows a climate graph for Jornada, an area in the Chihuahuan Desert of Mexico. average monthly temperature (°C) 40 30 20 10 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec year 80 70 60 50 average monthly precipitation (mm) 40 30 20 Key ** temperature precipitation 10 0 Fig. 5

(a)(i)Estimate the annual precipitation of Jornada. Underline your answer. 25 mm 65 mm 240 mm 465 mm[1]
(a)(ii)Compare the average monthly precipitation at Jornada in January and July. You should include statistics in your answer.[2]
(a)(iii)Describe the variation in temperature at Jornada during the year. You should refer to data from Fig. 5.[3]
(a)(iv)Explain why the temperatures in tropical deserts: vary during the year; change from day to night.[4]
(b)(i)Describe the location of the Chihuahuan desert.[3]
(b)(ii)Suggest reasons why the rainfall is low in the Chihuahuan desert.[5]
(c)For a named area of tropical desert you have studied, explain how the vegetation and wildlife are adapted to the climate. Name of tropical desert[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 (May/June 2015). The mark or mark type is shown in brackets.

[1] (a) (i) 240mm
[2] (ii) July higher than January/or vice versa/more in July;
[2] July (56mm) January (8–10mm)/6 times more in July/46–48mm more in July;
[2] NB: mm not needed.
[3] (iii) Ideas such as:
[3] • range of 24°C or statistics – 13 to 37°C;
[3] • increases January to June/higher in June compared with Jan etc;
[3] • decreases June to December/higher in June compared with Dec etc.;
[3] • any two statistics Max 1;
[3] NB: Can accept summer and winter as alternatives to months.
[4] (iv) Vary during the year:
[4] • angle of sun changes/tilt of the earth;
[4] • higher angle April to August/directly overhead/sun's rays more concentrated/lower angle September to March.
[4] • Change from day to night:
[4] • No cloud cover;
[4] • Sun heats up area in day but heat escapes at night; etc.
[3] (b) (i) Ideas such as:
[3] • on and around border of USA and Mexico/or variants e.g. mainly in Mexico/Northern Mexico;
[3] • mainly in States of New Mexico/Chihuahua/Coachuila/Arizona/Texas (Any two needed);
[3] • North of Tropic of Cancer/between latitude 24°N – 31+°N/mainly between Tropic of Cancer and 30°N;
[3] • east of Sierra Madre Occidental/bordered by mountains to West;
[3] • between 100 – 110°W longitude; etc.
[3] NB: Distance and direction from any named feature except oceans.
[5] (ii) Ideas such as;
[5] • high pressure;
[5] • descending air;
[5] • so there is no cooling/condensation (dev);
[5] • in a rain shadow;
[5] • rain bearing winds more likely to fall on mountains to west (dev);
[5] • inland location/long way from sea/not near any water bodies;
[5] • winds will be dry by the time they reach the area (dev); etc.
[7] (c) Levels marking
[7] Level 1 (1–3 marks) Statements including limited detail which explain how vegetation and/or wildlife have adapted to desert climate.
[7] Level 2 (4–6 marks) Uses named example. More developed statements which explain how vegetation and/or wildlife have adapted to desert climate. NB: Max 5 if no named example
[7] Level 3 (7 marks) Uses named example. Comprehensive and accurate statements which explain how vegetation and wildlife have adapted to desert climate, including some place specific reference.
[7] Content Guide: Adaptations are likely to include features of plants and animals such as; • long/wide roots, • fleshy stems, • thorns etc. • humps, • long eyelashes etc.
[7] Place specific reference is likely to consist of: named parts of the desert; named species etc.