Thursday, August 25, 2016

2014 N level Q5

5
(a)
Annotate Fig. 10 to explain how convectional rainfall is caused.  [4]  - don’t leave any line for students











Fig. 10







Fig. 10 should have the following information:
  • Sun’s energy reaches the earth
  • The earth’s surface is heated by sun’s energy.  In turn, heats up the surrounding air.
  • Warm air rises and expands
  • Air cools on rising.  Reaches dew point temperature and condensation takes place / condensation level [the horizontal line below the cloud]
  • When the droplets are huge enough, there will be conventional rain, which is followed by thunder and lightning










(b)
Study Fig. 11A and 11B which show a hygrometer and a relative humidity table.



















(c)
Using Figs 11A and 11B, state the relative humidity.  Explain how you have used the hygrometer and table to calculate the relative humidity.                                                  [4]







Relative humidity:  63 %

Explanation
  • Read dry bulb temperature 25 C; read wet bulb temperature 20 C
  • Find the wet bulb depression; the difference between the dry bulb temperature and wet bulb temperature
  • Read the conversion table to derive the Relative Humidity percentage







(c)
Study Fig. 12, a graph which shows the average annual temperatures for Singapore over 63 years.










Fig. 12







Describe the trends in average temperatures for Singapore, as shown in Fig. 12.  [4]



  • Singapore average temperature on the rise; from 26.75C to 28 C
  • Increase by 1.25 C over 30 years from 1950 to 1980
  • After 1980, temperature increase
  • Highest in 1990, reaches average of 28.75 C

4@1m






(d)
What strategies are countries, such as Singapore, developing in response to climate change?                                                                                                                           [4]



National strategies required:  Singapore
  • Singapore Green Plan 2012 … reduce greenhouse gases by using natural gas as energy
  • Plant-A-Tree Programme … because the trees are green lungs of the environments as they remove carbon dioxide from the atmosphere
  • Green Mark Scheme … construct green building which are energy-efficient and environmentally friendly; such buildings cut down greenhouse gas emissions by reducing the use of fossil fuels to generate electricity
  • Use less energy to provide same service; e.g. using solar energy

National strategies required:  India
  • Energy labelling programme … reduce energy consumption by labelling frost-free products like refrigerators, fluorescent lamps and air conditioners, laptops … by using such products there will be energy conservation which helps to reduce nation’s greenhouse gas emissions.

  • National Urban transport Policy … emphasizing public transport … encourage public to take public transport like buses and rail
  • By expanding the rail network, people will take the rail and keep vehicles off the roads and reduce greenhouse gas emissions

4@1m
[Can use India’s examples]






(e)(i)
Describe a tsunami and explain how it is caused.                                                           [4]



Describe:
  • A huge wave

Causes
  • Formed by earthquake in the sea
  • Wave on reaching shallower water, greater friction slows waves and forces waves to increase in height
  • When tsunami reaches coast, speed of tsunami reaches 30 – 50 km/h and height of 15m

Reserve 1m – describe a tsunami






(ii)
‘The impact of a tsunami on people’s lives can be more devastating than that of an earthquakes.’
How far do you agree with this statement?  Give reasons for your answer.                    [6]







Impact of tsunami
Destruction to coastal areas
2004 … 9.2 magnitude earthquake in Indian Ocean, triggered tsunami
Damage coastal settlements in 12 countries
Most damage to western Sumatra, Aceh.
Tsunami … 4- 39 metres high swept 10km inland.  Houses swept away.

Impact of earthquakes [any 2 with examples]
Disruption to services
Fires
Landslides
Loss of lives and properties










Level 1
(0 - 2m)
At this level answers will be generalised or with minimal support if any stand were given at all.
Reasoning rather weak and expression may be unclear.
A basic answer that has little development.


Level 2
(3 - 4m)
Disagreement or agreement will be supported by appropriate detail.
Or, both agreement and disagreement are considered, but support is patchy so that the answer is not full. 
Good reasoning and logic in parts of the answer with good expression in places.

Level 3
(5 - 6m)
At this level answers will be supported by sound knowledge.
Both agreement and disagreement are considered and well supported. 
Reasoning is clear and logical with good expression of language.








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