MYE Answers

	Section A (25m)
1	(i)	Name the instrument in Fig. 1 and describe how it is used to measure wind speed.   [3]
		-        Anemometer -        Stand at an open area where the wind flows freely. Hold up the anemometer. -        Read the wind speed off the display on the instrument. Perfect ans: Chermaine (Numbered and well explained)
	(ii)	Describe 3 common mistakes that students may make when they are using the wind vane.                                                                                                                                 [3]
		-        The wind vane may be obstructed by buildings or trees. -        The students may have used the compass wrongly to determine where the directions (North) is from. -        The students may have read the directions wrongly from the wind vane. Note: Parallax error is not accepted (no reading of measurements). Measurements is not the same as directions!!!
		Wind directions in the school field 1st Jan NE 2nd Jan N 3rd Jan N 4th Jan NE 5th Jan E 6th Jan No Wind 7th Jan No Wind 8th Jan E 9th Jan NE 10th Jan SE 11th Jan SW 12th Jan SW 13th Jan S 14th Jan SE 15th Jan No Wind 16th Jan W 17th Jan SW 18th Jan SE 19th Jan W 20th Jan W 21st Jan SE 22nd Jan E 23rd Jan E 24th Jan SE 25th Jan No Wind 26th Jan No Wind 27th Jan NE 28th Jan NW 29th Jan NW 30th Jan N 31st Jan N Table 1
	(iii)	Use the information from Table 1 to help you complete the wind rose below.                    [2]                             Note : Days with no wind = 5 (Write in the circle)
	(iv)	Winds generally come from the North direction in the month of January.’ Does the information in Table 1 supports the hypothesis? Provide evidence to justify your answer. [4]
		-        No -        There are only 4 days with wind blowing from the North, which is the same number of days as the east and northeast. -        There are 5 days of wind blowing from the Southeast directions -        The dates are on the 10th, 14th, 18th, 21st and 24th Note: Qn is not about MONSOON! Some of you see 'North' and explain abt NE monsoon wind. Majority did not provide the dates.
	(b)		A group of Xinmin students decided to investigate the amount of rainfall collected in the school compound in the month of February. Table 2 shows the amount of rainfall collected at the field. Date and Rainfall collected (mm) 1/2/17 – 1 mm 8/2/17 – 0 mm 15/2/17 – 0 mm 22/2/17 – 0 mm 2/2/17 – 3 mm 9/2/17 –  5 mm 16/2/17 – 0.5 mm 23/2/17 – 1 mm 3/2/17 – 2 mm 10/2/17 – 2.5 mm 17/2/17 – 0 mm 24/2/17 – 0 mm 4/2/17 – 0.5 mm 11/2/17 – 3 mm 18/2/17 – 0.5 mm 25/2/17 – 2 mm 5/2/17 – 2.5 mm 12/2/17 – 0 mm 19/2/17 – 8 mm 26/2/17 – 3 mm 6/2/17 – 0 mm 13/2/17 – 0 mm 20/2/17 – 6 mm 27/2/17 – 1.5 mm 7/2/17 – 5 mm 14/2/17 – 0 mm 21/2/17 – 0 mm 28/2/17 – 0 mm Table 2
		(i)	Name the instrument that the students used to collect precipitation in the school field. Describe the steps taken to use the instrument correctly.                             [4] -        Rain gauge -        Locate a spot on the field that is not obstructed by any buildings or trees. -        Dig a hole in the ground that is deep enough to place the rain gauge in with 30cm of it protruding above the ground. -     Pour the collected water and record the readings from the measuring cylinder
		(ii)	Calculate the total amount of precipitation collected for February.                                      Total = 47mm	[1]
		(iii)	Calculate the mean amount of precipitation collected for the first week of February.                                       Total = 14mm / 7 days = 2mm Note: FIRST WEEK OF FEB!!! Many of u calculated the mean for the whole month	[2]
		(iv)	The students came up with the following hypothesis ‘The school experiences low rainfall during the month of February’. How far does the data in Table 2 support the following hypothesis?                   [3] -        The data supports the hypothesis to a large extent. (1m) -        There are 11 days without any rain, and majority of the days have very little rainfall. -        The highest rainfall recorded is very low at 8mm on 19th February. -     Total amount of rainfall is 47mm only Note : Qn is NOT related to monsoon. Use data from Table 2. Shuwen, Nadia has a well written answer
		(iv)	The students were tasked to present their findings for the first week of February. Complete the bar graph below to show the amount of precipitation collected in the school.	[3]
			Amount of Rainfall (mm) 7 6 5 4 3 2 1 0 1/2 2/2 3/2 4/2 5/2 6/2 7/2 (Date)

 Section B (25 marks)

2	(a)	Study Fig. 2 which shows the coverage of clouds in city X during the day and night.
		Describe how the presence of clouds affects temperature in city X during the day and night.                                                                                                                                 [3]
		-        During the day and night, there is presence of cloud cover. This results in a small temperature difference between day and night. -        During the day, clouds reflects a large portion of the sun’s energy back to space. This keeps the temperature cool. -        During the night, clouds absorb most of the heat that is radiated from the earth’s surface and prevent it from escaping into space. This keeps the temperature warm. Note : Most students did not write the first point on 'presence of cloud cover'.  Convectional rain is not the same as RELIEF rain!!! Many of you still cannot spell CUMULONIMBUS clouds.  High scorer: Chermaine, Shuwen
	(b)	Using an annotated diagram, explain how convectional rainfall is formed.                         [6]                                                                                                         Land   Diagram (2m) -        Solar radiation, hot air expands and rises, Cumulonimbus Clouds, Convectional Rain Explain (4m) -        The sun’s energy heats up the earth’s surface intensely and causes air to expand and rise. -        As the air rises, it cools. Air temperature reaches dew point temperature and condensation occurs. -        Cumulonimbus clouds are formed. -        When water droplets become large and heavy enough, they fall to the ground as convectional rain.
	(c)	Sea breeze (a)  _Low__Pressure Land (b)  _Low_Temperature Sea
	(d)	(i) Name the monsoon wind shown in Fig. 4.                                                                     [1]      Northeast Monsoon Wind
	(d)	(ii) Explain the influence of the monsoon wind on rainfall patterns in Singapore as shown in Fig. 4.                                                                                                                             [4]
		-        In January, the northern hemisphere experiences winter, while the southern hemisphere experiences summer. -        As such an area of high pressure is formed over Central Asia, while an area of low pressure is formed over Australia. -        Wind moves from Central Asia towards Singapore from a high pressure to low pressure area. -        The air picks up moisture as it travels over the South-China Sea and brings heavy rain to Singapore.
	(e)	With reference to Fig. 5 and 6, identify the country that is more favorable for agriculture. Suggest reasons for your choice.                                                                                    [3] -        Country A. -        Country A has high precipitation consistently throughout the months from January to December. The lowest precipitation is in December with 500mm and the highest is in May and June with 660mm. -        This would ensure that crops receive sufficient rainfall every month and would not wither due to a lack of rainfall.
		Note: Data is not provided by most students. Should give RAINFALL data as the temperature is similar for A and B. Rainfall is the main difference.  Shuwen and Anna has a very detailed answer. (Not necessary  to discuss about temperature)
	(f)	National efforts to combat climate change are more effective than International agreements.’ How far do you agree with the statement? Use examples to support your answer.       [6]

Introduction : Take a stand (Agree/Disagree)

Compulsory factor: National effort (Singapore Green mark scheme/ plant-a-tree/ green plan.

Other factor: International effort (Kyoto Protocol)

Factor	Description	Success	Limitation
National (Sg) -        Singapore Green mark scheme	To construct ‘Green buildings’ that are more energy efficient. Thus uses less  energy to provide the same service.	Plaza by the park, SCB at Changi, National Library have reported energy savings of 15-35% compared with convectional buildings.	More costly to build as the materials are more expensive such as bamboo and recycled metal.
National (Sg) -        Plant a tree campaign	To plant trees regularly in Singapore and to encourage residents to donate money to buy a tree.	60,000 trees are planted yearly by Nparks.	Trees take many years to mature and positive effects takes time to materialize. Eg 25 years for angsanas to reach full height.
National (Sg) -        Green plan	To generate 60% of Singapore’s energy needs using natural gas by 2012.	As early as 2010, about 79% of Singapore’s electricity was generated from natural gas.	High maintenance cost of the pipelines to transport natural gas from plants to homes.
International -        Kyoto protocol	Agreement to reduce the levels of greenhouse gases in the atmosphere.	Many countries met or exceeded the targets set by the protocol eg Austria, Finland. The protocol was successful in encouraging sustainable development.	There were still countries like Denmark, Sweden and UK that did not achieve their targets. Countries that did not signed the protocol like China and India contributed significantly to the global emissions.

Level 1 (0 - 2 marks)

At this level answers will be generalized 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.

Award L1/1 for answer limited to simple listing of one or two factor.

Award L1/2 for answer with description of one or two factor

Level 2 (3 - 4 marks)

Disagreement and 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.

Award L2/3 for answer with balanced evaluation of at least two factors.

Award L2/4 for answer with balanced evaluation of at least two factors with at least ONE example given.

Level 3 (5 - 6 marks)

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.

Award L3/5 for answer with balanced evaluation of at least two factors, with at least TWO examples given.

Award L3/6 for answer with balanced evaluation of at least two factors, with a good conclusion stated.              

Note : Anna, Wai Teng, Nadia, Enzo, Chikin, Jocelyn and Xinyi has L3/5. Very well written but weak conclusion. Conclusion you need to provide some suggestions. So if you wrote the first point as Green scheme, your conclusion can be on Green plan/ Plant a tree. 

L3/6 - Xuan Chan (Conclusion: Feels that national movement is more effective as there wasnt a set target for interntional, and some countries met their targets as they set lower standards)

please use PARAGRAPHS!! Very difficult to mark!!