Ithome 4sept - Ans

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Geography Sec 3 IT Home Learning HWA CHONG INSTITUTION High School Section

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Sec 3 Q

Marks:

/25

1a) Study photograph A which shows a type of natural vegetation. Identify the type of natural vegetation.

[1]

Mangrove Forest [1m] Account for how it adapts to the surrounding environment. Award 1m for each well-elaborated point. Answers must include all 3 categories: roots, leaves and fruits. Max 2m for each category.

[6]

Roots: • pencil-like, conical shaped that protrude out of the mud to absorb the air when exposed during low tide • prop roots to anchor trees firmly into muddy ground • aerial roots that jut out of mud to take in oxygen • some roots have salt excluders to exclude salt when they absorb the sea water Leaves: • Thick and leathery to reduce excessive transpiration • Special salt glands to excrete salt • Storing salt in old leaves that will drop off • Drip tips and waxy texture to remove excess water Fruits: • Sharp end of fruit falls and anchors itself firmly in the mud like a javelin • Buoyant fruits that can float in the sea for some time before taking root b) Fig. 1below shows the climograph of a type of climate. Identify and describe the type of climate shown in Figure 3 above. Award 1m for identification of climate, 3m for description

[4]

Tropical Monsoon climate [1m] High mean monthly [1/2m] temperature of about 25.1ºC [1/2m] (accept +/- 0.2°C) Moderate [1/2m] total annual rainfall of about 800mm [1/2m] (accept +/- 5mm) It has a distinct wet season between June and Sept and a distinct dry season between Oct to May. [1m] [1/2m if months not given] Do not accept such answers: It has a high temperature It has highest temperature of 34ºC and lowest temp of 14ºC

Nancy Tay

1

04/09/2009

It has a low rainfall c) Fig. 2 below shows a map of North America. With close reference to Fig. 2 above, account for the variations in temperatures [6] between San Francisco and Winnipeg. Award 1m for identification of factor, 2m for explanation. Difference in Latitude [1m] Winnipeg – higher latitudes, temperature colder as angle of sun’s incidence is larger thus heat and sunlight is less concentrated and spread over a larger area. [1m] San Francisco – Nearer to equator, warmer temperatures as the angle of sun’s incidence is smaller thus more concentrated amount of sunlight and heat is received. [1m] Distance from the sea [1m] Winnipeg subjected to continental influence [1/2m]: hotter summers and colder winters because they do not receive moderating effects from the ocean. [1/2m] San Francisco subjected to maritime influence [1/2m]: cooler summers and warmer winters because they are moderated by influence from the ocean. [1/2m]

Nancy Tay

2

04/09/2009

d) Evaluate the success of afforestation, water storage and cloud seeding in alleviating the problems resulting from drought. [8] Students may include following material: Afforestation

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Water Storage

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Success Provides shade for the ground and lowers temperature Veg cover prevents surface runoff, allowing more water to seep into the ground when it rains Agenda 21 report proposed by UN – making efforts to increase vegetation in drought affected regions Eg. Mongolia Facilities constructed such as dams and tanks to accumulate water in the event of a drought Rainwater harvesting in Australia Irrigation – water channeled in from elsewhere Water diverted from Colorado river to deserts in S. California Artificial rain through aeroplanes or rockets Does not require construction of permanent structures like dam Countries like China, Thailand and Malaysia have practiced cloud seeding

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Challenge Govt focus is on economic development and not the envt esp for less developed countries Money and resources are used to build infrastructure and development due to land scarcity Corrupt govt interested only in making money

Expensive to construct large dams Resources limited in less developed countries Canals connect to rivers for irrigation become useless when rivers dry up during dry periods Unable to control climate and drought from occurring (global warming) Too expensive for less developed countries to afford Method is not always effective

Level 1 (0-3marks) Simple statements on 1 or more of the factors No examples given No reference to drought Level 2 (4-6marks) At least 1 or more detailed statement on each factor General examples given

Nancy Tay

3

04/09/2009

Award 4m – one sided answer, i.e. success or challenges only Level 3 (7-8marks) Balanced answers must be given, clear counter arguments Detailed statements on each factor Specific examples given

Nancy Tay

4

04/09/2009