Grid reference

1. Always remember to read from the bottom left corner.

2. If the question ask for the four-figure grid reference or grid square of a particular building, e.g. the Hindu temple shown in Fig 1. Read the number for the easting first (from the X axis) and then the northings (from the Y axis). E.g example in Fig.1 is located in 2672

3. If the question ask for the six-figure grid reference or grid square of a particular building, e.g. the Hindu temple shown in Fig 2. Start by finding the grid square with the feature, then divide the grid square into 10 equal parts along both the northings and eastings. Place a ruler onto the bottom left corner of the feature, e.g. the Hindu temple is located at 266727. Read the number for the easting first (from the X axis) and then the northings (from the Y axis).

Direction

To measure the direction of one point to another, draw a straight line connecting them.

• Read the question carefully– if the question ask you the direction of B from A, then draw a + sign at A and read the direction from A.

Bearing

• Draw a straight line connecting the 2 points.



• Draw a + sign at where you are taking the bearing from.
• Place the protractor at the + sign with 0° facing north and then read the bearings from the point starting from 0° (north) clockwise as shown in Fig.4.

Height
The height of a place above sea level can also be indicated by the contour lines.
Contours are imaginary lines connecting areas of the same height above sea level on a map.
The contour lines can be used to show the relief of a place such as whether the slope is gentle or steep. The spacing of the contours indicate the steepness of a slope – the closer the contours the steeper the slope and vice versa.

a) valley – associated with rivers, tend to be V-shaped and narrow in the upper course, broader in the lower course
b) plateau – elevated land with flat top and steep sides
c) escarpment – continuous line of steep slope at the edge of a ridge or plateau.

Guide to describing relief
Give the average height ( or the range of height) of the relief of the area and state the height of the highest point.

Describe the relief of the area:
(a) state whether it is mountainous or hilly or whether it is part of a plateau. Point out and describe any relief feature that stands out in the area and state its location on the map.
(b) Describe the slopes in the area. States whether they are concave. Convex, uniform, steep or gently sloping.

Example of how you can describe relief:
The height of the area ranges from below 10 metres near to the coast to 548 metres in grid square 8483.
The main relief feature is T Mountain which is in the western part of the area. As the mountain extends to the south-east, it becomes narrower and its height decreases. This part of the mountain has two peaks of heights about 240 metres in grid square 8582 and about 110 metres in grid square 8682. This part of the mountain also has two spurs from grid square 8583 to 8683 extending from south-west to north-east.
The contours of T Mountain are very close together in the area west of easting 85. This indicates that the slopes are steep. The spacing of the contours on the eastern side of the mountain is wider. The slopes here are therefore less steep.

Steps taken to measure gradient
Identify the two points which the measurement is taken from and the height above sea level for the two points. You can either refer to the spot heights, the bench marks or the contour lines.
Calculate the height difference (vertical distance) of the two points.
Convert the height to the same unit of measurement as for horizontal distance if necessary e.g. 3.048 feet = 1metre
Measure the distance of the 2 points on the map. Convert to actual distance by referring to the line scale or using the map scale ie. 1: 50,000 means 1 cm on the map represents 500m in actual distance.
Gradient is expressed in ratio form – vertical distance: horizontal distance ie. 1: 30 - which means for every 1 metre increase in vertical distance, there is an increase of 30 metres in horizontal distance.

River Studies

Describing River
a) drainage pattern ie – dendritic, trellis or radial
b) area drained – many tributaries joining the main river etc
c) direction of flow- the river flows from a higher ground to lower ground or towards the sea.
d) Course of river – ie. Straight or meandering, braiding, width
e) Presence of river features e.g rapids, waterfall

Drainage pattern
The drainage pattern of river is determined by the relief and the geological features of the land over which the river flows.

Drainage density

Refers to the number of streams on the land surface. The greater the number, the higher the density. Drainage density is highest in areas with impermeable rock of fine texture and heavy rainfall.

River valley
Wide valley floor as indicated by the widely spaced contour lines which increases in value away from both banks of the river.
V-shaped valley with steep slopes – indicated by closely packed contour lines which increases in value away from both banks of the river,
Flat valley floor as indicated by the absence of contour lines immediate to both banks of the river.

Evidence of water supply
Reservoir
Pump house
Pipeline

Settlement Pattern

a) Dispersed – houses far apart – areas with low economic development e.g. normadic herding, smallholdings
b) Linear – arranged in a line, usually along a mode of transport ( rail, road) or waterway (river, coast) to take advantage of the accessibility and resources.
c) Nucleated – concentration of buildings or houses – usually at road junctions or centers of economic activities ( e.g. community or village with facilities like school and shops)

Choice of site for the location of airport, plantation, settlement etc.
Availability of large area of flat land, ability to expand, very accessible e.g. near to rail or roads, availability of services or resources – remember to look closely at the map symbols on the map and refer to the legend of the map.

E.g. of question on Geography of food
Describe the type of food production in the map area and explain the importance of the roads to it.
The main food production is the growing of sugar-cane to be made into sugar as shown by the presence of large area under sugar plantation and the presence of sugar mill. The roads are important for the transportation of sugar-cane other settlements for refining or for sale. It also allows workers to be transported from their homes to the plantations and back.

E.g of question on development:
A new agricultural training centre is to be set up at either X or Y. Which site do you support and why?
An agricultural training centre is likely to provide training for farmers, both locally and within the country, as well as be engaged in research and development.
Y is the better site because:
• it is surrounded by agricultural areas — permanent cultivation (all around except to the south and southwest), a chicken farm (to the northwest), some coconut plantations (to the southwest) — these farmers are likely to be keen to undergo training.
• it is a growing town with a larger population compared to X, so it should not be difficult to get students for training.
• It is accessible by road to X and other parts of the country e.g. Z — major road, secondary roads.
• The town has all the necessary services and facilities to support its set up — bank (capital investment), telecommunications (links to other parts of the country), medical facilities and other services (supporting services).
• There is available land on the outskirts of the town for the centre but not to the east of the town, where there are swamps and the river and streams may overflow and flood the area.

World Watch on Channel News Asia 15 Oct 2009

Just saw this report on TV – in Iceland, all the electricity is generated from renewable energy resources. 80% of the electricity is generated from hydro sources - rivers and glaciers and the other 20% from geothermal source. Geothermal sources are also used to heat houses and warm the roads so that it is snow free in winter. I am truly impressed that a country can be fully dependent on renewable natural resources to produce adequate energy supply for the country.

As countries developed, the need for energy resources has increased and there is a real urgency in looking at alternative energy resources. In Brazil most of the cars run on biofuel - ethanol produced from sugar cane. We are also looking into producing biofuel from palm oil. Of course there are still controversies in the use of biofuel as an alternative as its production takes up agricultural land which could have otherwise used for food production.

Read about the rise in world hunger on the Straits Times 14 Oct 09 -http://www.straitstimes.com/Breaking%2BNews/World/Story/STIStory_442139.html

The number of undernourished people started climbing in 1995, reaching 1.02 billion this year under the combined effect of high food prices and the global financial meltdown, the agency said. The figure topped the 1 billion mark in June, and was 963 million a year ago.

Why more hungry people?
· Soaring prices for food staples in 2007 and 2008 forced poor families to sell their meagre assets and cut down on meals, health and education spending. Although the inflated prices - which caused riots across the globe last year - have stabilised, they remain comparatively high, especially in the developing world.

· World economic crisis is increasing unemployment, reducing remittances that immigrants send back home and making it difficult for poor countries to get credit lines to buy food on the market.

· Thirty countries now require emergency food assistance, including 20 in Africa. FAO (Food and Agriculture Organization) announced in June that the number of hungry people had reached 1 billion, or one in six of the world's population. The world's most populous region, Asia and the Pacific, has the largest number of hungry people - 642 million - followed by Sub-Saharan Africa with 265 million.

What should be done?
· More investments will be needed to fulfil pledges like the UN Millennium Development Goals, which aim to halve of the number of those living in hunger and poverty by 2015. In July, Group of Eight summit in L'Aquila, Italy agreed to raise US$20 billion (S$28 billion) to help farmers in poor countries produce more - a shift from previous emphasis on delivering food aid.

· FAO, which will host a world food summit next month, says global food output will have to increase by 70 per cent to feed a projected population of 9.1 billion in 2050. To achieve that, poor countries will need US$44 billion yearly of aid to agriculture, compared with the current $7.9 billion, to increase access to irrigation systems, modern machinery, as well as to build roads and train farmers.

I was discussing the above topic with my colleague today and can't help but recall the time I brought a group of students to Tanjung Karang in 2004 - a piece of land reclaimed for rice cultivation near to KL, Malaysia.

Much of the production here is a result of government intervention, from reclaiming the land, setting up the irrigation system, providing loans to the farmers, setting up of cooperatives which loan out the combine harvestor as well as selling seeds to the farmers and the gurantee of minimum price for the padi.

Tg Karang Padi Field
40% of the land is reclaimed from peat swamp. Harvesting is done using the combine harvestor which can be loaned from the co-operatives at 40 Ringgits. By tapping on the water from River Tengi and River Bernam, water is available all year round and double cropping is possible. Each individual plot of land is around 1.2 hectares. The water had been drained away from the field through PVC pipes connected to the canal a month before harvesting - that's why we are not wet even though we are standing right in the middle of the field! Sluice gate controls the flow of water into the irrigation system in the rice field. You can see houses for Owl as owls are used as the biological control of pests in the rice fields. nd used for rice production.
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We also went to the rice mill to see how the rice is processed. Mr Hashan and Mr Rosli from the mill explained how the rice is processed in the mill. The moisture content of the rice grain is checked before they are processed and then the husk is separated from the grains. The rice grains are then polished and stored in the huge Silos.

After removing the husk, the brown rice is polished. The powder (bran) is sold as animal feed. The rice grains are further polished and graded before packaging.

The husk are incinerated to ash- which can be used as fertilizers.

Felt the tremor on the 30th Sept 2009 and was shocked at the extent of the earthquake as I am just living on the 6th floor. I realised that it was a 7.6 earthquake from Padang, Indonesia.

One cannot help but think about how natural disasters might affect Singapore. I suddenly recalled the following article on natural disaster - a special edition for Earth Day written by Keith Emuang:

MOTHER NATURE'S FURY
Singapore's geographical location has spared us from many natural disasters. In this special Earth Day (March 20) report, we ask why is this so? By KEITH EMUANG.

Living on an island, it is only natural for us to occasionally wonder how susceptible we are to natural occurring events like earthquakes, tsunamis and rising sea levels. Factors such as the lack of open spaces and highlands, and high density and high-rise dwelling, also fuel our concern.
The good news is that, based on recorded history, Singapore in a geological sense, has been spared from earthquakes and tsunamis. That is however, not to say that we are totally safe or completely free from any type of natural or climatic conditions.

EARTHQUAKE POSSIBILITY?

Studying an earthquake in the hope of anticipating one, involves the tedious seismological monitoring of complex tectonic plate behaviour. Presently though, even with sophisticated scientific land-based and satellite equipment, geologists remain unable to pinpoint the time, place and magnitude of an impending earthquake.

Singapore's susceptibility to an earthquake depends on the characteristics of the outermost layer of the earth's crust (lithosphere). This rigid layer is composed of sections called plates that are in constant motion, gliding on the top of the softer rock below. When two plates come together or collide, there is a tremendous stress and strain where they meet, and a boundary is formed. If the stress exceeds the elasticity threshold of the rocks, the plates can rupture, releasing an enormous amount of strain energy (an earthquake).

The subsequent release of seismic waves, heat and sound energy depicts the magnitude or strength of the earthquake. The area above and around this release of energy is usually most affected by the quake. If a landmass is above or near the boundary, tremors will be felt and if the quake is large enough and below water, a tsunami develops.

Fortunately Singapore does not lie on, along or in close proximity to any boundary. We are sandwiched by the Java trench in the west and south, and the Philippine Plate and trench in the east. We lie on the southerly extension of the Eurasian Plate, in what geologistsrefer to as a seismically stable zone, i.e. free from earthquakes.

According to the National Environment Agency (NEA), past data indicates that we have not suffered an earthquake nor been severely affected from any that have occurred in the region. And although tremors have been occasionally felt by high-rise dwellers in specific areas in Singapore, they are fairly weak. Associate Professor of Geography, National University of Singapore, Victor Savage, qualifies,"Although we are fairly safe, we have to recognise that many times, whenever there is a significant earthquake or volcanic eruption in Sumatra, we have felt the underground tremors in some parts of Singapore. This shows that we are not totally safe or removed from the tectonic instability that takes place in Sumatra."
In the interest of the public, the Meteorological Services Division of the NEA has set up a network of seismic sensors around the island to monitor the effects of these earthquakes from western Sumatra. The data is made available to engineers and researchers, while the general public can access this information whenever a tremor incident occurs on the island.

TSUNAMI LIKELIHOOD?
The 2004 Boxing Day Tsunami is one example of what can happen, in a regional sense, should the Indo-Australian and Burma (part of the larger Eurasian Plate) Plates meet. The boundary between these plates had slipped below sea level and the ensuing earthquake 'kicked up' or displaced hundreds of cubic kilometres of water. This generated a massive sea surge or tsunami, which in this particular instance, fanned out across the Indian Ocean.

As is the case with most tsunamis, the up to 700km/h wave speeds drops considerably before reaching coastlines. However, the size and height of the wave can swell enormously upon hitting land. The surging seas can inundate or flood coastal areas and communities lining the ocean, not unlike how the waters of the Indian Ocean had wrecked havoc across many countries sharing its waters.

The Boxing Day killer tsunami had lost much of its energy by the time it reached our shores. The main thrust of these waves was absorbed by the Sumatran landmass. So, in order to reach Singapore, it had to travel down the bottleneck that is the Malacca Straits. That took much of the sting out of the approaching waves. If a similar-type tsunami were to be triggered by an earthquake due to any boundary along the Indo-Australia Plate, we would be protected in a similar way.

The NEA feels that earthquakes in the region are most likely to occur along major fault lines off the outer coasts of Sumatra, Java and the Philippines. Being sheltered by the Indonesia Archipelago in the west and south and the Philippines in the east, it is very unlikely for Singapore to be directly affected by a tsunami.

Associate Professor Savage adds, "The South China Sea is nowhere as deep as the waters in the Indian or PacificOceans. Thus any tsunami generated from violent undersea disturbances such as massive earthquakes, volcanic eruptions or sub-marine landslides from the eastern areas of the region e.g. the Philippines and Japan, is unlikely to achieve great wave speeds or heights. Therefore any impact on Singapore is likely to be diffused, moderated and less damaging.

Backing this theory, former Geography Professor and author, Ooi Jin Bee, wrote in his article Earthquakes: Will They Hit Singapore? "The Krakatoa volcanic eruption of 1883, for example, generated a tsunami 40 metres high which penetrated 11km inland and totally or partially destroyed over 300 settlements along the Sumatran and Java coasts. Its effect on Singapore was, however, negligible.

HAZARDS THAT HIT HOME
Although we are fairly safe, we have to recognise that many times, whenever there is a significant earthquake or volcanic eruption in Sumatra, we have felt the underground tremors in some parts of Singapore.

We can only hope that our geographical location continues to offer us a haven from natural disasters. Also, we cannot afford to slip too deep into our comfort zone because there are still some climatic hazards, perhaps not as catastrophic but nonetheless, events we need to be aware of.

Few of us need reminding how bush fires in Singapore can seriously affect the air conditions here. During the hot season in Jan-Feb this year, it was reported at one stage that as many as six fires a day were breaking out across the island. Air quality was affected in many parts as a result of that. Smoky haze can also come about from forest fires in Sumatra or spewing volcanic ash such as Mount Pinatubo's cataclysmic eruption in 1991. Depending on their intensities and the direction of the winds, Singapore can be affected.

As recently as 1997, the Pollution Standard Index (PSI) had hit an all-time high of 226 (a reading above 100 being unhealthy). Then, raging Sumatran forest fires were to blame and it also proved what a public and health nuisance it can be.

Rising global temperatures due to an accumulation of greenhouse gases tends to worsen the problem. In the past 10 years, our planet has experienced the warmest climate on record with some of the hottest occurring between 1998 and 2004. Dry seasons become hotter and inevitably, the bush fires will increase in response.

These increasing global temperatures have also triggered the meltdown of our ice caps and the gradual peeling away of huge glaciers from the Arctic and Antarctic, thus raising the mean sea level. Experts belief that by 2100, there would be an estimated rise of between 10cm and 90cm in global sea levels.

Associate Professor Wong PohPoh, Department of Geography, National University of Singapore says, "The scientific community at large acknowledges that over the last 200 years, man has contributed much to the climate change or the phenomenon of global warming due mainly to the burning of fossil fuels.

While the impact of a sea level rise on Singapore is unlikely to be severe, areas with low-lying coasts can nonetheless be affected to some extent.

Professor Wong whose area of expertise lies in coasts and beaches, recounts an instance in December 1999 of how extreme high tides moved inland over the East CoastPark (near the Costa Sands Resort). "The seawater flooded the walkways in the front of the resort and stood up to the level of the stone benches and dustbins. Although this is merely a short-term event, it provides a good analogy for what might happen in the long term. This really shows our vulnerability.

MONSOON MAYHEM
As we are also prone to spells of incessant monsoon rains, flooding can and has been a problem. Granted that much has been and continues to be done to drain the heavy rains and waters from high tides, some parts of the island still remain prone to flooding. We only have to look back to as recently as March last year to realise what three days of persistent rains can still cause.

To alleviate the flooding problem, the Public Utilities Board has embarked on an ambitious project to build a barrage across the 350m-wide Marina Channel. This barrage will act as a tidal barrier to keep high tides at bay and also prevent low-lying areas in the city from flooding, especially when heavy rains coincide with high tides.

When completed in 2007, this will also dam up the MarinaBasin to create a reservoir that will turn seawater to freshwater and add to our water supply.

The close proximity to the Equator has provided Singapore with a tropical climate. However, the characteristic hot and humid weather conditions promote the development of lightning-producing thunderclouds. Based on figures posted on the NEA's website, Singapore experiences an average of 171 thunderstorm days annually. The lightning activity is also high. In fact, Singapore is one of the most lightning prone areas in the world.

Although most times lightning strikes the ground harmlessly, its destructive power is enormous. It can ignite forest fires, destroy trees, damage electronic equipment and disrupt electrical power and telecommunication systems. It is also a hazard to humans.

Most lightning deaths in Singapore occur in the months of April and November, coinciding with the heaviest thunderstorm months. The victims were often in open areas such as the sea, beaches or football fields. For deaths in sheltered areas, victims were often found under a hut, a shed or tree.

Between 2000-2003, lightning fatalities in Singapore averaged 0.35 deaths per million population. The authorities have done a lot to ensure that buildings, highways and other critical infrastructure, is protected from lightning strikes. The rest really depends on the precautions one takes, and Mother Nature.

ABOUT EARTH DAY
Singapore will be observing Earth Day on March 20.
The first Earth Day was officially observed in San Francisco on March 21 1970. The day was chosen to coincide with the Vernal Equinox, the moment when night and day are equal throughout the Earth.

This was symbolic and helped to remind of the Earth's wondrous system of balance, one that mankind is responsible for partially disrupting. It serves as a reminder for us to work to restore it.

Today, Earth Day is observed across the world in a variety of ways including events such as Car-Free Day, Tree-Planting Day, Beach Clean-Up Day, etc. It is a day to celebrate the wonders of our planet and re-instil the important need to care for and protect our natural environment not only for the present generation to enjoy but also for many generations to come.

GLOSSARY OF TERMS
* Vernal Equinox - spring Equinox around March 20
* Tectonic - the earth's crust and what happens within it
* Seismic - earthquakes and other vibrations of the earth
* Submarine landslides - underwater landslides
* Glaciers - slow moving rivers of compacted ice coming down mountains

GO GREEN TO CELEBRATE EARTH DAY
The upcoming International Earth Day offers us the opportunity to kick-start our weakened resolve and commitment towards the 'Green Revolution'.
Recycling and conservation are powerful tools mankind can employ to arrest the indecent rate at which we are stripping Earth of her resources. In Singapore, some doubt what a small nation like ours can do. And even those who are willing, sometimes find things that seem to work against their 'green' endeavours.

Hougang resident Clara Heng says "There used to be special wire bins for cans, paper and plastic products in my neighbourhood. My family would religiously do our bit twice a week. Then after six months, for some reason, the bins were taken away."

Mr Tan EkLeng, a Tampines resident says "People would throw anything in the bins. It was utterly discouraging." But Mr Tan feels that with sustained public education, people will get into the swing of things.

Alicia Raj, a 22-year old private student from Bedok encountered problems with recycling. She says "How are we supposed to dispose of old newspapers when some garang-gunis don't accept them these days? They only want old televisions, radios and computers! Many people I know want to be environmentally friendly but they always hit a snag and are forced to dispose of recyclable materials improperly." Ms Raj is aware of recycling bins near the Bedok Central area but without a car, it is too inconvenient for her family members to take a feeder bus to dispose of their recyclables.

SMALL ROLE, BIG IMPACTThe combined efforts of individuals and the community can do a lot to upkeep the planet's wellbeing. Experts say all that really needs to be done is for everyone to take care of their immediate surroundings, manage their lifestyles along environmentally-friendly lines and get children actively involved.

The cumulative effect of simple tasks like cutting down electricity and water usage, consuming food in environmentally friendly packages and walking over short distances instead of driving will have a big impact on the environment.

Buy green products, especially detergents, soaps and cosmetics, and be on the look out for products that make use of recycled materials. You might also consider doing your marketing using a carrier or basket to save on the number of non-biodegradable plastic bags that you end up taking home.

At the end of the day, it's really a matter of how serious and committed we are in ensuring that our world will thrive. Temperamental as Mother Nature may be, she is the guardian to our beloved planet.