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Level 3 Geography

91429

Demonstrate understanding of a given environment(s) through selection and

application of geographic concepts and skills

Resource booklet

Refer to this booklet to answer the questions for Geography 91429.

Check that this booklet has pages 1-8 in the correct order and that none of these pages are blank

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Source A: Location, Size and Extent of Bangkok, Thailand

Bangkok city covers an area of 1,568.737 square kilometres. Of this, about 700 square kilometres form the built-up

urban area.

Satellite Image of Bangkok Metropolis Area

Satellite

image of

Bangkok

Metropolis

area. The

Bangkok city

proper is

highlighted in

this satellite

image of the

lower Chao

Phraya delta.

Bangkok is in the Chao Phraya River delta in Thailand's central plains. The river meanders through the city in a

southward direction, emptying into the Gulf of Thailand approximately 25 kilometres south of the city centre. The

area is flat and low-lying, with an average elevation of 1.5 metres above sea level. Most of the area was originally

swampland, which was gradually drained and irrigated for agriculture via the construction of canals (khlong) which

took place throughout the 16th to 19th centuries. The course of the river as it flows through Bangkok has been

modified by the construction of several shortcut canals.

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Map showing elevation of Bangkok Metropolitan Area

Source B: The Geology of Bangkok Metropolitan Area

The geology of the Bangkok area is characterized by a top layer of soft marine clay known as Bangkok clay, averaging

15 metres in thickness. This Bangkok clay has contributed to the effects of subsidence due to the fact the clay soil is

soft and easily compressible. First recognized in the 1970s, subsidence soon became a critical issue, reaching a rate

of 120 millimetres per year in 1981. Ground water management and mitigation measures have since lessened the

severity of the situation, although subsidence is still occurring at a rate of 10 to 30 millimetres per year, and parts of

the city are now 1 metre below sea level. There are fears that the city may be submerged by 2030. Subsidence has

resulted in increased flood risk, as Bangkok is already prone to flooding due to its low elevation. The Bangkok clay

along with deep well water pumps and urbanisation has increased the rate of subsidence. The clay on which the city

sits needs to retain moisture, otherwise it dries out, becoming more susceptible to subsidence. This results in the

city sinking faster. Groundwater is needed to allow the clay to retain its supportive qualities, but Bangkok’s heavily

concreted urban sprawl prevents it from seeping through to the right areas. Instead, it floods the city or flows

through to rivers and canals, putting further pressure on rising water levels.

Source C: The Climate of Bangkok Metropolitan Area

The climate here is tropical. The summers here have a good deal of rainfall, while the winters have very little. The

average temperature in Bangkok is 28.1 °C. About 1430 mm of precipitation falls annually.

Annual Weather Data for Bangkok Metropolitan Area

January February March April May June July August September October November December

Avg. Temperature (°C)

26 27.5 29.1 30.2 29.7 28.9 28.6 28.3 28 27.9 26.9 25.6

Precipitation / Rainfall (mm)

7 20 24 67 182 156 165 191 320 239 51 8

There is a difference of 313 mm of precipitation between the driest and wettest months. Throughout the year, temperatures vary by 4.6 °C.

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Annual Average of Precipitation in Bangkok Metropolitan Area between 1965 – 2015

Year Annual Precipitation Total (mm) Year Annual Precipitation Total (mm)

1965 1675 1994 2206

1974 1394 2009 2293

1982 1945 2011 2392

1988 2050 2015 2015

Source D: Bangkok Metropolitan Flood Prone Areas

Map showing the areas at risk

of flooding during the 2011

Bangkok Flood.

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Source E: Urbanisation

Risk of flooding in Bangkok has increased due to inadequate drainage infrastructure resulting from rapid

urbanisation. The city now relies on flood barriers and augmenting drainage from canals by pumping and building

drain tunnels, but parts of Bangkok and its suburbs are still regularly affected by flooding. Heavy downpours

resulting in urban runoff meaning the drainage systems, and runoff discharge from upstream areas are unable to

cope. As a result severe flooding affecting much of the city occurred recently in 1995 and 2011. In the latter, most of

Bangkok's northern, eastern and western districts became inundated, in some places for over two months. Global

warming poses further serious risks, and a study by the OECD has estimated that 5.138 million people in Bangkok

may be exposed to coastal flooding by 2070, the seventh highest among the world's port cities.

Population Density in the Bangkok Metropolitan Area.

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Source F: Urban Sprawl

Map showing Urban Sprawl between 1850 – 2002.

Historical census population for Bangkok Metropolitan Area

Year Population Year Population

1919 437,294 1970 3,077,361

1929 713,384 1980 4,697,071

1937 890,453 1990 5,882,411

1947 1,178,881 2000 6,355,144 1960 2,136,435 2010 8,280,925

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Source G: Subsidence of Bangkok and Flooding

Several factors – climate change, rising sea levels, coastal erosion, shifting clay soil – are threatening the great city on

the Chao Phraya delta, founded in 1782. The population has greatly increased, with about 10 million people now

living in the city and its suburbs. Even the weight of the skyscrapers, constantly on the rise due to population change,

is contributing to Bangkok's gradual immersion. Much of the metropolis is now below sea level and the ground is

subsiding by 1.5 to 5cm a year.

In the medium to long term more than 1 million buildings, 90% of which are residential, are under threat from the

rising sea level. In due course the ground floors of buildings could be awash with 10cm of water for part of the year,

according to the Asian Institute of Technology. In the port of Samunt Prakan, about 15 km downstream from the

capital, the residents of detached houses along the river already spend several months a year up to their ankles in

water.

Illegal tapping of groundwater is one of the causes of the capital's misfortunes, according to Jan Bojo, a World Bank

expert based there. Not all the specialists endorse this view, but they do agree the situation is bound to deteriorate

over the next few years. Smith Dharmasaroja, the head of the National Disaster Warning Centre, is predicting that by

2100 Bangkok will have become a new Atlantis. Dharmasaroja's forecasts are being taken seriously: in the 1990s he

predicted the fearful tsunami that devastated countries around the Indian Ocean in 2004.

Dharmasaroja maintains that "no decision has been taken" at government level "to stop the problem". And, he adds,

if nothing is done Bangkok could be underwater by 2030.

One of the solutions he has suggested is to build a series of dykes along the coast of the Gulf of Thailand, a scheme

that would cost over $2bn. He says work should start immediately, otherwise it will be too late to halt the chain of

events leading to disaster. "The rise in sea level is not that great and climate change only plays a fairly small part –

about one-fifth – in the current scenario," he adds. "It's pointless," he stresses, "to try to protect the coastline, which

is being eroded by three to four centimetres a year. But there are plenty of other ways of combating flooding, such

as better management of building land in the city."

Niramon Kulsrisombat, a town planner and lecturer in urban and regional planning at Chulalongkorn University,

confirms that "floods have always occurred, Bangkok having been built on sodden terrain 1.5 metres below sea

level". A network of khlongs (canals), fields and allotments used to soak up flooding, but with recent urbanisation

many buildings have taken their place and the water is trapped. "Government efforts have focused on raising

barriers 2.8 metres high along various stretches of the Chao Phraya," Kulsrisombat explains, "but this has just done

even more damage to the traditional appearance of a settlement where people lived on the water in houses on

stilts."

This subsidence is accelerated by the sheer number, size and weight of all the buildings pressing down on the land all

around Bangkok according to recent research. "There are about 700 buildings with 20 floors or more and 4,000

buildings with 8-20 floors in Bangkok," said Witthaya Kulsomboom, the head of the committee. "There are also many

electric railways. These could cause the submergence of parts of Bangkok and surrounding areas in the future."

Table showing the number of Constructed Residential Buildings (between 12-74 floors)

Year Total Number of Buildings Year Total Number of Buildings

1995 7 2011 3

1996 1 2012 5

1998 1 2013 3 1999 2 2014 4

2006 3 2015 5

2007 3 2016 3

2008 4 2017 7

2009 6 2018 4 (to date)

2010 4

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Source H: Impacts of Flooding on Bangkok in the 2011 Floods

IMPACT ON GDP AND INFLATION

The central bank slashed its 2011 economic growth forecast to 2.6 percent from 4.1 percent on October 28, with the

economy likely to shrink 1.9 percent in the fourth quarter from the previous three months. It said it might review the

forecasts again in November. The cost to the economy could go far higher if Bangkok, which accounts for 41 percent

of GDP, is swamped. The Thai Chamber of Commerce has estimated the flood cost at 250 billion baht ($8.2 billion)

and said it would take about three months for business to recover. Inflation rose to 4.19 percent in October — well

below the 4.5 percent forecast by economists but food prices were almost 10 percent higher than a year before.

IMPACT ON FACTORIES

The floods have forced seven big industrial estates north of Bangkok to close, affected at least 9,859 factories and

660,000 jobs. The electronics and car sectors have suffered; Thailand is a regional hub for the world’s top car

producers, and even if most of the big assembly plants are in the east, away from the floods, car part firms have

been hit. Firm such as Toyota Motor Corp and Honda Motor Co have scaled back production at plants as far away as

North America. Honda, whose assembly plant has been flooded, said this week it did not know when car production

would resume in Thailand. Nissan Motor Co said on Wednesday it might restart production from November 14.

Some tech firms are starting to make plans to reopen in a few weeks, although the picture varies greatly. Stars

Microelectronics (Thailand) Pcl, for example, says it hopes to restart some production lines at its hard drive part

plant at Bang Pa-in estate in Ayutthaya province on December 1. Thailand is the world’s second-biggest maker of

hard disk drives. World prices are rising because of the disruption in Thailand and computer makers such as Lenovo

Group Ltd have said they expect hard drive supply problems through the first quarter of next year.

The Commerce Ministry expects exports to fall 13 percent in the fourth quarter from a year earlier.

RICE, TOURISTS AND BANKS

Thailand is also the world’s biggest rice exporter and the government has estimated that it could lose a quarter of its

main crop due to the floods. Harvesting of the crop began in October and the government says output could be 19

million tonnes of paddy rather than 25 million. Some Thai rice exporters may be obliged to declare financial losses if

the situation gets worse, although none appear to have done so yet.

Tourist arrivals in the fourth quarter are expected to drop as much as 20 percent below the 5 million target at a cost

of about 20-30 billion baht, according to Kongkrit Hirankij, head of the Federation of the Thai Tourism Industry.

Tourism Minister Chumphol Silpa-archa has said arrivals could be up to 1 million below the government’s target of

19 million this year. Don Muang airport, used by budget airlines for domestic flights and by private planes, has been

closed since October 25. The main international airport, Suvarnabhumi, is still open. At least 482 bank branches,

including around 200 in Bangkok, have been forced to close.

Flooding at Don Muang airport

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Sources:

Satellite Image: https://en.wikipedia.org/wiki/Bangkok#/media/File:Bangkok_satellite_city-area.jpg

Phien-wej, N.; Giao, P.H.; Nutalaya, P (2 February 2006). "Land subsidence in Bangkok, Thailand". Engineering

Geology. 82 (4): 187–201. doi:10.1016/j.enggeo.2005.10.004.

https://web.archive.org/web/20071030034936/http://edition.cnn.com/2007/TECH/science/10/22/thailand.water.risi

ng.ap/index.html

https://en.wikipedia.org/wiki/Bangkok

https://en.climate-data.org/location/6313/

https://www.channelnewsasia.com/news/asia/asia-s-future-cities-can-bangkok-turn-back-the-rising-tide-and-s-

7612754

Urban Sprawl Map: https://www.researchgate.net/figure/The-Expansion-of-Bangkok-Thailand-1850-

2002_fig15_267418628

http://www.thaitravelblogs.com/2011/10/map-of-flood-risk-areas-in-bangkok/

https://journals.openedition.org/netcom/docannexe/image/2725/img-1-small580.jpg

https://www.theguardian.com/environment/2011/sep/06/bangkok-thailand-risks-steadily-sinking

https://www.reuters.com/article/us-thailand-foods-factbox/factbox-thailands-flood-crisis-and-the-economy-

idUSTRE7A11BC20111102

https://wordlesstech.com/worst-flooding-in-thailands-history/

https://en.tutiempo.net/climate/ws-484550.html

https://weather.com/science/environment/news/bangkok-sinking-subsidence-warming-15-years

http://www.skyscrapercenter.com/quick-lists#q=&page=1&type=building&type=tower&type=supported-

tower&status=COM&functions_concatenated=residential&min_year=1885&max_year=2018&region=0&country=0&c

ity=1471