DISASTERS AND MEGACITIES: CRITICAL GEOGRAPHIES OF FLOOD 

HAZARDS & SOCIAL INEQUITIES IN THE CASE OF METRO MANILA

Doracie

B. Zoleta‐Nantes, PhDResearch Fellow and Convener of Master of Natural Hazards 

Resource Management in Asia‐Pacific ProgramCrawford School, College of Asia and the Pacific

The Australian National University

This seminar will address the following  concerns:

• Are big cities becoming more hazardous? 

• How do environmental processes and change influence the geography of risk and 

vulnerability in megacities?

• How have Metro Manila’s uneven development and formation of ethnic enclaves 

with different economic opportunities and political capacity contributed to the 

degradation of its environmental landscapes and marginalization of some cultural 

groups? 

• How have decades of inappropriate planning and poor management of 

infrastructure development programs in the megacity contributed to the scale of 

the September 2009 flood disaster that was triggered by Typhoon Ondoy

(also 

known as Tropical Storm Ketsana)?

• What creative approaches and effective solutions can be undertaken to reduce 

the increasing propensity of Metro Manila to hazardous flooding and mitigate its 

impacts among the most vulnerable groups? 

Urbanisation

• the expansion of urban areas

• increasing concentration of people in urban centers due to natural increase in population and 

migration of people from rural areas to city centers.

• In 1804, there were about I billion people; only 3% of this total lived in cities

• In 1999, there were about 6 billion people; 47% of the total lived in urban centers

• the world's urban population will double every 38 years. 

• By 2030 The UN forecasts that the urban population will rise to nearly 5 billion, or three out of 

five people will be in cities 

• Sources:• http://www.un.org/esa/population/publications/popnews/Newsltr_87.pdf• http://www.census.gov/ipc/www/idb/worldpopinfo.php• http://en.wikipedia.org/wiki/File:Urbanized_population_2006.png

Some definitions

• Hazard

‐the intrinsic unavoidable natural occurrence of something that may 

cause adversities

• Risk ‐

combination of the probability of an event and its negative 

consequences; hazard X elements at risk X vulnerability

• Vulnerability ‐

characteristics and circumstances that make a community, 

system, or asset susceptible to the damaging effects of a hazard

• Disaster ‐

A serious disruption of the functioning of a community or a society …

which exceeds their ability to cope using its own resources

• Mitigation

‐

lessening or limitation of the adverse impacts of hazards and 

related disasters

Source:• United Nation’s International Disaster Strategy for Disaster Reduction

The co‐evolution of risk  and urbanisation

• Urbanization ‐

a mode of human 

organization  that produces new 

relationships and interfaces between the 

built and natural environments in 

population centres 

• Urban systems served as refuge centres for 

people affected by disasters in rural areas   

before 

• As cities expand, more raw materials are 

drawn from the surrounding hinterlands

• Raw materials are turned into products 

(goods and services, social and biological 

reproduction, power) and waste (Pelling

2003). 

• The concentration of waste products and 

congestion of human population 

contribute to environmental degradation 

and increasing susceptibility of places and 

people to environmental risks

Environmental risks in  urban areas

• The construction of  a ‘second nature’

‐

where human intervention had 

created an increasingly modified 

natural world leaving few if any 

elements of it in pristine state (Smith 

1984)  ‐

increases environmental risks.

• Environmental risks

–

consist of 

catastrophic shocks (flooding, 

cyclones, earthquakes, etc) and 

chronic  events  (everyday hazards 

such as poor sanitation, unsafe 

shelter, polluted air) 

• Catastrophic shocks

– more visible; 

studied by disaster specialists

• Chronic events

–

common place but 

less visible; less newsworthy; 

analysed by engineers, social workers, 

land‐use planners, etc. 

Catastrophes and  chronic hazards

• Daily exposure to chronic risks 

reduces people’s willingness to 

prepare for the possibility of 

catastrophic disaster

• Catastrophic shocks lower 

community and household 

resilience to chronic risks and other 

hazard events.

• Greater losses that follow are from 

health risks due to lack of clean 

drinking water, food, sanitation, 

shelter and social order

• Continued exposure to 

environmental risks reduces one’s 

resources and capability to recover 

from future shocks and stresses

• The rachet

effect of vulnerability 

(Chambers 1999) increases as urban 

centres magnify in size. 

Megacities and disasters

• A megacity is a large population center consisting of a metropolitan area, 

or a conurbation of two metropolitan areas and its adjacent zone

of 

influence

• It has a population in excess of 8 million (Nichols, 1995) to 10

million  

(Hardoy, Mitlin

and Satterthwaite, 1992).

• It is synonymous with the term megalopolis

• At the start of the 21st

century, there were 18 megacities 

• Megacities increasingly become the locus of risks (Mitchell 1999) 

• Occurrence of catastrophic and chronic risks become a predominant 

feature of megacities

Why do 

residents of 

megacities seem 

to have an 

increasing 

propensity to 

suffer more from 

environmental 

risks?

• Growth in urban disaster is due to the rapid spatial 

expansion of cities and increase in the proportion of 

national population residing in urban areas at risk 

from many types of disasters (Pelling

2003)

• In 2000, more than 50% of the world population 

reside in urban areas

• In the next two decades, 90% of population growth 

in developing countries will take place in urban 

settlements (Clark 2000, Hilderbrand, 2001)

• Increased population pressure, due to natural 

increase and migration, is linked causally to 

environmental degradation;  this contributes to an 

increase in environmental risks

• The urban poor mostly originate from rural areas 

who lack familiarity to the hazardousness of the 

new settlement sites, access to safe housing, full 

source of employment, social capital and social 

network

Why do megacities  have an increasing  propensity to 

environmental risks?

• Human society overly utilizes the natural 

environment In urban development 

• Increased concentration of infrastructures, 

energy and resources makes megacities more 

vulnerable to catastrophic shocks

• The fragmentation of localized disaster 

experiences due to its areal extent contributes 

to lack of hazard data bases  among populations 

at risk

Mitigation of disasters at the local scale leads to  the 

diversion of the problem to adjoining places

Urban poor have limited access to subsistence food 

production

Rapid colonization of different marginal areas by 

migrants make the production of urban risk 

maps and planning of urban infrastructures 

more difficult

Corruption in governance can be a pressing issue

Table 1: Major cities at risk from disasters

City or conurbation Population 1990 (millions) Population 2015 (millions) Major environmental risks

Mexico City 15.1 19.2 Earthquake, pollution, 

subsidence, drought

Tokyo‐Yokohama 15.3 26.4 Earthquake

Los Angeles 15.3 14.1 Earthquake, pollution

Buenos Aires 11.4 14.1 Flood 

Calcutta 11.0 17.3 Cyclone, flood, human waste

Sao Paulo 9.8 20.4 Flood, pollution

Jakarta 9.1 17.3 Earthquake, volcano, 

salination

of aquifer, human 

waste, flood 

Manila 8.5 14.8 Flood, typhoon

Delhi 8.4 16.8 Flood, human waste

Shanghai* 8.2 14.6 Flood, typhoon

Beijing 7.3 12.3 Earthquake

Cairo* 6.8 13.8 Flood, earthquake

Rio de Janeiro 5.6 11.9 Landslide, flood

Dhaka* 3.4 21.1 Flood, cyclone, human waste

*At risk from sea-level riseSources: Blaikie et al (1994), United Nationas Social Statistics Office un.org/Depts/unsd/social/main.htmal, UNDP World Population Prospects: The 1999 Revision, Kreimer and Munash=inghe (1992)

The case of Metro Manila,  the Philippines

• Uneven regional 

development 

• Formation of ethnic 

enclaves

• Degradation of 

environmental landscapes 

• Marginalisation of cultural 

groups

• Increasing propensity to 

flood hazards

Colonial vestiges of Metro Manila’s urbanization• The Spanish colonials, in built the fort 

city of Intramuros

‐

“inside the walls”

–

and made it the seat of the colonial 

government in 1571

• Manila became the hub for port, railway 

and road networks and was incorporated 

into the global economy

The United States of America invaded Manila 

in 1898

It bought the Philippines from Spain for 20 

million US dollars under the Treaty of 

Paris

• Manila was made the seat of colonial 

government

• The Americans housed its imperialist 

government in Manila and integrated it 

further into the global economy.

http://www.aenet.org/manila-expo/page12.htm

The Treaty of Paris, signed on 3 September 1783, ratified by the the Congress of the Confederation on 14 January 1784 and by the King of Great Britain on 9 April 1784 (the ratification documents were exchanged in Paris on 12 May 1784), formally ended the American Revolutionary War between the Kingdom of Great Britain and the United States of America which had rebelled against British rule.

• On May 29, 1976 

(through PD 940), Metro 

Manila became the 

Philippines’

National 

Capital Region.

• An urban conurbation in 

Asia. 

• 16 autonomous cities and 

one municipality.  

• Land area of 63, 600 

hectares is densely 

settled

• Depends on resources 

coming from nearby 

spaces and all other 

places for its daily 

operations and existence

Metro Manila is the economic and cultural centre of  the Philippines

http://en.wikipilipinas.org/index.php?title=Metro_Manila

http://en.wikipe dia.org/wiki/Fil e:SM_Mall_of_ Asia_wide_pan .jpg

70% of poor Filipinos live in the rural areas

The region with the highest percentage of poor families are:

ARMM (67.3 per cent); Bicol (61 per cent); and Central Mindanao (56.1 per cent.

Four ARMM provinces are among the top ten poorest provinces in the country (FIES 2000).

The average family income among urban residents is PHP 204,977 (AUD 4960.44) while it is PHP 85,373 (AUD 2066.03) among rural residents.

The Philippines

The Philippines

35.79 million persons are in the labor force; 35.8% is employed in agriculture in 2004; 46 % in 1990.

• Philippine Agriculture contributes 18.7% of the total GDP in 2006.

• Top export products are coconut oil (Netherlands and USA), banana (Japan), and pineapple (USA).

Photographs of the Philippine Department of Agriculture

A typical farming system consists of a major crop and a few livestock such as pigs and poultry, with rice, corn and coconut as composite crops.

A good mixture of small, medium and large farms, owned and managed by single families.

From about 3.6 hectares in the 1960s and 1970s, the average farm size declined to 2.8 hectares in the 1990s (Ravago and Cruz 2004)

• From 1993 to 2003, the growth in 

agriculture averages at 1.1 %.

– The Department of Agriculture was 

optimistic in its projection in 2006 that 

by 2007 the growth rate will be 4.5 %. 

– It was not realized.

• The slow growth pace is due to the 

following reasons: 

– slow rate of use intensification and 

expansion in areas under cultivation; 

– high costs of doing business in the 

countryside due to poor infrastructure, 

– lack of research and development 

initiatives, 

– Lack of support on land distribution and 

increased agricultural production

– lack of extension, information and 

education, and 

– poor governance.  

The Filipino farmers in the Cordillera Autonomous Region, Eastern Visayas, and Autonomous Region of Muslim Mindanao, were not given much development assistance by the government.

Many agricultural policies do not address the farmers’ needs.

Thousands of people living in rural areas migrate to Metro Manila due to:

lack of job opportunities in the countryside.the construction boom and establishment of export processing zones in the megacityIts infrastructures and transport systems, andNatural calamities such as drought and typhoons in rural areas.

There is a big difference in the conditions in Metro Manila and other places in the 

Philippine countryside.

The overconcentration of development infrastructure, utilities and services in the 

business districts of Metro Manila is matched by a scarcity of sufficient transport 

systems and development infrastructures in rural Philippines. 

Economic primacyRate of urbanization in the Philippines was:

30 % in 1960; 54% in 1995; and

61 % by 2010.

Over 12 million residents; 14 % of the country’s total population.

In 2007, it generated 33 % of the country’s Gross Domestic Product (GDP) – PhP 2.479 billion or AUD 59.99 million.

Industrial and manufacturing activities are concentrated in the NCR

• The National Statistical Coordinating 

Board of the National Statistics 

Office (NSCB‐NSO, 2008) posted that 

the Philippine population was 

growing at an annual rate of 2.36 %.  

• In 1903, the NCR’s population 

comprised 4 % of the country’s 

population (328,939 out of 7.6 

million). 

• As of 2007, Metro Manila’s 11.55 

million residents comprised 13 % of 

the 88.5 million Filipinos 

• As of 2010, the estimate is Metro 

Manila has over 14 million people

• Metro Manila covers only 0.21 % of 

the country’s total land area of 300, 

000 square kilometers.

The Rise in Population and Competition Over Marginal Living Spaces

Table 2: Percentage share of the National Capital Region on the total population of the Philippines from 1903‐

2007. 

Source: National Statistical Coordination Board, National Statistics Office, 2008.

Year Philippines NCR Percentage

1903 7,635,426 328,939 4.31

1918 10,314,310 461,166 4.47

1939 16,000,303 993,889 6.21

1948 19,234,182 1,569,128 8.16

1960 27,087,685 2,462,488 9.09

1970 36,684,486 3,966,695 10.81

1975 42,070,660 4,970,006 11.81

1980 48,098,460 5,925,884 12.32

1990 60,703,206 7,948,392 13.09

1995 68,615,706 9,454,040 13.78

2000 76,504,077 9,932,560 12.98

2007 88,574,614 11,553,427 13.04

Table 3: Land area and total population of the 17 local government units (LGU) of Metro Manila, 2007.

Source: National Statistical Coordination Board, National Statistics Office, 2008.

NCR cities Land area (sq km)

Population Population density Year the LGU became a city

National Capital Region

636.00 11,553,427 18,166

City of Manila 38.30 1,660,714 43,361 1572City of Mandaluyong

26.00 305,576 11,753 1994

City of Marikina 38.90 426,610 10,967 1996City of Pasig 13.00 617,301 47,485 1997City of Quezon 166.20 2,679,450 16,122 1939City of San Juan 5.94 125,338 21,101 2007City of Calookan 53.33 1,378,856 25,855 1962City of Malabon 23.04 363,681 15,785 2001City of Navotas 10.77 245,344 22,780 2007City of Valenzuela 47.00 568,928 12,104 1998City of Las Piñas 41.50 532,330 12,827 1997City of Makati 27.36 510,383 18,564 1995City of Muntinlupa 46.70 452,943 9,698 1995

City of Parañaque 38.30 552,660 14,430 1998City of Pasay 13.90 403,064 28,997 1947City of Taguig 33.70 613,343 18,200 2004Pateros 2.10 61,940 29,495 Not a city

Many migrants to Metro Manila are either, 

under‐employed, unemployed, or 

underpaid and thus, unable to get decent 

homes.  

38 % of the country’s poor live in urban areas

22% of the urban population is poor 

9.57 million urban dwellers were below the 

poverty level

• They compete for minute living spaces in 

the metropolis, with appalling conditions, 

vulnerable to health, social and 

environmental risks. 

• Millions reside in spaces without 

sewerage facilities, such as in shanties 

built on pavements of side streets, open 

areas beside railways, and covered spaces 

under concrete bridges. 

• 3.56 million urban dwellers lack sanitation 

coverage

• Source: USAUD

Table 4:  Annual Per Capita Poverty Thresholds, Minimum living wage and family living 

wage in the Philippines, the ARMM  and the NCR, 2007 and 2008

All areas Urban  Rural

Philippines

1 PHP

=

0.0242 AUD

PHP    14,866 

AUD

359.757

PHP

16,936 

AUD

409.85

PHP    14,103 

AUD

341.292

Metro Manila

Min wage: PHP  382.00 

(Jan 4 2008)  AUD  9.24

Family Living wage (5 

members):

PHP  917 

AUD  22.19 

PHP    19,345 

AUD

468.149

PHP    19,345 

AUD   

425.59

Autonomous Region of 

Muslim Mindanao

Min wage: PHP  200 

AUD  4.84

PHP    14,845 

AUD  359.249

PHP    16,436 

AUD    361.59

PHP    14,410 

AUD   

348.72

Sources: www.nscb.gov.ph; http://www.nwpc.dole.gov.ph/rtwpb.html; Ibon Foundation

Chronic environmental problem:

• In 2010, there are over 12 

million people in Metro Manila

• A person generates 0.419 kg. of 

garbage a day

• 5.03 million kilograms of solid 

and organic wastes –

daily 

generation of rubbish

• Only 75 % of the solid waste 

that is generated is collected 

daily

• The remaining 1, 260 tons of 

uncollected solid waste is left 

to rot on vacant corners or 

storm drains and other 

waterways.

Metro Manila has five major rivers :

– the rivers of Pasig, Marikina, Paranaque‐

Zapote, Malabon‐Tullahan‐Tenejeros

River and San Juan.

It has two minor waterways –– the rivers of Pateros‐Taguig

and the 

Napindan. 

All seven rivers flow towards Manila Bay. 

Lack of environmental pollution control and 

abatement systems on waste disposal among 

industries and households has transformed the 

river systems into sewage and industrial 

effluent storage areas. 

• A recent trend is the 

mushrooming of houses 

on stilts in the mouths of 

river systems and along 

shallow waterways.

• These squatter colonies 

are highly‐prone to fire, 

flood and health hazards. 

• These derelict urban 

landscapes are not likely 

to disappear in the near 

future. 

Spatial concentration of 

wealth and socio‐political 

privileges: The Makati Central 

Business District and Manila 

Chinatown

Another trend in Metro Manila is the increasing exclusivity of affluent enclaves.

The Chinese Filipinos’ success in trading and manufacturing had some roots in the mid-16th century Philippines

http://www.chinatownology.com/chinatown_manil a.html

They enjoyed the support of the Spaniards in undertaking their trading activities.Manila Chinatown is a culturally distinct enclave.

It has established relations with financial centers in Southeast and East Asia and in the western and eastern coasts of the United States of America, Canada and Australia.

Chinese Filipino residents assert their rights for political representation in these spaces.

They control the political machineries that decide on the provision of infrastructures to support the competitiveness of their financial and cultural enclaves.

Makati : the country’s Central 

Business District (CBD).  

It occupies only 15 % of the total land area of Makati 

City. 

It has 3 million SQM of prime office spaces which 

house half of the nation’s international and 

domestic commercial activities.  

Income from licensing business activities and 

payment of real property taxes in the Makati CBD 

make up the fiscal revenue of Makati City.  

It was PhP

6.6 billion pesos (159.7 million AUD)  in 

2003.  

It houses the national headquarters or offices of 40% 

of the top 1,000 corporations in the Philippines  

The city revenues are spent to further improve its 

world‐class physical infrastructures and 

communication, transport and other services and 

utilities.  

• Adjacent to the Makati CBD are the wealthiest 

neighborhoods in the country where access is 

restricted by providers of security services. 

• They have considerable control over financial 

resources allocation of the country. 

• To support their interests, they wield the 

decision‐making in economic and political 

machineries of the nation.  

• They can improve the physical, cultural, social, 

economic, and political infrastructures in their 

living spaces with the use of government or 

their own personal resources. 

• The experiences of wealthy neighborhoods 

adjoining financial districts are the opposite of 

those in  economically‐deprived spaces, such 

as the Muslim Filipino enclaves.

Historical conflicts and Socio‐economic Circumstances in Muslim 

Filipino Enclaves: A case of group marginalization

• The district of Quiapo, Manila, has been 

the home of the Muslims even before 

Spanish colonization

• The Muslim Filipino enclave in Quiapo

expands steadily.  

• Salah

Jubair(1999) and Abraham Sakili

(2003) chronicled that the struggle of 

the Muslim Filipinos for self‐

determination started in 1565.

• The violence in Mindanao exacerbated 

at the end of the 20th

century.  

• This was due to the entry of multi‐

national corporations (MNCs) that 

benefited from the privatization, 

liberalization and industrialization 

programs of the government.

• The land grabbing of their ancestral domain 

systematically displaced the Muslim Filipinos of the 

ARMM. 

• The Muslim people comprised more than three‐

fourths of the Mindanao population at the time of 

the 1903 census (250,000 out of 327,741). 

• In 1990 the Muslims only accounted for less than 

one‐fifth of the Mindanao population (2,690,456 

out of 14,269,736)

http://morolaw.blogspot.com/

Thousands of displaced Filipino Muslims live a miserable life in shelter camps over the fighting between

government troops and MILF. (Google) http://www.islamonline.net/servlet/Satellite?c=Article_C&cid=12521881

96266&pagename=Zone-English-News/NWELayout#ixzz0hUBiaaf8

Table 5: Estimated Moro and non‐Moro population in Mindanao 1903‐1990 (Selected years)

Source: Jubair, Salah. Bangsamoro: A Nation Under Endless Tyranny. 1999

Year Moro population Non-Moro population

Total Mindanao Population

% share of Moro population

% share of non- Moro population

1903 250,000 77,741 327,741 76.28 23.72

1913 324,816 193,882 518,698 62.62 37.38

1918 358,968 364,687 723,655 49.60 50.40

1939 755,189 1,489,232 2,244,421 33.65 66.35

1948 933,101 2,010,223 2,943,324 31.70 68.30

1960 1,321,060 4,364,967 5,686,027 23.23 76.77

1970 1,669,708 6,294,224 7,963,932 20.97 79.03

1975 1,798,991 7,348,084 9,147,075 19.67 80.33

1980 2,504,332 8,400,911 10,905,243 22.96 77.04

1990 2,690,456 11,579,280 14,269,736 18.85 81.15

• Due to the war and widespread 

underdevelopment in Mindanao 

due to the systematic neglect of 

Mindanao by the central  

government, thousands of Muslim 

Filipinos migrated to other parts 

of the Philippines.  

• About 120,000 Muslim Filipinos 

migrated to Metro Manila

• Muslim Filipino enclaves were 

established in the cities of 

Quezon, Pasay and Taguig.

• Muslim Filipinos have judged that 

the National Capital Region is a 

safer place to live. 

• Health facilities and educational 

opportunities in Metro Manila are 

100X better and more accessible. 

• Muslim Filipino children are not 

exposed to injuries and deaths 

due to perennial exchanges of gun 

fires in the NCR

http://news.bbc.c o.uk/2/hi/asia- pacific/7096069. stm

http://www.collecti velens.com/photo s/photo_12013516 79_b.jpg

• Those with political connections and financial resources integrated in the wealthy enclaves of the 

metropolis.  

• Thousands end up in marginal urban enclaves in Baseco

Tondo, San Andres Bukid, Dakota, and  in certain 

areas in Las Piñas. 

• These urban enclaves are run‐down neighborhoods, which like other places are increasingly more prone to 

flood hazards.

Sitio Baseco, Tondo

http://farm3.static.flickr.com/2611/3738095867_81ec1e7611.jpg

The PHILIPPINES is a hazard- and disaster-prone country. In 2001, 317 disasters devastated the country.

Destruction to properties - PhP 9.223 billion pesos AUD 242.105 million

Typhoon occurrences – average of 19 typhoons a year; 40% or 8 typhoons directly hit the northern Philippines; 6 of which are very destructive

http://upload.wikimedia.org/wikipedia/en/6/6f/Tropical_cyclones_1945_2006_wikicolor.png

Most of Metro Manila lies on semi‐alluvial fans that were formed by the deposition 

of sediments on the eastern shore of Manila Bay by the Malabon‐Tullahan

river 

systems in the north, the Marikina‐Pasig river systems in the east and by the 

Paranaque, Las Pinas

and other rivers in the south.

Thus, many parts of the metropolis are on low‐lying deltaic plains. 

• Flood hazards are 

increasing in 

major urban areas 

due to:

– rapid rate of 

urbanization and

– lack of urban 

planning and 

disaster 

mitigation 

activities.

Metro Manila’s flood hazards and disasters

http://www.selaplana.com/2009/09/26/typhoon-ondoy-floods-manila/

Chronic risks: 

Only 10 % of the drainage facilities in Metro Manila is dredged,

de‐

clogged or maintained each year (14 meters a day).

Most drainage canals are inaccessible due to the encroachment of

squatter communities on waterways’

service roads.

Indiscriminate waste disposal seriously clogs the storm drainage

canals 

and waterways.

Rapid expansion of built-up areas in formerly marsh lands

Increasing number of reclamation areas

Deforestation and other land use changes in NCR’s watershed areas

Increased surface runoff anderosion of topsoil in devegetated watershed areas

Sedimentation and siltation of major river systems

Land subsidence due to groundwater extraction

Changes in groundwater hydrology

Intensification of weather 

events, such as tropical 

storms due to the 

changing climate 

patterns

• Deterioration and poor 

maintenance of flood 

infrastructure

• System failures of flood 

control due to garbage 

and other debris

• Lack of funding to 

maintain flood control 

system

• Lack of disaster 

mitigation programs at 

the local, regional and 

national scales

Effective Flood Control Operations System (for Metro-Manila & Rizal province) was discontinued after it was turned over to MMDA

Flooded areas in Metro Manila from the 1950s to the 1990s

Source:

(Zoleta‐Nantes, 2000)

1950s 1960s 1970s

1980s1990s

Due to the earlier cited reasons, the areas that are affected by floods in Metro Manila continue to increase.

Typhoon Ondoy

(Tropical 

Storm Ketsana)According to the Japan Meteorological Agency a  

tropical depression had formed on 

September 23, 2009 at  about 860 km to the 

northwest of Palau 

(ftp://ftp.met.fsu.edu/pub/weather/tropical/

Tokyo/2009092300.RJTD)

The Philippine Atmospheric, Geophysical and 

Astronomical Services Administration

(

PAGASA) monitored the tropical depression, 

named it Ondoy, and classified it as a tropical 

storm on September 25, 2010. 

Ondoy

is the 15th tropical cyclone to enter the 

Philippine Area of Responsibility in 2009.

Japan named it Ketsana

and assigned the 

international code number 0916 on 

September 26, 2009. 

Ketsana/Ondoy

made a landfall before noon of 

September 26, 2009  in the boundary of 

Aurora and Quezon

Ondoy

had moderate winds (maximum winds of 

85 kph

near the center and gustiness of up to 

100 kph)

http://en.wikipedia.org/wiki/Tropical_Storm_Ketsana_(2009)

The rainfall that was brought about by

Ondoy, according to the September 2010 

records of  the Philippine Atmospheric, 

Geophysical and Astronomical Services 

Administration (PAGASA) was the highest 

recorded since the 1960s.

• Progression of rainfall depth:   (recorded by PAGASA from 8 AM 

of September 26, 2009)

• 8 AM to 2 PM (6‐hour duration):     347.5 mm

• 8 AM to 5 PM (9‐hour duration):     413.0 mm

• 8 AM to 8 PM (12‐hour duration):   448.5 mm

12 highest 6-hour maximum rainfall totals (in mm) recorded at the PAGASA Science Garden from 1965- 2005 historical data (ranked from highest to lowest):

1976 294.51992 242.51967 239.72000 215.51970 197.71979 179.31986 176.11972 158.51974 149.41990 143.81973 131.31966 125.1Source: PAGASA

• The rainfall depth of 448.5 mm in 12 hours has an  associated recurrence interval or return period of  100 years based on the rainfall‐duration‐frequency 

curve that was published by PAGASA is shown  below:  (Source: PAGASA and Guillermo Tabios

III, UP‐NHRC)

• At 2:00 PM on September 26, 2009, Ondoy/Ketsana reached Metro Manila and caused widespread flooding 

in the whole metropolis (80%), most especialy  into the following cities: 

– Antipolo, Makati, Malabon, Manila, Marikina, Pasay, Pasig, Quezon, San Juan, Taguig and Valenzuela were heavily 

flooded and soaked with mud.

• Flood depths ranged from 2 feet to 6 feet, while on the shores of Laguna Lake, the floods almost reached 20 

feet.  

• Major roads in Metro Manila, particularly EDSA, C5, Espana, Aurora and 32 other road sections were 

flooded (http://www.gmanews.tv/story/173229/metro‐manila‐25‐provinces‐placed‐under‐state‐of‐

calamity). 

Residents swim towards high ground during flooding caused by Typhoon Ketsana in Cainta Rizal, east of Manila September 27, 2009. (REUTERS/Erik de Castro)

http://www.boston.co m/bigpicture/2009/09/t yphoon_ketsana_ond oy.html?p1=Well_Mos tPop_Emailed7

Schools were closed; 280,000 people were displaced; 464 people were reported dead; thousands were injured

International and domestic flights were cancelled for a day.

Power supply, communication lines and water supply were lost.

Metro Manila residents were warned of apossible outbreak of leptospirosis.

The total damage as of September 28, 2009 was AUD $ 108.7 million.

There were major disruptions in transportation and other community services and utilities.

Residents wait for rescuers at a building during flooding caused by Typhoon Ketsana in Cainta Rizal, east of Manila September 27, 2009. (REUTERS/Erik de Castro)

http://www.boston.com/ bigpicture/2009/09/typh oon_ketsana_ondoy.ht ml?p1=Well_MostPop_ Emailed7

Computation of flood 

discharge at the Marikina 

River in Sto. Nino,  due to 

the rains that were 

brought about by Ondoy*

SWATCH Model computedPeak Flood Discharge = 5770 cu.m./sof Marikina River at Sto

Niño on 26 September 

2009,

based on thePoint Hourly Rainfall at Science Garden, QCSynoptic Station withapplied area reduction factor = 0.6

Source: PAGASA

*Source: PAGASA

Source: Guillermo Tabios III, UP-NHRC

• The cities of Marikina and Pasig and Cainta , Rizal were the most affected in Metro Manila.  

• Floods in some parts of these places were observed to be about 5‐8 meters in depth.   

• The floodwaters which carried mud, garbage, and all sorts of debris were mixed with bunker oil 

which spilled from the Noah’s Paper Mill in Marikina City.  

• These places are where most of the wealthy and middle class residential subdivisions (33) are 

located.  

Residents stand on electric wires to stay on

high ground while others wade in neck-

deep flood waters caused by Typhoon Ketsana in Cainta

Rizal, east of Manila September 27, 2009. (REUTERS/Erik de

Castro) #

http://www.boston.co m/bigpicture/2009/09/ typhoon_ketsana_on doy.html?p1=Well_M ostPop_Emailed7

Flooded areas in Marikina Valley –

9/2009 Typhoon Ondoy

(Ketsana)

• They recorded the highest number of deaths as compared to other cities and municipalities in 

Metro Manila.  

• These places used to be rice lands and swamplands in the 1960s and 1970s, which were widely 

developed into residential subdivisions.  

• These residential subdivisions were surrounded by walls and dikes but they broke down during 

the flooding events.

An aerial picture shows houses destroyed by flooding brought by tropical storm Ketsana in Marikina City, east of the Philippine capital Manila on September 27, 2009. (NOEL CELIS/AFP/Getty Images)

http://www.boston.com/bigp icture/2009/09/typhoon_ket sana_ondoy.html?p1=Well_ MostPop_Emailed7

What lies ahead?• The concentration of infrastructure, energy, utilities, 

economic opportunities, information and people in 

the metropolis will greatly contribute to the rate of 

urbanization and spatial extent of Metro Manila. 

• This will lead to the formation of “Mega Manila”

– an area that will incorporate the adjacent towns 

and cities in the Central Luzon Region (provinces 

of Bulacan, Nueva Ecija

and Pampanga) in the 

northern part of the metropolis, 

– and the CALABARZON (provinces of Cavite, 

Laguna, Batangas, Rizal, and Quezon) and 

MIMAROPA (provinces of Mindoro, 

Marinduque, Romblon, and Palawan) regions in 

the southern portion of Metro Manila.

This has implications on how the megalopolis will 

deal with many environmental challenges such 

as the ones highlighted by Ondoy/Ketsana. 

Mega Manila will contain nearly half of the country’s population.

http://en.wikipilipinas.org/index.php

http://en.wikipilipinas.org/index.php?title=Mega_Manila

• The formation of Mega Manila 

has to take into account Metro 

Manila’s present‐day realities.  

• Further urbanization of Metro 

Manila does not mean 

development for the 

Philippines. 

• If all the ecological ills and  

uneven spatial transformations 

that urbanization bring 

continue to manifest, the 

negative impacts on diverse 

human groups will persist.

• The need to deal with a 

comprehensive set of 

programs which will address 

uneven spatial and social 

development and land‐use and 

environmental planning 

concerns is salient. 

• If Metro Manila gets more 

urbanized and leads to the 

formation of Mega Manila, the 

implications for the future are 

both promising and grim. 

What  needs to 

be done?

• There is a need for:

• More spatially and socially equitable resource allocation 

and regional development

• More initiatives to address the ecological ills and 

environmental consequences of unplanned urbanization

• More resources and attention for incorporating disaster 

reduction programs in development strategies and 

economic development

• Managing the conditions of urban spaces in relation to 

adjoining non‐urban spaces from where resources 

emanate

• Comprehensive land use planning that takes into account 

the  hazardousness of places and vulnerability of 

communities into development goals.

Further readings and references:

• Agoncillo, Teodoro A. 1990. History of the Filipino People. Quezon City: Garotech Publishing.

• Binay, Jejomar C. 2006. Makati. A City for the People. Makati: FCA Printhouse.

• Diokno, Maria Serena and Villegas, Ramon. 1998. ‘The end of the galleon trade’, in Kasaysayan. The Story of the FilipinoPeople, volume 4. Hong Kong: Asia Publishing Company Limited.

• Japan International Cooperation Agency and Metropolitan Manila Development Agency. 1999. The Study on Solid Waste Management for Metro Manila in the Republic of the Philippines. Final Report Supporting Report, Pacific Consultants International Kokusai Kogyo Co., Ltd., Manila: JICA-MMDA.

• Jubair, Salah. 1999. Bangsamoro: A Nation Under endless Tyranny. Kuala Lumpur: IQ Marin Sbn Bhd, 1999.

• National Statistical Coordination Board - National Statistics Office. 2008. Population Figures and Gross Regional Domestic Product at Current Prices of the Philippines. Philippines: National Statistical Coordination Board-National Statistics Office.

• Ohmachi, Tatsuo and Roman, Emerlinda A. 2002. Metro Manila: In Search for a Sustainable Future. Quezon City, Philippines: University of the Philippines Press.

• Sakili, Abraham P. 2003. Space and Identity: Expressions in the Culture, Arts and Society of the Muslims in the Philippines. Quezon City: Asian Center, University of the Philippines.

• Salita, Domingo C. 1974. Geography and Natural Resources of the Philippines. Quezon City: University of the Philippines Press.

• Wikipedia-The Free Encyclopedia. 2008. “Mega Manila.” Retrieved from http://en.wikipedia.org/wiki/Mega_Manila

• Zoleta-Nantes, D. 2000. “Flood landscapes of Metro Manila.” Pp. 35-51, in Pressures of urbanization: Flood control and drainage in Metro Manila, edited by Dr. L. Liongson, Guillermo Tabios and Peter Castro. Quezon City: UP CIDS.

• Zoleta-Nantes, D. 2002. “Differential Impacts of Flood Hazards among the Street children, the Urban Poor and Residents of Wealthy Neighborhood in Metro Manila, Philippines.” Journal of Mitigation and Adaptation Strategies for Global Change, 7(3): 239-266.

• Zoleta-Nantes, D. B. 2010. “Manila, Philippines.” Pp. 483-486 in Encyclopedia of Urban Studies, edited by Ray Hutchison. California: Sage Publications, Inc.