Professor Josefina Natividad

The Demographic Consequences
of the Mt. Pinatubo Eruption: A
Comparison of Two Towns in
Central Luzon
Josefina N. Natividad
Population Institute
University of the Philippines
What the literature says…
“Demographic factors such as population growth, composition
and distribution are perhaps the most important factors that
have increased vulnerability to disasters” (Donner and
Rodriguez, 2008)
“Poverty influences nearly all stages of the disaster process including risk perception, preparedness, warning
communication, physical and psychological impacts, emergency
response, recovery, and reconstruction s (Fothergill and Peek,
2004)
“ Socioeconomic inequality is one of the root causes of
vulnerability to disasters (Wisner,et.al., 2004)
“Social resilience is an important component of the
circumstances under which individuals and social groups
adapt to environmental change” ….but social resilience may
be linked to ecological resilience through the dependence on
ecosystems of communities and their economic activities
(Adger, 2000)
Resilience vs. transformation (Pelling, 2013)
Data sources
Philippine census:
1948, 1960, 1970, 1980, 1990, 1995,
2000, 2010
Municipal Land Use Plans of Bacolor and
San Marcelino
Field interviews
Location
http://earthobservatory.nasa.gov/Features/AstronautPinatubo/
Pinatubo
Crater Lake
Mapanuepe
Lake
The Eruption
850 deaths, 932 including deaths in evacuation centers
About 1 million people affected
US$400 million in property damage
The Caldera- Eruption, June 1991
O'Donnell River
April 1991
July 1991
Bucao River
May 28, 1991
May 16, 1994
Case Study 1: Bacolor
Pinatubo
Crater Lake
Mapanuepe
Lake
Intercensal population growth rates of 3 laharaffected towns in Pampanga, 1948-2010
20.00
15.00
10.00
5.00
0.00
1948-1960
1960-1970
1970-1980
1980-1990
1990-2000
Porac
Santa Rita
-5.00
-10.00
-15.00
-20.00
Pampanga
Bacolor
2000-2010
120000
Population size of 3 lahar-affected towns in
Pampanga, 1948-2010
100000
80000
60000
40000
20000
0
1948
1960
Porac
1970
1980
Bacolor
1990
Santa Rita
2000
2010
Barangay Parulog, Bacolor, Pampanga
Aug. 21, 1994
Sept. 22, 1994
Bacolor, Pampanga
Bacolor after the 1995 lahars
Population Density by barangay
1990, 1995, 2000, 2010
San Guillermo Parish Church, Bacolor, Pampanga
August 1899
June 2013
The Mission of the Bacolor municipal
government as posted in the town hall
Conclusions about Bacolor :
•
The magnitude of the effect of lahars burying the town of Bacolor in 610 meters of sand is such that the recovery period may take a very long
time
• The government strategy to contain lahars by building most of the diking
system in Bacolor exposes Bacolor to continuing threats of flooding.
• Being an agricultural economy pre-eruption, the loss of soil fertility
means there are few livelihood opportunities and little incentive for
former residents with economic options elsewhere to return
• There are growing settlements of informal settlers composed mostly of
former tenants
• Bacolor is an old town with a rich history both in pre-Hispanic and
Hispanic times. Town residents bank on this rich historical memory to
lure back old residents through religious festivals, web-based campaigns,
• and other means.
Case Study 2:
San Marcelino, Zambales
Pinatubo
Crater Lake
Mapanuepe
Lake
Intercensal growth rates 1948 to 2010,
Zambales
10.00
5.00
0.00
-5.00
-10.00
-15.00
Zambales
Botolan
San Marcelino
San Narciso
Population size, Zambales municipalities affected
by Pinatubo eruption
200000
150000
100000
50000
0
1948
1960
Botolan
1970
1980
San Marcelino
1990
2000
San Narciso
2010
Population density in high density barangays, 1990-2010
2997
2531
2844
3139
San Isidro
1609
1478
1494
1726
Rizal
1625
1425
1568
1782
LaPaz
1156
995
1094
1547
Consuelo Sur
4972
4328
4122
4006
Central
2110
1995
2163
2275
Burgos
0
500
1990
1000 1500 2000 2500 3000 3500 4000 4500 5000
1995
2000
2010
Population density in medium density barangays, 1990-2010
615
San Guillermo
560
Lucero
683
683
772
317
321
376
442
Linusungan
251
237
301
368
Linasin
170
Laoag
310
245
347
554
519
567
Consuelo Norte
788
150
97
48
59
0
1990
715
776
145
79
112
167
Nagbunga
Buhawen
738
100
200
1995
300
400
2000
500
600
2010
700
800
Population density in low density barangays, 1990-2010
44
15
Santa Fe
18
20
72
36
San Rafael
43
69
31
4
Rabanes
11
28
29
26
26
Aglao
22
0
1990
10
20
1995
30
40
2000
50
60
2010
70
80
Sitio Pili, Barangay Buhawen San Marcelino
Lahar-swamped towns: San Marcelino, Zambales
Santo Tomas Dike
Santo Tomas River Dike, San Marcelino, Zambales
A wider shot of the two areas separated by a dike
Black sand mining
Conclusions about San Marcelino
• The effect of the eruption was largely confined to low density
barangays in the upland areas therefore San Marcelino as a
town did not suffer as catastrophic an effect on its size as
Bacolor.
• While the agricultural land, especially rice land may take a
long time to recover, the damage is in a limited area only.
There are alternatives to rice farming that the farming
population has begun to explore
• Unlike Bacolor, San Marcelino can theoretically internally
absorb even those who were displaced by the eruption
because it has not been as densely populated as Bacolor nor
as uniformly affected
• Like Bacolor, families directly affected by the lahars were
resettled in government-constructed resettlement areas in
other town in Zambales
• Those who can not earn a living in the resettlement areas
have returned and now illegally occupy public lands in San
Marcelino: the land grant of the Western Luzon Agricultural
College and forest land administered by the Department of
Environment and Natural Resources
• The issue in San Marcelino is not one of poor ecological
resilience but of property rights. Rice farmers displaced by
lahars cultivate other crops (bananas, tiger grass, root crops)
in land that they do not own. They have built new villages on
public lands. There is evidence of conflict with authorities
about illegal settlement in these public lands.
CONCLUSIONS:
• Demographic trends give us the broad picture for understanding
the equally broad effects of a disaster
• Community level data give us a more refined picture to
understand the specific effects and the context under which they
arise
• In an agricultural economy, post-disaster resilience of a
community is highly linked to ecological resilience
• Pre-existing conditions of socio-economic inequality tend to
persist and to affect post-disaster rebuilding. In an agricultural
economy, social inequality stems mostly from land tenure issues.
• Resilience or transformation?
The Caldera: Present time