Monthly Mean Rainfall 1,200 1,000 ) 800 600 400 Rainfall (mm 200 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Iba Manila Baguio

Monthly Mean Temperature 35

30 C) o

25

Temperature ( 20

15 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Iba Manila Cabanatuan Baguio

Monthly Mean Relative Humidity 100 ) 90

80

70

60 Relative Humidity (%

50 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Iba Manila Cabanatuan Baguio

Source: JICA Study Team

THE GOVERNMENT OF THE THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.4.1 The Study on Sabo and Flood Control for Western River Basins of in Monthly Meteorological Values in the Regions the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY F-11 JAPAN INTERNATIONAL COOPERATION AGENCY THE DEPARTMENT OFPUBLIC WORKS AND HIGHWAYS The StudyonSaboandFlood Control for Western River Basins ofMountPinatubo N 3,000 2,500

in theRepublicofPhilippines 3,000 THE GOVERNMENT OF THE PHILIPPINES To Santa Cruz

r

e

v 2500 i 2880 R ll Palawig e nn o Scale 'D O 1:250,000

r e iv o R Capas 15 20'N Iba n 3096 uila aq B

Bucao River B al Bamban River 2,500 in B a r qu e South China Sea er iv 3,000 o Rive R r bia 2867 co a S 2,500 4027 3122 4,000 Mt. Pinatubo Angeles Mt. Arayat Pa Ab F-12 5,000 a si a Por c R g ca Maloma River iver P n o Riv tr er Figure 3.4.2 Isohyetal Mapof Annual Rainfall(Year 1995) 5900 ero Ri San Felipe ve r r e iv R er lla 4201 iv re R a 2629 San Fernando San Narciso . Tomas M 2444 LEGEND Sto o M Becuran ap 15 00'N San Marcelino a Municipality in Study Area n u e Major Highway 2310 pe Gum Lak ai River e n R San Antonio iver Catchment 1995 Active Rainfall Gauge

Subic Dinalupihan B Unit: mm a

l

s

i

c

R i v 2347 e r

Subic Bay 3703 Cubi Point Bay

o o 120 00'E 120 20'E o 120 40'E To Metro Manila 2,500 3,000 3,500 3,500 3,000 2,500 C

a

b a t u a r n e

iv R

R i Iba uilan v aq e B r

iver Botolan ak R taw lin Sample 1 Ba Bucao River Malumboy Poonbato U pp Sample 2 Ba er lin B B uc aq ao ue R ro iver R iv er

r ive Kileng R

T anguay R Cabangan i ver

SOUTH CHINA SEA Mount Pinatubo Anon ang Cree k Sample 6 Maloma River Maloma Sample 3

G o ro n go ron Ri San Felipe ver r C ve uadr Ri Sto. Tomas River er ado Riv a ll e r a Sample 5 M San Narciso Santa Fe

Mapanuepe Lake San Rafael San Marcelino Sample 4

San Antonio Castillejos Pam ata wa n R ive Luzon N r Legend Subic Sampling Point Manila Pyroclastic fans SUBIC 0 5 10 kilometers deposits BAY

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.4.3 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Water Quality Sampling Location in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY F-13 0 5km 10km

Scale

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.5.1 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Basin Boundary Map in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY F-14 N

River Bucao

B5

River

B2 B3 Mt. Pinatubo (No Lake) B a l in B a q u e B1 r o 2 R Area (km ) i v Subbasin e Pre-eruption (1977) Post-eruption (2002) r A. Pre-eruption (in 1977) Maraunot 31.1 12.0 Lubao 35.8 50.5 Balin-Baquero 70.9 68.4 Bucao 133.4 142.1 Total 271.2 273.0

N River Bucao

r raunot Rive 0 5km 10km Ma B4

Scale

LEGEND Lubao River River B3 Basin B2 2.4km2 Crater Subbasin Lake

B a lin -B a q B1 u e r o R iv e r B. Post-eruption (in 2002)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.5.2 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Change in Catchment Area in the Bucao in the Republic of the Philippines River System JAPAN INTERNATIONAL COOPERATION AGENCY F-15 Bucao River

Pinatubo Crater Lake

Maloma River

Sto. Tomas River

Scale

Source: JICA Study Team

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.5.3 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Location of Dammed-up Lakes in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

F-16 Bucao River

Pinatubo Crater Lake

Maloma River

Sto. Tomas River

Scale

Source: JICA Study Team

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.5.4 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Volume of Lahar Deposition along River in the Republic of the Philippines Channels JAPAN INTERNATIONAL COOPERATION AGENCY

F-17

iver

ot R ot

un

ra

a

M

River

River Bucao

pper

U Balintawak

Poonbato

ro River

Balin Buque 2 2 2 Malumboy

Source: PHIVOCS, 1994 Source: PHIVOCS,

River

LEGEND: Baquilan 2km N 1 Scale Lahar Deposit Area in 1991 (48.2km ) Lahar Deposit Additional Area in 1992 (3.9 km ) Additional Area in 1993 (4.0 km ) Additional 0

Bucao River Bucao Bridge Botolan

National Highway 7

South China Sea

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.1 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Lahar Deposit Area in the Bucao River in the Republic of the Philippines System JAPAN INTERNATIONAL COOPERATION AGENCY

F-18 Bucao River N

Baquilan River 2km 1 Scale

San Juan

ike

g D g

Road

xistin E Bucao Bridge National Highway

Natio

nal H Botolan

ighw r e

Habitual iv ay

Inundation Area R o

ca Bu

South China Sea

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.2 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in the Republic of the Philippines Habitual Inundation Area along Bucao River JAPAN INTERNATIONAL COOPERATION AGENCY

F-19 0 0.5 1km 20 Scale 100 N Maloma River LEGEND Inundation Area (350ha) (H=1.0m. T=4hrs) (360 houses)

400 20

200 er

iv

R

a Dike Road Dike 200 20 m 0 0 1

Malo

0

0

1

Anonang River k e y 7 re hwa ridge al Hig C ation ub Maloma B N Tic

20 0 10 National Highway 7 ill Tictic H

20 hina Sea South C

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.3 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Inundation Area along the Maloma River in the Republic of the Philippines in August 2001 JAPAN INTERNATIONAL COOPERATION AGENCY

F-20 0 0.5 1km 20 Scale 100 N Maloma River LEGEND Inundation Area (510ha) (90 houses, H=0.5m)

400 20

200

ver

i

R

a Dike Road Dike 200 20 0

lom 0

a 1

M

0

0

1

Anonang River k ay 7 ree ighw C nal H ub Maloma Natio ic T Bridge

20 100 National Highway 7 ll Tictic Hi

20

South China Sea

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.4 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Inundation Area along the Maloma River in the Republic of the Philippines in July 2002 JAPAN INTERNATIONAL COOPERATION AGENCY

F-21 N

0 12

Scale

Mapanuepe Lake

Aglau

arella River arella M Dalanaoan

Mt. Bagang

River

Fe

ta

n a S San Rafael Castillejos San Marcelino 2 2 2 Vega Hill Vega

r

e 1994 Source: PHIVOLCS,

iv LEGEND: s R a

m

. To

to S Additional area in 1992 (6.2km ) Additional Area in 1993 (11.5km ) Additional Lahar Deposit Area in 1991 (55.4 km ) Lahar Deposit

San Narciso ghway 7 National Hi Maculcol Bridge San Antonio

South China Sea

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.5 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in the Republic of the Philippines Lahar Deposit Area in the Sto. Tomas River JAPAN INTERNATIONAL COOPERATION AGENCY System

F-22 LEGEND: Inundation Area due to Dike Breaching

l

il

H ike

g D Vega

N istin Ex 0 12km

Scale

reached

in 2000

B

Existing Dike

d

ver oa i R

Sto. Tomas R

ay

National Highw

O

S

I

C

R

N

A

Maculcol NA S Bridge

LA PAZ

reached

B in 2002

South China Sea

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS Figure 3.6.6 The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo Inundation Area along the Sto. Tomas River in the Republic of the Philippines in 2000 and 2002 JAPAN INTERNATIONAL COOPERATION AGENCY

F-23