CHAPTER 2 STUDY AREA

trextemperMechanics

Feb 22, 2014 (3 years and 8 months ago)

61 views

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
1

CHAPTER
2

STUDY AREA



2.1

NATURAL CONDITION


2.
1
.1

River System


Pulangi
River

meanders across the provinces of Bukidnon, Davao del Sur, Lanao del
Sur, Maguindanao and North Cotabato

as shown in
Figure 2.1
-
1
. I
ts

main
river
channel
has a total stretch of 353.
20 km.





Figure 2.1
-
1

Pulangi River System

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
2

2.
1
.
2

T
opography

and Drainage

The Mindanao River Basin (MRB)
, which has a total catchment area of 21,502 km
2

is a
large dendritic catchment with substantial volume of water coming from upstream
sections of Pula
ngi (northern section) and Ala Valley (southern section) sub
-
watersheds
.
These waters enter

into the Liga
wasan marsh and eventually flow

into th
e Illana Bay
in
Cotabato City.

The Pulangi River, whi
ch serves as the largest tributary of MRB, drains an
area o
f 4,099 km
2

and

originates
from

the Ce
ntral Cordillera Mountain Range.

It
flows
southwest to the Ligawasan Marsh, where it becomes the Mindanao River and
careens

to

the

west and then northwest.

Among the notable tributaries of the Pulangi River
System in t
he northern highlands are: Maridagao, Mulita, Kulama, Arakan, Kabacan,
Manupali, Calabugao and Tigua Rivers.

The general landforms and topography of
the
Pulangi River Sub
-
basin and other river
systems of

the

northern watershed
s

of
the
Mindanao River are g
enerally dictated by
complex geological events
,

e.g. volcanism, erosion process, sedimentation and probable
minor uplifts. They are primarily the products of constructional volcanic processes
composed largely of lava flows, intrusive rocks, pyroclastic dep
osits and volcanic rocks
and fluvial sediments. The volcanic satellite and slopes
(western headwaters)
of Pulangi
River Sub
-
basin were built from strong and explosive eruptions of pyroclastic debris and
relatively quiet extrusion of lava flows. The lower f
lanks of the pyroclastic rocks are
occupied by unconsolidated laharic deposit, reworked sediments and intercalated
sedimentary rock sequence. Weathered transported deposits filled up the lowland areas
and formed the alluvial plains fringed by river materia
ls along drainage sections and low
hills and knobs
,

as remains from erosion and weathering of old sedimentary rock
sequence in the eastern highlands. Surrounding the volcanic cones of Mt. Musuan
-

520
m amsl and Kalatungan Volcano
-

2379 m amsl
of the basi
n
-

basaltic to andesitic
volcanic flows dominate with minor intercalation of pyroclastic materials.


The Pulangi

River plains immediately embrace the northeastern sloping topography of
the Province of Bukidnon and the rugged terrains of
a
chain of peaks

c
omposed

of Mt.
Katanglad, Mt. Kilakron and Kalatungan Mountains in the northeast. High relief, steep
ridges and banks and dendritic darainage pattern characterize the rugged eastern
highlands. The northeastern tableland is bounded to the east by the Tigua
River and its
southern extension is cut by the western headwaters of Kulaman River and Mulita River
that encompasses the Municipality of Maramag in the Province of Bukidnon. In the west,
the elevations and slopes of the plateau rise up and become rugged as

it cuts the cliff
-
forming chains of limestone belt in the northern part of Cotabato that traverses the
embankments of the southwestern river basin.


Th
e main drainage pattern of Pulangi River in the northeastern quadrant flank of Mt.
Musuan and Kalatungan

volcano (Mt. Kitanglad) generally follows the southern trend
with headwaters of opposite directions (eastern and western).

Radial with minor dendritic
drainage patterns occur in the younger pyroclastic

and sedimentary

areas whereas,
ir
regular networks are

introduced on

relatively hard rock formations
, e.g. limestone belts
and volcanic flows
.
In the eastern highlands, towards the western face of Mt. Apo, the
drainage systems of Arakan and Kabacan Rivers follow the western trend before they
merge with the ma
in flow of the Mindanao River.





Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
3

2.1.3

Geology


The geology of

northern

MRB
, which encompasses the Centr
al Mindanao and Cotabato
Valley,
belong
s

mainly to the Quaternary Volcanic Complex consisting of
the
Lanao
Volcanic Complex, Ragan
g Volcanic Complex
a
nd Musuan Volcano. They are generally
characterized by volcanic flows in their summit and high slope areas with pyroclastic flow
rocks at their flanks and low slope areas. The volcanic flow rocks are composed mainly
of basalt and basaltic andesite with dac
itic influence around the summits. The pyroclastic
rock units consist mainly of pyroclastic flows, ash fall deposits and lahar sediments.
Erosion as the main mechanical weathering in the entire basin produced the recent
deposit and lahar aprons along coast
al plains and gentler slopes

(see
Figure 2
.1
-
2
).



Figure 2.1
-
2

Distribution of Volcanoes in Mindanao River Basin


Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
4

Pantaron Ultramafic Complex (Cretaceous)


Occurs within the Pantaron Range that separates Buk
idnon, Agusan Del Sur and Davao.
T
he dominant
lithology of this unit is peridotite and gabbro and was emplaced probably
during

the Cretaceous period
.


Logawan Diorite (Late Miocene)


This igneous composite body consists mainly of diorite, pyroxenite and gabbro. The
mutual relation among these rock ass
emblages suggests that the emplacement of the
diorite was preceded by the formation of pyroxenite and gabbro.


Malambo Andesite (Pleistocene)


The unit that may be correlated with the andesite flow breccias in Mt. Apo consists
mainly of andesite lava flows

and breccias exposed in the upper reaches of Tigua River.


Koronadal Formation (Pleistocene)


Notably distributed in Koronadal, Allah Valleys and Matutum, the rock formation
comprises the poorly consolidated tuffaceous sandstone and mudstone intercalated
with
lenses of conglomerate, agglomer
ate, basalt and andesite. These

rocks usually occur as
lenticular belts covering the gentle slopes of Mt. Apo, Parker and Matutum and at the
fringes of the Allah and Koronadal Valleys.


Patut Formation


The formation
re
fers to

the sedimentary sequence notably exposed along Patut Creek, a
tributary of Simuay River in western Cotabato. The Dinganen Formation conformably
overlies the formation. The entire formation is subdivided into
two (
2
)

facies: the near
-
shore marine an
d terrestrial beds in the northern part of Cotabato Valley and the offshore
marine Saul Creek facies in the south
-
central part of the valley.


The formation consists of cobble conglomerate and thick
-
bedded coarse
-

to medium
-
grained greywacke with occasiona
l interbeds of carbonaceous mudstone. The
conglomerate is usually massive and occupies the lower part of the sequence. On the
other hand, the Saul Creek facies consist of interbedded siltstone, mudstone and
medium
-
grained sandstone with a basal lenticular
porous reefal limestone.


Dinganen Formation (Late Miocene)


Conformable over the Patut Formation, the formation is commonly exposed in Dinganen
Creek
-
a tributary of Simuay River. It is composed of blue to gray mudstone, claystone
and tuffaceous sandstone.

The type of locality in south
-
central and northern part, which
is affiliated to marine condition/environment, the formation is dominantly mudstone and
claystone.


In the southern part, the formation becomes non
-
marine
consisting

mainly of
conglomeratic pa
tches and lenses of boulder conglomerate.




Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
5

Nicaon Formation (Late Miocene
-
Pleistocene)


The Nicaon Formation, which is dominantly composed of marine clastic rocks, is divided
into a lower finer clastic member and an upper coarse clastic member. The lower

member is made up of interbeds of blue
-
gray fossiliferous mudstone, tuffaceous
sandstone, siltstone, pebble conglomerate and agglomerate with minor intercalations of
limestone and marl. The upper member includes the non
-
marine conglomerate, cross
-
bedded s
andstone with minor intercalations of sandstone and siltstone.


Marbel Formation (Pliocene)


The sequence is composed of biohermal limestone, marl, mudstone, sandstone and
local beds of local conglomerates. The environment by which this formation is deposi
ted
is under shallow marine to fluviatile.


Kilada Formation (Pleistocene)


Exposed predominantly in Barangay Kilada, M’lang, North Cotabato and
the
low hills of
Marbel area, the formation consists mainly of interbedded sequence of fine
-
grained
sandstone,
calcareous siltstone and cross
-
bedded conglomerates.


Omany Marl (Pleistocene)


The marl is predominantly greenish cream with abundant small foraminifera and contains
perfectly preserved oyster beds. It is best exposed in the area of Omanay, North
Cotabato
.


Quaternary Volcanic Complex


The volcanoes and other volcanic satellite centers of the Central

Mindanao Volcanic Arc
Complex we
re formed from the extrusion and outpouring of lavas and other volcanic
ejecta that were apparently produced as a result of p
artial melting of the Philippine Sea
Plate along the Philippine Trench. Volcanism in the region could have commenced
during Pliocene period and
endures to the present
.


Musuan and Kalatungan Volcanoes


Musuan Volcano located in Valencia, Bukidnon is an iso
lated tuff cone within a relatively
flat, agriculturally rich terrain. Contingent to this volcanic center, several inactive
volcanoes to its southeast could be related. These are: Tangulang, Malambo, Talemo
and Mt. Kalatungan with a maximum elevat
ion reach
ing to as high as 2,393

meters
above mean sea level. Volcanic activities in the past produced basaltic andesite on the
flanks while tuff dominates along gentler slopes.


The gen
eral geology of the Pulangi River Basin and the entire Mindanao River Basin
is
delineated in
F
igure 2
.
1
-
3
.




Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
6


F
igure 2
.
1
-
3

Geologic Formation


Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
7

2.1.4

River Conditions


The Pulangi River System, being the largest tributary of Mindanao River originates from
the headwater of Calabugao River in the northernmost limit of MRB. The upstrea
ms in
the western watersheds are generally occupied with pyroclastic materials from a series
of eruptions of Musuan and Kalatungan in Bukidnon and Ragang Volcanic Complex and
Lanao Volcanoes in the west. At the eastern volcanic center (Mt. Apo) of the basi
n, the
drainage systems of Arakan River and Kabacan River contribute large volume of
pyroclastics at the convergence of the rivers down to the Pulangi floodpla
ins before the
entry to the Liga
wasan Marsh.


In the development of the entire drainage system of

Pulangi River, four (4) important
geologic events and stages maybe derived: 1) Deposition of pyroclastic and volcanic
materials from cyclic eruptions of volcanoes around the headwaters area; 2) Mobilization
of pyroclastic materials to downstream sections;

3) Deposition of Lahar to floodplains
and river channels, and; 4) Deposition of delta deposits (sand and silt) and alluvium from
the confluences of the tributaries.


The stream section of Pulangi River where old lahar sediments are deposited may be
termed

as Volcanic Alluvial Plains whereas the convergence of several river systems
further downstream may be considered as Pulangi Flood Plains (from the continuous
deposition of river materials).


Where slower velocity of water occurs on bends and meandering p
oints of the main
stream, outward mobilization of huge amount of materials from the drainage system
resulted to the emergence of a lake, which is called
Ligawasan

Marsh. The large amount
of sediments carried by the slower movement of water coupled with the

convergence of
rivers has produced the prevalent delta deposits.


2.1.5

Sedimentation and Erosion


Erosion and sedimentation are the two (2) main processes that are responsible for the
landscape of Pulangi River System. Cyclic geomorphology of the river s
ystem would
reveal that erosion process involves the sculpting of old land to form new surfaces while
sedimentation shapes up new lands by building up silt and sand deposits. In some ways,
erosion compliments weathering of old rocks by which both destructi
ve and constructive
processes arise. In
Figure 2.1
-
4
, the longitudinal profile of Pulangi River from the
northwestern headwater down to the Illana Bay in Cotabato City is shown. The profile
indicates the stages of river development of Pulangi River as part

of the Mindanao River
Basin.


The deposited pyroclastic materials around the volcanic summits and slopes in western
watersheds were eroded and transported to the downstream channels of the Pulangi
River. In the northeastern drainage tributaries (Calabugao

River and Tigua River), the
erosive agent (water) carries sediments produced from the weathering and erosion of old
rock formations. On the other hand, the eastern drainage, which is triangulated with the
presence of Arakan River and Kabacan River, is dep
osited with pyroclastic materials
from the volcanic activity of Mt. Apo and its contiguous volcanic satellites. Erodible
pyroclastic materials in the form of voluminous fine particles associated with bouldery
fragments of volcanic lavas and flows occupy t
he main channels of these river systems.

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
8

The pyroclastic materials from the western drainage and eastern watersheds are carried
down to the downstream sections of Mulita River and Kulaman River and Arakan River
and Kabacan River confluences, respectively a
t around elevation 125 m amsl down to
elevation 30 meters in the general vicinity of the Carmen floodplain. Further downstream
and from the convergence of of drainage systems of Pulangi River were produced
deposits of alluvium materials and old lahar sedi
ments combined within the floodplains of
river system, which may be called as Pulangi Floodplain down to elevation 10 meters.
Sedimentation in this section involves weathering and erosion of pyroclastics, lahar
sediments from upstream and deposition of the

same through the processes of
erode
-
and
-
replace

or
destructive
-
constructive
cyclic events.


As lahar sediments, alluvium and weathered soil travelled downstream on slower velocity
along the main river system, the build
-
up (pile up) of fine
-
grained sand an
d silt sediments
led to the formation of the Ligawasan Marsh. This section of the river system then
becomes the catchment basket of the fine sediments from upstream. The elevation of
the Ligawasan Marsh, which has an average depth of 6 meters appears deepe
r than the
elevation of the river system (8 meters). This thereby entails continuous transport of
sediments to the marsh until the difference in the elevation is
de minimis
. Creeping push
down of materials in the Ligawasan Marsh has produced the continuous

flooding
downstream of the lake.




Figure 2.1
-
4

Longitudinal Profile of Pulangi River and Mindanao River



Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER







2
-
9

2.2

SOCIO
-
ECONOMIC CONDITIONS


2.
2
.1

Administration


The
P
ulangi
R
iver
B
asin

is located within the vicinity of
Regions of Caraga, Northern
Mindanao,

Davao Region, South Cotabato
-
Cotabato
-
Sultan Kudarat
-
Sarangani
-
General
Santos (
SOCCSKSARGEN
)

and the Autonomous Region in

Muslim Mindanao (ARMM).

Fifty
-
eight percent (58%) of the basin is located in Bukidnon

(Northern Mindanao)
, about
36% in North Cotabat
o

(SOCCSKSARGEN)
,
5
% in Lanao del Sur

(ARMM)

and the
remaining area

are shared by

Agusan del Sur

(Caraga)
, Davao del Sur, Davao del Norte
and Maguindandao

(ARMM)
.

The basin includes
42 Municipalities, 17

in Bukidnon, 14 in

Cotabato, 5 in Lanao del Sur,
2

i
n Agusan del Sur, 2 in Maguindanao,
1 in Davao del Sur and
1 in
Davao del Norte.
The covered

Municipalities are summarized in
Table 2.2
-
1
.

The municipalities of Loreto
and Veruela in Agusan del Sur, and Baungon and Sumilao in Bukidnon are
also covered
in t
he basin. However, it is
not included

in the
analysis due to
its
very small

population

count

and
area.

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
10


Table 2.2
-
1

List of Provinces and Municipalities in Pulangi River Basin





See Figure 2.2
-
1







Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
11



Figure 2.2
-
1

Municipalities within Pula
ngi River Basin

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
12

2.
2
.
2

Population

(1)

Present Population

The population of each of the municipalities within the basin derived from the
2007 population data of the National Statistics Office (NSO) is
presented

in
Table
2.2
-
2
.
The ratio of population within
the basin
was

computed
as

an

estimate
of
population distribution in the area.




Table 2.2
-
2

Population within Pulangi River Basin



Source:
N
ational Statistics Office

Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
13

(2)

Population Density

Table 2.2
-
3

shows the population density within the basin.
Am
ong the
municipalities, Davao City, w
ith a population of 6,557
,

land area of 10.70 km
2
,
and
an estimated population density

of
613
persons/
km
2
,

is

the most densely
populated.

On the othe
r hand, the municipality of La P
az in Agusan de
l Sur, with a
populatio
n of 141,

a land area of 5.76 km
2

and an estimated population density of
24 persons/km
2
, is the least densely popul
ated
.


Table 2.2
-
3

Population Density within
Pulangi

River Basin





Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
14

(3
)

Number of Households and Household Size

Based on the data presente
d in
Table 2.2
-
4
,

the number of households
in

the

provinces
within the basin

increased from 2000 to 2007.

Among

the provinces,
Lanao del Sur the highest increase pegged at
58%
.


As
likewise

shown in the same table,

the average household

size of the provinc
es
decreased

from 2000 to 2007.

The computed average household size of the
provinces

marked

5.14
,

a figure

lower than the
national
average household size
,

which is 4.67
.



Table 2.2
-
4

Number of Households and Average Household Size


Source: N
ational Stati
stics Office


The number of households
of the municipalities
within the basi
n is determined
using the average household size c
omputed from the previous table
,

and is
shown in
Table 2.2
-
5
.


Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
15


Table 2.2
-
5

Number of Households within the Basin




(4
)

Annual

Growth Rate of Population


As shown in
Table 2.2
-
6
,

Maguindanao province grew at an annual rate of 6.99%,
which is three times the national
average

of 2.04%.
On the other hand, Lanao del
Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
16

Sur,
recorded

an annual

growth

rate of 4.98%,
twice the national ann
ual rate
value.

No
rth Cotabato,
having an annua
l growth rate of 2.19%, was

closest to the
national average. The rest of the provinces

posted a lower value of population
growth rates.


Table 2.2
-
6

Annual population growth rate of

the

Provinces within the B
a
sin




(5
)

Projected Population by 2035

Using geometric method, the projected population by 2035
wa
s computed and
the results are
as
shown in
Table 2.2
-
7
.

In the computa
tion, the 2007 population
data wa
s used as base
line

data
,

and growth rate

from 2000 t
o 2007 for each
municipality
was assumed constant

until 2035.


























Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
17

Table 2.2
-
7

Present and Projected Population within the Basin by 2035





2.2.3

Land Use Condition

The present
land cover condition

of the PRB is shown in
Figure 2.2
-
2

as
obtained from
the 2007 National Mapping and Resource Information Authority (NAMRIA)
Geographic
Information System (
GIS
)
.








Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
18



Figure 2.
2
-
2

Present Land Cover Condition


Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
19

Based on the
above

figure,
4,141.71 km
2

or 43.64
% percent of the
area

within th
e basin

is used in cultivating annual crops

and a
bout 19.26% is
allotted for

shrubs.

The summary
of the
land cover classification

and its respective area

is presented in
Table 2.2
-
8
.



Table 2.2
-
8

Land Cover C
lassification
s within the B
asin





2.2.4

Econ
omic Profile


Ninety fo
ur percent (94%) of the PRB is administratively under

the provinces of Bukidnon
and Cotabato.
According to the Philippine National Statistical Coordination Board
(NSCB),

the
Gross Regional Dom
estic Product (GRDP)

of Northern Mindanao

decelerated

from 6.9% in 2010 to
2.5% in 2011 while the GRDP growth rate of

SOCCSKSARGEN

R
egion

increases from
2.0% to 4.0% in the same year.


The major sectoral contribution of Northern Mindanao in
2009 and
2011
is shown in
Figures 2.2
-
3
a
and

2.2
-
3
b

whil
e
Figure 2.2
-
4
a

and
2.2
-
4
b

show the same
for
SOCCSKSARGEN
.

The negative GRDP of Northern Mindanao
wa
s mainly
attributed

to
the de
celeration of the AFF (Agriculture, Forestry and Fishery) and industry sector
s
.
On
the other hand,
the service sector in
SOCCSK
SARGEN

primarily served as the biggest
contributor to the growth of GRDP in the R
egion.







Department of Environment and Natural Resources (DENR)

River Basin Control Office (RBCO)

Mindanao Development Authority (MINDA) and t
he

Presidential Task Force on the Mindanao River Basin and
Rehabilitation Development (PTF
-
MRBRD)

Mindanao River Basin Integrated Management

and Development Master Plan


PRE
-

FEASIBILITY STUDY OF AN INTEGRATED

FLOOD CONTROL, RIVER BANK PROTECTION AND
RE
HABILITATION PROJECT FOR PULANGI RIVER






2
-
20


Source: National Statistical Coordination Board


Figure 2.2
-
3

Northern Mindanao Major Sectoral C
ontribution;

(a)

year 2009 and (b) 2011





Source: National Statis
tical Coordination Board

Figure 2.2
-
4

SOCCSKSARGEN

Major Sectoral Contribution;

(a) year 2009 and (b) 2011