Geographic
Location
The
towns geologic feature exhibits three major rock components
namely: alluvium (QAL), proclastic (Qvp and volcanic
(Qv).
Alluvium
(Qal) are unconsolidated mixture of sand, gravel and
considerable sit and clay found mostly in coastal and
flood plain areas. This is the smallest single type
of rock found in the municipality. It covers about 9.3%
of the total land area covering the entire western section
of the town less than one kilometer from the nearest
point of Laguna de Bay. It occupies approximately 24.0%
of Barangay San Juan and 28.5% of Barangay Longos. Pyroclastic
rocks (Qvp) are most agglomerates, volcanic breccia
and some tuff and volcanic cinders. They are generally
found in the foothills of volcanic cones. In Kalayaan,
it is the second largest single type of rock formation
occupying most of the northern half of the town along
the boundaries with Paete and Mauban, Quezon in the
east.
Volcanic
rocks (Qv) are chiefly andesite and basalt flows with
some intercalated pyroclastic rocks generally found
around volcanic vents and also occur as fissure eruptions.
IT is the largest single type of rock formation found
in the town covering approximately 47.2% of the total
municipal area. It is found mostly in the southern half
of the town covering approximately 76.0% of San Juan,
16.1% of Longos and 40.4% of San Antonio. (Table 4 Geologic
Feature).
LAND
AREA
The exact
land area of the municipality is uncertain up to the
present because of the varying figures given by the
agencies authoritative on the matter. The National Census
and Statistics Office (NCSO) approximate it to be around
4,660 hectares composed of only three but rather large
barangays. This figure will be used for planning purposes.
Barangay San Juan which is presently considered as the
Poblacion of the town is approximately 1,227 hectares
of 26.3% of the total municipal land area. (Table 1:
Land Area by Barangay).
TABLE
1
LAND AREA BY BARANGAY
1984
BARANGAY
|
APPROXIMATE
LAND AREA
|
Hectares
|
Percentage
Distribution
|
San
Juan Longos San Antonio |
1,227
492
2,941
|
26.3%
10.6%
63.1%
|
Total |
4,660
|
100%
|
TOPOGRAPHY
Kalayaan
is rectangular in shape with hilly terrain on most of
its eastern side while relatively flat on its western
side. Its highest elevations are from 400 to 418 meters.
These are found in Sitio Santo Angel, Malaking Pulo
and Cabuhayan in Barangay San Juan and Sitio Lamao in
Barangay San Antonio. Approximately three-fourths of
the total land area are with terrain 300 meters and
above. Its lowest points are from five to 20 meters
along the western sections of Barangays San Juan and
Longos towards Laguna de Bay. Its surface water comes
in the form of lakes and numerous rivers, streams and
creeks (Table 2: Inventory of Rivers and Creeks 1984).
San Juan and Longos Rivers wind up into Laguna de Bay
towards the western border of the town. The terrain
of the municipality has given rise to famous resorts
and picnic grooves known to both local and foreign tourists.
Aside from these, however, the town has no other prominent
topographic feature. The bigger 91.4% of the town has
fair water bearing capacity. This area covers the elevated
portion of the town representing the entire area of
Barangay San Antonio and 22.7% and 8.3% of Barangay
San Juan and Longos, respectively.
TABLE
2
RIVERS AND CREEKS
1984
RIVER
- CREEK
|
LOCATION
|
San
Juan River
Longos River
Gumihan River
Nalba River
Tisanian River
Bay River
Ginabihan River
Naiba River
Pulot River
Caliraya River
Lumot Creek
Tabagin Creek
Palanas Creek
Pinagtiklihan Creek
|
San
Juan
Longos
Lamao, San Antonio
Kalayaan, San Antonio
Kalayaan, San Antonio
Kalayaan, San Antonio
Kalayaan, San Antonio
Kalayaan, San Antonio
Magalolon, San Antonio
Magalolon, San Antonio
Lunao, San Antonio
Magalolon, San Antonio
Magalolon, San Antonio
Magalolon, San Antonio |
Source:
Drainage and Sewerage Map
CLIMATE
Kalayaan,
like the rest of the municipality of Laguna, experiences
Type I of the Philippine climate that has two pronounced
seasons, dry and wet. Dry season occurs during the months
of November through April while the wet season occurs
during the rest of the year. (Map I: Vicinity and Weather
Map). This prevailing climatic condition affected by
proximity to hills and lakes is most favorable to agriculture
and vegetation.
RAINFALL
Heavy
rains usually start in May and continue through September
with slight variations in duration, frequently and intensity.
In 1982, it was most intense during the months of July,
August and September when average monthly readings were
recorded at 320.5, 191.6 and 454.4 millimeters, respectively.
Understandably, it was lightest at 15 millimeters during
dry season particularly in the months of February and
March. . In terms of frequency, July, September and
November were rainiest during the same period with a
total of 23 rainy days each for September and November.
(Table 3.3: Climatologican Data, 1982).
TEMPTERATURE
The average
temperature in 1982 was 27.3 C. Temperature during the
same year was highest in May and June at 29.3 C, and
lowest in January at 24.5 C.
RELATIVELY
HUMIDITY
Relative
humidity is highest in September with a reading of 80% and lowest in
March with a reading of 73%. This makes the month of
September most humid and
March driest (Table).
TABLE
3
CLIMATOLOGICAL
DATA
1982
MONTH
|
RAINFALL
|
TEMP(C)
|
RELATIVE
HUMIDITY
|
WIND
|
No.
of Tropical Cyclone
|
|
MM
|
Days
|
|
|
Prevailing
Direction
|
Ave.
Speed (KPH)
|
|
January
|
14.0
|
9
|
24.5
|
78
|
East
|
4.1
|
0
|
February
|
12.2
|
8
|
25.5
|
78
|
North
East
|
5.5
|
0
|
March
|
12.6
|
6
|
27.2
|
73
|
East
|
4.5
|
2
|
April
|
43.9
|
7
|
28.1
|
75
|
North
East
|
3.3
|
0
|
May
|
54.0
|
9
|
29.3
|
74
|
North
East
|
3.1
|
1
|
June
|
81.2
|
15
|
29.3
|
74
|
East
|
3.3
|
0
|
July
|
320.5
|
23
|
27.6
|
79
|
West
|
3.4
|
5
|
August
|
191.6
|
16
|
27.5
|
78
|
North
East
|
2.3
|
4
|
September
|
454.4
|
21
|
27.3
|
80
|
East
|
2.3
|
4
|
October
|
54.8
|
16
|
27.2
|
76
|
East
|
2.1
|
3
|
November
|
74.4
|
21
|
27.0
|
79
|
East
|
2.2
|
0
|
December
|
121.17
|
10
|
26.6
|
77
|
East
|
2.4
|
2
|
ANNUAL
|
1,435.3
|
161
|
27.3
|
77
|
East
|
3.2
|
21
|
Source:UPLB,CEAT
Geographic Location
The
towns geologic feature exhibits three major rock components
namely: alluvium (QAL), proclastic (Qvp and volcanic
(Qv).
Alluvium
(Qal) are unconsolidated mixture of sand, gravel and
considerable sit and clay found mostly in coastal and
flood plain areas. This is the smallest single type
of rock found in the municipality. It covers about 9.3%
of the total land area covering the entire western section
of the town less than one kilometer from the nearest
point of Laguna de Bay. It occupies approximately 24.0%
of Barangay San Juan and 28.5% of Barangay Longos. Pyroclastic
rocks (Qvp) are most agglomerates, volcanic breccia
and some tuff and volcanic cinders. They are generally
found in the foothills of volcanic cones. In Kalayaan,
it is the second largest single type of rock formation
occupying most of the northern half of the town along
the boundaries with Paete and Mauban, Quezon in the
east.
Volcanic
rocks (Qv) are chiefly andesite and basalt flows with
some intercalated pyroclastic rocks generally found
around volcanic vents and also occur as fissure eruptions.
IT is the largest single type of rock formation found
in the town covering approximately 47.2% of the total
municipal area. It is found mostly in the southern half
of the town covering approximately 76.0% of San Juan,
16.1% of Longos and 40.4% of San Antonio. (Table 4 Geologic
Feature).
TABLE
4
GEOLOGIC FEATURE
BRGY.
|
TOTAL
LAND AREA (Hectares)
|
ROCK
COMPONENT
|
Alluvium
(Qal)
|
Pyroclastic
(Qvp)
|
Volcanic
(Qv)
|
Hectares
|
Percent*
|
Hectares
|
Percent*
|
Hectares
|
Percent*
|
San
Juan
Longos
San Antonio |
1,227
492
2,941
|
294
140
-
|
24.0
28.5
-
|
-
273
1,753
|
-
55.4
59.6
|
933
79
1,188
|
76.0
16.1
40.4
|
TOTAL
|
4,600
|
434
|
9.3
|
2,026
|
43.5
|
2,200
|
47.2
|
Source:
LLDA
*Percent of total barangay and municipal area
GROUND
WATER RESOURCES
The geologic
feature discussed earlier indicates ground water resources,
which range from good to fair in classification. (Table
5: Ground Water Resources).
TABLE
5
GROUND WATER RESOURCES
BRGY.
|
TOTAL
LAND AREA
|
GROUND
WATER RESOURCES
|
GOOD
|
FAIR
|
Hectares
|
Percent
|
Hectares
|
Percent
|
San
Juan
Longos
San Antonio |
1,227
492
2,941
|
259.5
140.0
-
|
65.0
35.0
-
|
967.5
352.0
2,941.0
|
22.7
8.3
69.0
|
TOTAL
|
4,660
|
399.5
|
8.6
|
4,260.5
|
91.4
|
Source: LLDA
Only about
8.6% of the municipality has good water bearing characteristics
with high potential for ground water development.
This area covers the entire western section of the
town extending less than one kilometer from the nearest
shore of Laguna de Bay. It occupies approximately
65.0% of Barangay San Juan and 35.0% of Barangay Longos.
SLOPE
The town,
though generally rolling in slope, is characterized
by slope Types A to F which range from level to mountainous
in characteristics. (Table 6: Slope Classification)
TABLE
6
SLOPE CLASSIFICATION
TYPE
|
RANGE
|
CHARACTERISTICS
|
AREA
|
Hectares
|
Percent
|
A
B
C
D
E
F
|
0.0
- 2.5%
2.6 - 5.0%
5.1 - 10.7%
10.1 - 18.0%
18.1 - 25.0%
25.1 and above |
Level
to nearly level
Very gently sloping or undulating
Gently sloping or undulating
Moderately sloping or rolling
Strongly sloping or rolling
Strongly hilly to mountainous |
1,198
223
318
2,206
299
416
|
25.7
4.8
6.8
47.3
6.5
8.9
|
|
|
|
4,660
|
100.0
|
Source:
LLDA
SOIL
Slope Type
D that ranges from 10.1 to 18.0% with moderately sloping
or rolling characteristics is the largest single slope
area in the municipality. It accounts for about 2,206
hectares representing 47.3% or almost one-half of the
total municipal area. It is found in all barangays occupying
mostly the southern half of the town extending up to
its mid-northwestern section as well as major parts
of its northeastern corner. (See Slope Map).
Slope Type
A which ranges from 0.0% to 2.5% with level nearly characteristics
is the second largest slope area in the town accounting
for approximately 25.7% of the total municipal and area.
It is concentrated in two major points of the town:
one covering its entire western end less than one kilometer
from the nearest point of Laguna de Bay in Barangay
San Juan and Longos; the other, right in the middle
of the town extending northward. These areas are very
favorable to crop cultivation and urban utilization
slopewise.
Slope Type
E and F which range from strongly sloping to mountainous
account for another 715 hectares representing about
15.4% of the total north to south intersecting the mis-western
portion of the town in Barangays Longos and San Juan
and in three more points in Barangay San Antonio specifically
in this barangay's north easternmost corner, mid-eastern
section along the boundary with Quezon Province and
right in the center also running eastward.
Being strongly
rolling and mountainous, they are highly susceptible
to soil erosion and are difficult to develop making
it unfavorable for agricultural production and urban
development. With slope range above 18%, they may permanently
from part of the town's forest reserves if part of the
public domain.
Slope Type
C that ranges from 5.1 to 10.0% with gently sloping
or undulating characteristics accounts for another 318
hectares approximately 6.8% of the total municipal area.
It is found in the northeastern part of Longos along
the boundary with Paete and in a patch in the mid-northern
section of San Antonio. With its gently sloping or undulating
terrain, it is classified as fairly tolerant to development.
Slope Type B, which ranges from 2.6 to 5.0% with very
gently sloping or undulating characteristics accounts
for the smallest single slope-area with 223 hectares
share approximately 4.8% of the total land area. It
is found in two patches in the middle of Barangay San
Antonio.
SOIL
Basic
Soil Type
There are
five basic soil types in the municipality. These are
Tidal fresh water marsh series Mf4, Bay clay series
ByBA, Paete clay loam series PeHA, PeHC2, PeHD3, PeHE4
and PeHF4, Luisiana clay series LuBA, LuBD3, and LuBF4;
and undifferentiated mountain soil series MsUB, MsUC2,
MsUD3, MsUE4 and MSUF4.(Table 7: Basic Soil Classification).
TABLE
7
BASIC SOIL CLASSIFICATION
BASIC SOIL
TYPES
|
AREA
|
HECTARES
|
PERCENT
DISTRIBUTION
|
Tidal
Fresh Water Marsh
Bay Clay
Paete Clay Loam
Luisiana Clay
Undifferentiated Mountain Soil |
171
212
1,278
1,461
4,660
|
3.7
4.5
27.5
31.4
100.0
|
Source: LLDA Soil Study
Soil series
are groups of soils derived from the same parent material
that are similar in profile characteristics, relief
and drainage except for the surface texture.
Tidal fresh
water marsh series Mf4 is the smallest single type
in the municipality accounting for only 171 hectares
or 3.7% of the total municipal area. It is found in
the watermost section of the town along the shore
of Laguna de Bay specifically in Barangays San Juan
and Longos.
Bay clay
series ByBA is similar not extensive in the municipality
covering only about 212 hectares or 4.5% of the total
municipal area. This soil series is normally utilized
for paddy rice production. They are generally poorly
drained due to their low based position and poor permeability
due to clayey solum textures. They are highly suitable
for the cultivation of rice, tree crops and diversified
crops as well as for urban uses. Their surface texture
is clay loam with clayey textures of minor extent
included. They are found in the western side of the
municipality specifically in Barangays San Juan and
Longos next to the tidal fresh mater marsh.
Paete series'
soil formation is derived from the physical and chemical
weathering of igneous rocks of basalt and andesites.
It is quite extensive in the municipality covering
about 1,278 hectares or 27.4% of the total municipal
area. Its profile characteristics are moderately deep-to-deep
reddish brown granular clay loam to clay. Its external
drainage is rated good to excessive while fair to
poor internally. This soil, mostly found in the western
half of the town, covers large areas of Barangays
San Juan and Longos. This soil is not suitable for
paddy rice, for diversified crops and marginally to
moderately suitable for tree crops.
Luisiana
soil is formed from weathered products of igneous
rocks of basalt and andesites. Its relief varies from
undulating to rolling and mountainous causing variation
in th degree and extent of soil erosion hazards. It
is the second largest single soil type in the town
covering 1,461 hectares or 31.4% of the total municipal
area. This soil type exhibits a deep well-drained
relief with friable granular clay loam to clay profile
textures. It is found in the southern half of the
town extending at a decreasing proportion mid-northward
covering the Barangays of San Juan and San Antonio.
This soil is generally suitable for paddy rice, tree
crops, diversified crops and grazing depending on
slope characteristics. In Kalayaan, they are mostly
in areas with slope 10.1% to 18.0% which renders them
only marginally suitable for tree and diversified
crops and not suitable for paddy rice cultivation.
Undifferentiated
mountain soil covers the largest single soil type
in the municipality accounting for an approximate
total of 1,538 hectares, about 33.0% of the entire
municipal area. It is found in the eastern section
of the town affecting a large area of Barangay San
Antonio.
For a more
comprehensive discussion of the suitability, capability,
drainage, erosion and flooding implications of these
soil types, refer to the preceding sections of this
chapter.
Land
Capability
The physical
characteristics of the municipality particular its
soils and slope, exhibit a generally fairly good land
in terms of capability.
Very good
land (a) is the second biggest slice of land comprising
about 876 hectares representing 18.8% of the total
municipal area. It is found in the level to nearly
level central portions of the municipality extending
northward covering the northeastern section of Longos
and a big proportion of San Antonio. These lands are
highly suitable for urban use and can be cultivated
safely requiring only simple but good farm management
practices.
Good lands
(Be and Bw) total 414 hectares or 8.9% of the total
municipal area and are found at two points contiguous
to the very good lands in San Antonio (be) and in
the western section of the town (Bw) in Barangays
Longos and San Juan along the shore of Laguna de Bay
at one point and, thereafter, at an average of less
than one kilometer from the shore until the national
highway. Good lands classified Bw are nearly level
occurring in depression. It can be cultivated safely
but requires protection from occasional overflow and
easily applied conservation techniques and soil management
practices. Good land classified Be are nearly level
of undulating and slightly to moderately eroded. It
could be cultivated safely but requires erosion control
measures and easily applied conservation. Both lands
can be urbanized.
Moderately
good lands (Ce and Cw) account for 10.1% of the total
municipal area. Ce are moderately good land which
are nearly level in terrain found mostly in the foothills
of very steep and strongly sloping lands in two. These
lands could be cultivated safely but requires protection
from frequent overflows, carefully designed drainage
system and careful management practices. Only San
Antonio and Longos exhibit this land capability.
Cw, on
the other hand, are those lands found along the shores
of Laguna de Bay which could be taken as swamps and
marshlands because they are constantly under water
being part of the lake bed. They are also rated moderately
good in land capability with slope rated as nearly
level. They are not suitable for urban utilization
because they are classified as flood prone areas.
Similar to the Ce, they can be cultivated productively
but require protection from frequent overflow, carefully
designed drainage system and careful management practices.
These lands alone comprise around 158 hectares or
3.4% of the municipal area and are found only in Barangays
San Juan and Longos.
Fairly
good lands (De) account for the bigger 2,200 hectares
or almost one-half (47.2%) of the total municipal
area. These are found in all barangays occupying mostly
the southern half of the town extending up to its
mid-northwestern section as well as major parts of
its northeastern corner. Strongly sloping or rolling
terrains, which are severely susceptible for urban
development, characterizes fairly good lands. It can
be cultivated occasionally of handled with proper
care complemented with careful management as well
as complex conservation practices. It is best for
pasture and forest purposes.
Steep (m)
and very steep (N) lands account for another 701 hectares
or 15.0% of the total municipal area. These are found
running from north to south intersecting the western
portion of Barangays Longos and San Juan and in four
more points in Barangay San Antonio specifically in
the northeastern corner, mid-eastern section along
the boundary with Quezon Province, right the middle
also running eastward and in the mid-northern section
along the boundary with Paete running eastward up
to the middle of the Barangay. Both lands have very
severe erosion potential classified as strongly rolling
to mountainous. Like the fairly good lands, they are
generally classified as poor to not suitable for urban
use nor cultivation because of the inhibitive cost
associated with their development. Steep land (M)
are also best suited for pasture or forest purposes
with careful management practices. Very steep lands
(N) are similarly rough for cultivation but can be
used for grazing with careful management techniques
and restrictions. If is, however, best suited for
forest purposes with careful management practices.
(Table 8: Land Capability).
TABLE
8
LAND CAPABILITY
BASIC
SOIL TYPES
|
AREA
|
HECTARES
|
PERCENT
DISTRIBUTION
|
A
- Very good land
Be - Good Land
Bw - Good Land
Ce - Moderately Good land
Cw - Moderately Good land
De - Fairly Good land
M - Steep
N - Very steep land
|
876
215
199
311
158
2,200
292
409
|
18.8
4.6
4.3
6.7
3.4
47.2
6.2
8.8
|
TOTAL
|
4660
|
100.00
|
Source: LLDA
Soil
Suitability
As reflected
by its land capabilities, the soil characteristics
of the town is generally not suitable for the cultivation
of rice, marginally suitable for tree crops and diversified
crops and moderately suitable for urban use. (See
Soil Suitability Map).
Soil
Suitability for Rice Crop
The area
generally not suitable for rice cultivation covers
2,880 hectares of 61.8% of the entire municipal area.
They are found in all three barangays occupying almost
the entire southern half of the town extending up
to its mid-northwestern section as well as upper northeaster
corner. These areas are characterized principally
by Paete clay loam, Luisiana clay and undifferentiated
mountain soil and slope types D, E and F which range
from 10.1% to 25.1% and above, moderately sloping
or rolling to strongly hilly to mountainous. Rice
crop cultivation in this area is not suitable due
to the presence of very serious limitations and restrictions
such as high degree of erosion potential due to steep
slope, which renders the soil not economical to use
under any management technique.
Areas highly
suitable for rice cultivation cover only 1.075 hectares
or 23.0% of the total municipal area. They cover portions
of all three barangays but are more extensive in Barangay
San Antonio. Specifically, they are found in the western
side of the town along the shore of Laguna de Bay
at one point and thereafter, less than an average
of one kilometer from the same. They are also found
right in the middle of the town extending mid-northward
towards Paete mostly in the periphery of Barangay
San Antonio. These areas are characterized by Bay
clay soil and the three other soil types earlier mentioned
and slope Type A or 0.0 to 2.5%, level to nearly level.
Rice crop cultivation in this area is relatively profitable
even with simple farming techniques with good management
practices. Slight soil limitations, if any, are easy
to overcome.
The remaining
15.2% of the total municipal land area range moderately
to marginally suitable for rice production, the marginally
suitable portion being the larger 10.1% composed mainly
of Paete clay loam and undifferentiated mountain soil
with slope ranging from 0.0 to 10.0%. They are found
along the northeastern border with Paete, in the mid-northern
section of San Antonio and in the immediate shores
of Laguna de Bay in the west. Moderately suitable
for rice cultivation account for the least area, only
5.1% of total municipal land composed mainly of undifferentiated
mountain soil with slope ranging from 2.6 to 5.0%.
They are found in two patches north of the highly
suitable lands in San Antonio. Rice cultivation in
these areas is hampered by the presence of minor to
serious soil limitations or restrictions, which could
still be overcome with easily applied farming practices
and special management techniques. (Table 9: Soil
Suitability and Map in Soil Suitability for Rice Crop).
TABLE
9
SOIL SUITABILITIES
SOIL
SUITABILITY
|
RICE
CROP
|
TREE
CROP
|
DIVERSIFIED
CROP
|
URBAN
USE
|
Has.
|
%
|
Has.
|
%
|
Has.
|
%
|
Has.
|
%
|
High
Moderate
Marginal
Not Suitable
|
1,075
236
469
2,880
|
23.0
5.1
10.1
61.8
|
1,269
332
2,880
179
|
27.2
7.2
61.8
3.8
|
1,075
526
2,221
838
|
23.0
11.3
47.7
18.0
|
1,583
2,197
313
567
|
34
47
6
12
|
TOTAL
|
4,660
|
100.0
|
4,660
|
100.0
|
4,660
|
100.0
|
4,660
|
100.0
|
Soil
Suitability for Tree Crops
Only about
27.2% of the total land area is highly suitable for
tree crop cultivation. These are the same areas rated
highly suitable for rice production, which expanded
to include those that are only moderately suitable
for the same. These soils are suitable for tree crops
under simple but good management practices. Slight
soil limitations, if any, are easily overcome.
Rated moderately
or fairly suitable for the same purposes are those
areas rated marginally suitable for rice crops in
two points along the boundary with Paete. These lands
total to approximately 332 hectares or 7.2% of the
total municipal area and are characterized by the
presence of minor or moderate soil limitations or
restrictions that can be overcome with easily applied
farming practices.
Poor or
marginally suitable for tree crops cultivation accounts
for the largest 61.8%. These are the same areas rated
not suitable for rice cultivation due to the presence
of serious soil limitations, which could be overcome
with intensive and complex farming practices as well
as special management techniques. The other 3.8% is
rated not suitable for the same purpose. These are
the areas found in the immediate periphery of the
lake. The presence of very serious soil limitations
or restrictions in these areas render the soil not
suitable or economical to use under management techniques.
(Table 9 and Soil Suitability For Tree Crops Map).
Soil
Suitability for Diversified Crops
Soils highly
suitable for diversified crop cultivation are similarly
not extensive, only 23.0% of the entire municipal
area. They cover the same areas in the western and
middle part of the town which are also highly suitable
for rice and tree crop cultivation extending to all
lands with slopes classified level to nearly level
(0.0 - 2.5%). Portions of all three barangays reflect
this soil suitability but is most extensive in San
Antonio as earlier mentioned. Rated fair or moderately
suitable for diversified crop cultivation are those
areas with very gently sloping or undulating terrain
(2.6 - 10.0%) found mostly in Barangay San Antonio.
Marginally or poor suitable areas account for the
largest 47.7% of the total municipal area and are
found extensive in all three barangays especially
San Juan and San Antonio. Classified poor or not suitable
are the same areas classified strongly sloping to
mountainous in slope and those in the immediate vicinity
of Laguna de Bay. The same limitations and constraints
mentioned earlier were used in classifying these lands
as such. (Table 9 and Soil Suitability For Diversified
Crops Map).Soil Suitability For Urban Use Typical
to areas with mostly moderately sloping or rolling
terrain, the municipality is rated generally, only
moderately suitable for urban use with almost one-half
of its total land area falling under this classification
and the rest either highly, marginally or not suitable.
Rated highly
suitable for urban use are some 1,538 hectares of
land or 34.0% of the total municipal area. Basically,
these are the same areas rated highly suitable for
rice, tree crops and diversified crop cultivation
in the previous soil suitability discussion. (Please
refer) all barangays exhibit areas of this classification
but are more extensive in San Antonio.
Soils moderately
suitable for urban use are similarly found in all
barangays but rather more extensively with its 2,197
hectares or 47.1% share of total land area, the biggest
share as earlier mentioned. These are the areas with
moderately sloping or rolling terrain, a soil profile
characteristics rated as such primarily because of
severe erosion potential. (Refer to the Section on
Erosion Potential).
Lands
rated poorly and not suitable for this purpose are
generally strongly hilly to mountainous with urban
development constraints ranging from very severe erosion
potential and other unfavorable soil properties which
are most difficult and costly to overcome. All three
barangays have soil of these classification at varying
extent.
Likewise
rated not suitable for this use are the areas in the
immediate periphery of Laguna de Bay. Although plain
and level in slope, these areas are rated as such
because of flooding hazards brought about by occasional
lake overflow. (Table 9 and Soil Suitability For Urban
Use Map)
EROSION
POTENTIAL
Erosion
is the process by which soil particles are removed
and transported by run-off water. The degree and length
of the slope of an area well as the absence of adverse
relief and pressure on the soil are major contributory
factors to its erosion potential.
The soil
and slope of Kalayaan (Section 3.6 and 3.7) exhibit
an area that range from no apparent erosion to severe
erosion potential. (Table 10: Erosion Potential)
TABLE 10
EROSION POTENTIAL
BASIC
SOIL TYPES
|
HECTARES
|
PERCENT
DISTRIBUTION
|
None
Slight
Severe
Very Severe
|
1,406
332
2,221
701
|
30.2
7.1
47.7
15.0
|
TOTAL
|
4,600
|
100.00
|
The greater
portion of the town (47.7%) shows severe erosion potential.
These are the moderately sloping or rolling parts,
which occupy the greater portion of the municipality
with concentration on its lower southern half. Slope
Type D or 10.1 to 18.0% and a mixture of Paete clay
loam, Luisiana clay and undifferentiated mountain
soil characterize these parts of the town (see Table
6 and Soil Erosion Map).
Areas with
no apparent erosion occupied another, 1,406 hectares
accounting for approximately 30.2% of the total municipal
land area. These are the same areas with slope 0.0
to 2.5%, which are level to nearly level in description.
They are found in he westernmost section of the town
along Laguna de Bay and in the middle section of the
town running northward on one end and eastward on
the other. It is seen to be most extensive in San
Antonio.
The erosion
potential of the rest of the municipality vary from
slight to very severe. Areas with very severe erosion
potential accounts for approximately 15.0% of total
area. These are those areas with slope types E to
F or 18.1% and above which are strongly sloping and
mountainous found running from north to south in the
mid-western section of the municipality in four different
points in the northeastern corner in Barangay San
Antonio. Areas with slight erosion potential, on the
other hand, account for the least 7.1% and are found
in two points in the north along the boundary with
Paete. These are the areas with slope 2.6% to 5.0%
which are classified as very gently sloping or undulating.
|