20
Figure 4.3. Description for soil type in study area Vitrandepts-Eutropepts association is a porous soil, which developed from volcanic
ash Hart et al, 2004. Depending on the above parent material and weathering force, those soil type characterized by low soil organic matter, even though they is developed by
deposits material from upper area and leaching process not as intensive as upper area. So have low K value, about 0.05
– 0.10, because erodibility can reduced if soil structure in stable caused by organic matter bounding.
Dystropepts-Tropudults association is a mature soil type, which weather process intensively and high in clay.
IV.3. L
AND COVER CHANGES
Based on Landsat data there are 10 classes of land cover can be identified, which are forest, bushscrub, mix garden, built up, paddy field, upland, tea plantation, bare land,
grass and water. In total 9629.23 ha of study area were evaluated for land cover changes. Table 4.1
presents about land cover changes from 1991 until 2006. In detail, land cover change processes can seen in Appendix.
Dystrandepts-Hidrandepts Association
Vitrandepts-Eutropepts Association
Dystropepts-Tropudults Association
Telaga Warna
21
Table 4.1. a. Land cover changes from 1991 until 2006
1991 1994
1997 2001
2004 2006
hectare
Forest 3315.51
3162.60 2978.64
2726.73 2474.19
2000.340 Bush
1043.46 1027.62
1286.10 1171.62
1677.87 1393.660
Mix garden 574.74
898.47 422.64
804.78 409.06
824.490 Built up
133.11 255.06
352.35 457.65
743.76 1058.580
Paddy field 30.24
38.88 29.70
137.61 126.36
60.750 Upland
1172.25 904.32
1373.22 1215.99
977.13 920.250
Tea plantation 562.41
968.31 749.79
663.75 923.61
748.290 Bare land
763.83 318.42
301.68 124.29
224.56 582.22
Grass 8.46
29.88 111.24
310.77 53.01
21.24 Water
0.54 0.90
11.25 2.43
1.53 1.26
Cloud 4.14
4.14 4.14
4.14 4.14
4.14 Shadow
8.01 8.01
8.01 8.01
8.01 8.01
b. Trend cover changes from 1991 until 2006
1990-1994 1994-1997
1997-2001 1997-2004
2004-2006 Total Change
percent
Forest -1.59
-1.91 -2.62
-2.62 -4.92
-13.69 Bush
-0.16 2.69
-1.19 5.26
-2.95 3.64
Mixgarden 3.37
-4.95 3.97
-4.11 4.32
2.60 Builtup
1.27 1.01
1.09 2.97
3.27 9.63
Paddy field 0.09
-0.10 1.12
-0.12 -0.68
0.32 Upland
-2.79 4.88
-1.63 -2.48
-0.59 -2.62
Tea plantation 4.22
-2.27 -0.89
2.70 -1.82
1.93 Bareland
-4.64 -0.17
-1.84 1.04
3.72 -1.89
Grass 0.22
0.85 2.07
-2.68 -0.33
0.13 Water
0.00 0.11
-0.09 -0.01
0.00 0.01
Cloud 0.00
0.00 0.00
0.00 0.00
0.00 Shadow
0.00 0.00
0.00 0.00
0.00 0.00
The rates of land conversion between 1991, 1994, 1997, 2001, 2004 and 2006 are given in Figure 4.4. The negative bars represent land types that decreased in extent,
whereas positive bars indicate land type that expanded.
22
F o
re st
Bu sh
M ix
g a
rd e
n Bu
il tu
p Pa
d d
y fi
e ld
U p
la n
d T
e a
p la
n ta
ti o
n Ba
re la
n d
G ra
ss W
a te
r C
lo u
d Sh
a d
o w
-6.00 -5.00
-4.00 -3.00
-2.00 -1.00
0.00 1.00
2.00 3.00
4.00 5.00
1990-1994 C
h a
n g
e
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
F o
re s
t B
u s
h M
ix g
a rd
e n
B u
ilt u
p P
a d
d y
f ie
ld U
p la
n d
T e
a p
la n
ta tio
n B
a re
la n
d G
ra s
s W
a te
r C
lo u
d S
h a
d o
w
-6.00 -4.00
-2.00 0.00
2.00 4.00
6.00
1994-1997
C h
a n
g e
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
Fo re
s t
B u
s h
M ix
g a
rd e
n B
u ilt
u p
P a
d d
y f
ie ld
U p
la n
d T
e a
p la
n ta
ti o
n Ba
re la
n d
G ra
ss W
a te
r C
lo u
d Sh
a d
o w
-3.00 -2.00
-1.00 0.00
1.00 2.00
3.00 4.00
5.00
1997-2001 C
h a
n g
e
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
F o
re st
B u
sh
Mi xg
a rd
e n
B u
ilt u
p P
a d
d y
fi e
ld
U p
la n
d Te
a p
la n
ta ti
o n
B a
re la
n d
G ra
s s
W a
te r
C lo
u d
S h
a d
o w
-6.00 -4.00
-2.00 0.00
2.00 4.00
6.00
1997-2004
C h
a n
g e
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
F o
re st
B u
sh
M ix
g a
rd e
n
B u
ilt u
p P
a d
d y
fi e
ld U
p la
n d
T e
a p
la n
ta ti
o n
B a
re la
n d
G ra
ss W
a te
r C
lo u
d S
h a
d o
w
-6.00 -4.00
-2.00 0.00
2.00 4.00
6.00
2004-2006
C h
a n
g e
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
Figure 4.4. The rates of land cover conversion from 1991 until 2006 Based on result of classification, forest, bush, upland and bare land has decreased
between 1991 and 1994. However, upland and bare land fluctuate in next year. Its fluctuating happened depends on a season and planting time. Decreasing forest cover
happened consistently until 2006, opposite with increasing in built up settlement cover.
23
0.00 500.00
1000.00 1500.00
2000.00 2500.00
3000.00 3500.00
1991 1994
1997 2001
2004 2006
Year A
re a
he c
ta re
Forest Bush
Mixgarden Builtup
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
0.0 500.0
1000.0 1500.0
2000.0 2500.0
3000.0 3500.0
1991 1994
1997 2001
2004 2006
A re
a he
c ta
re
0.0 200.0
400.0 600.0
800.0 1000.0
1200.0
Year
A re
a he
c ta
re
Forest Builtup
0.0 200.0
400.0 600.0
800.0 1000.0
1200.0 1400.0
1600.0 1800.0
1991 1994
1997 2001
2004 2006
A re
a he
c ta
re
0.0 100.0
200.0 300.0
400.0 500.0
600.0 700.0
800.0 900.0
Year
A re
a he
c ta
re
Bush Mixgarden
Paddy field Upland
Tea plantation Bareland
Grass Water
Cloud Shadow
Figure 4.5. Land conversion processes from 1991 until 2006
Figure 4.5. shows land conversion processes between 1991 and 2006 with all
lands grouped in three clusters. Degradation of ecologically valuable land caused by forest cover decreasing between 1991 until 2006 affects more than 13.66 of the total
land area over 1.315 ha. Moreover, 9.61 of the built upsettlement over 925 ha and 9.48 of cultivated land always in fluctuated depends on a seasons and planting time
over 912 ha. Between 1991 until 2006, bush, mix garden, built up, paddy field, tea plantation,
and grass increased per year by 0.24 , 0.17 , 0.64 , 0.02 , 0.13 and 0.01 , respectively. Forest cover decreased by 1,315 ha representing decrease of 0.91 per
1 2
3
24
year. Areas of upland and bare land also decreased between 1991 until 2006 by 0.17 and 0.13 per year, respectively.
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
2006
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
2004
1991 1994
1997 2001
2004 2006
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
Upper Ciliwung Cibeet
Cigundul Telaga Warna
Nature Reserve Telaga Warna Lake
25
0.00 100.00
200.00 300.00
400.00 500.00
600.00 700.00
800.00 900.00
1000.00
1991 1994
1997 2001
2004 2006
Year A
re a
he c
ta re
0.00 20.00
40.00 60.00
80.00 100.00
120.00 140.00
160.00 180.00
A re
a he
c ta
re
Figure 4.6. Distributions of Land cover from 1991 until 2006 Figure 4.5. and 4.6. suggests that ecological causes behind almost 25 forest
and built up cover conversion of the total area. At the same time, although in fluctuating rate, but cultivated lands for agricultural productions tend to increase. These results
suggest that prospects for land preservation of upper Ciliwung, Cigundul and Cibeet catchments area not very good without changes in policy. However, land preservation of
area Telaga Warna Nature Reserve is currently good.
Figure 4.7. shows that catchments area in upper Ciliwung, Cigundul and Cibeet
has different trend of forest and built upsettlement cover changes. Forest cover of upper Ciliwung watershed has curve decrease stepper than Cigundul and Cibeet watershed.
During 5 years, built up cover in upper Cigundul watershed increased significantly.
Figure 4.7. Trend of forest and built up cover change in three catchments area Increase of degraded land as product of land cover change during 1991
–2006 will be analyzed hereafter-using soil erosion approach.
Forest change rate Built up change rate
26
IV.4. A
