39
Figure 4.4 a Land Cover map of 2009 and b Coverage of each land covers class.
The increasing population density makes the local peoples to expand their settlement and also the agricultural area as their main livelihood. The agricultural
land is not only on the lowland but has stepped into the mountain. If the rate of changes is steady or probably will be faster in the future, it may lead to higher
level of deforestation.
4.1.2 Summary of Land Cover Maps
The land cover maps on Palu Catchment were generated from three different satellite imageries; 1990, 2001, and 2009 respectively trough image
classification processes. The statistics of each land cover class for each land cover period can be summarized as below:
Table 4.1 Summary of land cover maps on 1990, 2001, and 2009
CLASS
1990 2001
2009
km
2
km
2
km
2
CL. 1 Agricultural Land
326.89 10.7
466.1 15.3
806.04 26.4
CL. 2 Barren Land 47.64
1.6 49.57
1.6 49.89
1.6 CL. 3 Build Up area
43.05 1.4
51.17 1.7
58.93 1.9
CL. 4 Forest 2174.72
71.3 2044.13
67.0 1793.19
58.8 CL. 5 Shrub Land
413.63 13.6
394.58 12.9
296.79 9.7
CL. 6 Water Body 44.92
1.5 45.09
1.5 45.41
1.5
Figure 4.5 Increased and decreased of each land cover class
500 1000
1500 2000
2500
1990 2001
2009
CL. 1 Agricultural Land
CL. 2 Barren Land CL. 3 Build Up area
CL. 4 Forest
40
Table 4.2 Summary of land cover changes in Palu Catchment between period of 1990-2001 and 2001-2009.
CLASS 1990-2001
2001-2009 CL. 1 Agricultural Land
139.21 339.94
CL. 2 Barren Land
1.93 0.32
CL. 3 Build Up area
8.12 7.76
CL. 4 Forest
‐130.59 ‐250.94
CL. 5 Shrub Land
‐19.05 ‐97.79
CL. 6 Water Body
0.17 0.32
4.1.3 Change Detection
Statistical analyze was used to assess the land cover changes between 1990-2009 periods. It aimed to identify the changes in probability distribution of
land cover classes whether it has changed or unchanged within given time period. An 30 x 30 meters of Landsat images were used for the change detection process.
Three multi temporal satellite imagery producing two change statistics reports, first for changes between 1990 to 2001 and the last for changes on period of 2001
to 2009. It presents the changes of land covers in Palu catchment in last 20 years. Table 4.3 – 4.4 presents the changes of land cover class to another class. The
unchanged classes are shows on the major diagonal of these matrixes. Table 4.3 Change detection statistics report on 1990 – 2001 in km
2
CLASS CL. 1
AG CL. 2
BL CL. 3
BU CL. 4 F
CL. 5 SL
CL. 6 W
Total 1990
CL. 1 Agricultural Land 310.46
0.00 1.54
1.54 9.76
3.60 326.91
CL. 2 Barren Land 0.11
47.18 0.23
0.00 0.00
0.13 47.65
CL. 3 Build Up area 0.00
0.00 42.82
0.00 0.00
0.0 42.82
CL. 4 Forest 23.96
0.00 0.14
2,040.78 109.66
0.37 2174.91
CL. 5 Shrub Land 127.31
2.41 6.36
1.22 273.92
1.77 412.99
CL. 6 Water Body 4.26
0.00 0.10
0.13 1.15
39.26 44.90
Total 2001 466.11
49.59 51.18
2,043.66 394.51
45.35 3,050.16
Table 4.4 Change detection statistics report on 2001 – 2009 in km
2
CLASS CL. 1
AG CL. 2
BL CL. 3
BU CL. 4 F
CL. 5 SL
CL. 6 W
Total 2001
CL. 1 Agricultural Land 450.02
0.00 4.16
0.63 7.50
3.80 466.11
CL. 2 Barren Land 0.00
49.33 0.10
0.16 0.00
0.00 49.59
CL. 3 Build Up area 0.0
0.00 50.84
0.00 0.00
0.00 50.84
CL. 4 Forest 169.55
0.58 0.14
1,791.68 81.09
0.76 2043.8
CL. 5 Shrub Land 181.86
0.00 3.39
0.55 207.52
1.38 394.7
CL. 6 Water Body 4.67
0.00 0.28
0.19 0.57
39.43 45.14
Total 2009 806.10
49.91 58.91
1,793.21 296.68
45.38 3,050.16
