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Figure 5.8 Buper Watershed Slope
5.3 Landuse Change Analysis.
Land use change analysis used to comprehend the area changing trends that occurrs in Buper Watershed. Land use change analysis is carried out by identifiying area change in
study site annualy. Data are obtained from land cover map and Google Earth. The land cover map is acquired or downloaded from related agency.
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Through Global Mapper 12 operation and ArcView 3.3, land cover map in 2000 and 2005 are obtained for a data input in land use change analysis, land use suitability, and
further analysis. Through ArcView 3.3 operation on the land cover map 2000 and 2005, in general
Buper watershed land cover are primary-secondary forest and savannah. In land cover 2000, the primary- secondary forest is 7,39 km
2
wide, while the savannah area is 5,21 km
2
, which means that 58,7 of Buper Watershed is forest. In 2005 landcover, primary-
secondary forest is 7,8 km
2
, while the savannah is 4,8 km
2
, which means that 61,9 of Buper Watershed is forest. Land cover of Buper watershed generally dominated by forest
during 2000-2005 and its broadness has been increasing about 3,2 in five years. The 2009 and 2010 land cover as one part of land use analysis was obtained from
Google Earth combined with ArcView 3.3 to make a land cover map and data base 2010. It was done by exporting watershed boundary from SHP format to kmz format using Global
Mapper 12 so that it could be used in Google Earth. To give an accurate result, it was evaluated with study site condition through observatory documentation according to the
position or coordinate of Google Earth and field observation. Based on the application, the result emerge on Buper watershed land cover in 2009 and 2010 shows forest 7,78 km
2
and savannah 4,73 km
2
. Based on the application, a result emerge on Buper watershed land cover in 2009 and 2010 shows forest 7,8 km
2
and savannah 4,8 km
2
.
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Figure 5.9 Buper Land Cover 2000 and Buper Land Cover 2005
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Forest
Savanna
Figure 5.10 Buper Watershed Map and Field Condition 2010 Syncronized
Savanna Forest
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According to land cover maps that has been made, the conclusion that can be taken is land use change in Buper Watershed is slow. In general, land cover can be classified into
primary-secondary forest and savannah. Here are the land cover change in year 2000, 2005, 2009, and 2010 :
Table 5-2 Land Use Change Land Cover
Year 2000 2005 2009 2010
Primary and Secondary Forest km
2
7,39 7,84
7,78 7,79
Savanah km
2
5,21 4,86
4,73 4,82
Average land cover change to Buper Watershed is 0,04 km
2
year. Primary and secondary forest has been expanding to 0,04 km
2
year, while the savannah has been shrinking to 0,04 km
2
year.
Figure 5.11 Forest Cover 2005-2010
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The forest expansion has a pattern following stream where sediments are consentrated. The change to land cover can be seen on Figure 5.15 :
Figure 5.12 Land Cover 2000-2010
The expansion of exposed surface area and the expansion of sedimentation area related closely to erosion rate. The area and the rate of erosion on Buper Watershed will be
studied further in soil erosion analysis.
5.4 Geological Analysis
Kategori