The climate type of the area is tropical monsoon, hot and humid throughout the year maximum temperature ranging from 29
o
C - 32
o
C, minimum temperature from 21
o
C - 22
o
C and humidity around 84 - 89. The wet months over 200 mm rainfall per month occur during November – April and average driest month
is August less than 100 mm rainfall per month. Average annual rainfall is about 2.400 mm. According to the Oldeman classification, the agro climate is C-1, with
the 5 to 6 wet months rainfall over 200 mm and 0-1 dry months rainfall less than 100 mm. The climate and rainfall type supports a range of crops.
The macro topography is generally flat or gently sloping towards natural drainage outlets. At micro level, the topography is very irregular and disturbed as
a result of reclamation activities, e.g. the subsidence of mineral soils and the oxidation of peat. Human activities such as leveling and construction of sorjans
further contributed to the disturbance of the original topography.
3.2 Data Preparation
3.2.1 Data Acquisition
The remotely sensed data used in this research are a Image acquisition on 15 April 2000 +ETM image path 124, row 62 acquired on 15 April 2000 and a
Image acquisition on 16 May 2006 TM path 124, row 62 acquired on 16 May 2006. The data is obtained from the United States Geological Survey USGS
website. The area of interest of image acquisition on 15 April 2000 can be seen in Figure 5 and for image acquisition on 16 may 2006 can be seen in Figure 6.
Other data used in the research were Swamps Distribution Map acquired in 2009 from Public Work Office of Banyuasin Regency, Rupa Bumi Indonesia
acquired on 2003 from National Coordination Agency for Surveys and Mapping, Land System Map acquired on 1989 from Indonesian Center for Agricultural
Land Resources Research and Development, Ministry of Agriculture. Ground data obtained from ground truth using GPS Garmin was done in the
Delta Upang, Delta Telang I and Muara Sugihan.
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3.2.2. Image Data Pre-Processing
The study area was a subset from full scene image acquisition on 15 April 2000 and image acquisition on 16 May 2006. Some pre-processing was done for
each image before to do the swamps analysis. The pre-processing image included:
A. Geometric Correction
Raw digital images usually contain geometric distortions; it cannot be used as maps. Geometric correction is needed because usually the raw digital
image contains geometric distortions caused by variation in the surface ground curve, altitude, attitude of sensor platform, etc. The intent of geometric
correction is to compensate the distortions introduced by these factors so that the corrected image will have the geometric integrity of a map.
Geometric correction was done using digital map as reference and done by :
1. Collection of GCPs. These are defined as points that are clearly
identifiable on both the satellite imagery and reference image vector data. The GCPs should be widely distributed and the RMS error not
more than 0,5. In this research, Landsat imagery was registered using topographic map scale 1:50,000. In selecting the GCPs, one has to
be careful, not only one should check that the object selected on the two images is one and the same, but one also has to be sure that the
two have the same location on each image. 2.
Rectification : Rectify data set using Polynomial Control Point. 3.
Resampling : Using Nearest Neighbor Resampling.
B. Radiometric Correction
The effect of atmospheric scattering caused by water molecules is a problem in imagery that should be eliminated or minimized to avoid bias
for each spectral band. Histogram or atmospheric adjustment is one of the ways to minimize this bias.
C. Image Cropping
Image cropping was done in order to extract the study area, because the original image covers a large area, while the study is only part of that
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image. Cropping the image is needed because the study area is limited only in centre of swamps reclamation area.
Figure 5 Landsat 7 imagery acquisition on 15 April 2000
Figure 6 Landsat 5 imagery acquisition on 16 May 2006
3.2.3 Vector Data Pre-Processing
Most the data for suitability analysis were secondary data, which included in Land System Data. The data were peat depth, pH, salinity and slope map. That
map represents features being necessary to GIS process.
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3.3 Framework of Research
The frame work for this research included swamps identification procedures and land suitability analysis. General framework for this research can be seen in
Figure 7. It is combination of Remote Sensing and Geographic Information System. The research has been done under two phases as follows:
• Swamps Identification. This section was done by using satellite imagery analysis based on the different characteristic between 2 satellite imagery with
different season acquisition. Referring to the archive image availability, image acquisition on 15 April 2000 is used as the image in wet season and
image acquisition on 16 May 2006 is used as the image in dry season. The framework of this section can be shown in Figure 9.
• Land Suitability Analysis. This section was done by using spatial data to produce the suitability classes for the swamps area that resulted from the
difference area between 2 satellite imagery results after some processing from previous phase.
General flowchart for this research can be seen in Figure 7.
Figure 7 General flowchart for the research
3.3.1 Swamps Identification
Swamps identification was done by calculating and analyzing 3 parameters that are:
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