In many country and also in Indonesia, a recent imaginative development is the use of computers to calculate and draw predictive hazard maps. Once the
controling parameters of the hazard are known these can be combined into mathematical form and programmed once and for all.
The differences between this research compared with another that mentioned above, principally in geological and geomorphological interpretation
point of view. This research thoroughly used GIS and Remote Sensing Technology for determining geological hazard sensitive area through integrating
remote sensing capability especially principal component analysis PCA procedures to obtain common picture of present rocks and minerals distribution
which indicating past as well as endogenetic and exogenetic processes.
2.5. Geology of Research Area
Research area located in West Java, precisely one scene of Landsat 7 ETM, path: 122 row: 65. Figure 2.8
Figure 2.8. Research area Landsat TM PathRow: 12265
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In general, geologically, there are three physiographic zone that represent sensitive areas in Southern West Java, that are Bogor Zone, Southern Mountain
Range Zone ‘Zona Pegunungan Selatan’ and range of hill in Bandung Zone.
Ra n ge of h ill in Ba n du n g Zon e
Pa da la r a n g Sou t h e r n M ou n t a in s Zon e
Ga r u t Se la t a n , Cia n j u r , Su k a bu m i, Pe la bu h a n Ra t u
Bogor Zon e Su ba n g, Cia m is, Su m e da n g
Physiographic Zone Training Area
Table 2.1. Study area of Research
Figure 2.9. Physiographic Distribution Map of West Java Asikin, 1986
According to Sampurno 1975, Bogor Zone is characterized by series of Tertiary marine deposite which mostly consist of clay, napal, tuff claystone,
sandstone and volcanic sediment. Most of those sedimentary beds folded moderately with steepness more than 25 degree. Dimensional of this area more or
less 10 percent of West Java. Covered unconformability by young volcanic sediment which characterized incoherent to crumbel, porous and permeable.
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Fault structures frequently founded with intensive joint. Field frequently constitute elongated hilliest that unidirectional with strike of bed that shows
West-East direction with steepness of slope about 10 - 30 percent in general including steepy escarpment. Loose rock particles deposit can be founded at base
of escarpments as there are in North Ciamis area. Furthermore, the Southern Mountain Range Zone, geologically
characterized by Tertiary marine sedimentary rocks in term of clay, sandstone, limestone and turbidity volcanic sediment. Additionally, igneous rock intrusion
also exist in this zone. According to Sampurno 1975, in general, this zone has a horizontal or aslant beds direct to South. Dimesional of this area more or less 20
percent of West Java and in general constitute form of plateau with steepy valley incised. Loose rock particles deposit founded at broad valley basement which
represent accumulated from valleys wall surrounding as there are in South Garut and South Cianjur.
Endmost, the Range of Hill in Bandung Zone, According to Sampurno 1975, this area deputized by Rajamandala Mountains which geologically
characterized by Tertiary marine sedimentary rocks in term of clay, sandstone, limestone, with small intrusion on some place. Steepness of slope is about 25 - 45
degree which controlled by fault and intensive joint. The area, in general approximately steepy in term of elongated hilliest with steepy escarpments.
Tectonically, physiographically Banten area very resemble with characteristic of Sumatra Island, if compared with its East side. Except some
similarity of its morphological forms, its also with existence of volcanism product
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which many acid tuff Banten Tuff as does Acid Lampung Tuff, at least it can be used as a base of an opinion.
Figure 2.10. Active Tectronic of Indonesia: Crustal motion from GPS study. Natawijaya Latif 2006
According to Asikin 1986 based on gravity, seismic, landsat image interpretation and field observation, there are four fault pattern systems in West
Java, i.e.: 1. Sumatra direction Northwest - Southeast,
2. Java direction East - West, and 3. North - South direction which very dominant at North side of Java Island and
Java Sea area. 4. Southwest - Northeast direction that very prominent at corner of Northeast of
Java Island Cimandiri Sukabumi which assumed still active in connection with distribution of intermediate and shallow earthquake epicentre. Figure
2.11. 25
Figure 2.11. Southeast Asia Seismic Zonation Map Planned by USGS USGS in Irsyam, 2006
The oldest rock unit that exsposed in West Java is Early Eocene rocks at Ciletuh area Southern Pelabuhan Ratu. Its tectonically connected with
brecciated and serpentinized ophiolites rock at contact belt. Those ophiolites interpreted as part of melangé which also constitute of Early Eocene olistostrome.
Thus, the oldest rock unit in West Java is Pre-Eocene subduction belt. Another Pre-Tertiary rocks in West Java only founded from oil drilling at
North in the form of granitic igneous rock, andesitic volcanic rock association
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such volcanic breccia, lava and tuff Jatibarang Formation, and also metamorphic rocks such slate, phyllite and marble. Those rocks association mentioned can be
related with Cretaceous subduction belt that in this case constitute its magmatic belt.
Another tectonic setting of West Java according to Asikin 1986 is Tertiary Magmatic Belt which located along Southern Java Island coast line namely Old
Andesite Formation at the age of Early Oligo Miocene. In West Java, part of this formation called as Jampang Formation.
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III. METHODOLOGY
3.1 Time and Location
This research has been conducted from January 2006 to May 2006 at MIT Master of Science in Information Technology research laboratory, SEAMEO
BIOTROP, Bogor Agricultural University, Bogor and GTCUNPAK UNPAK GIS Center, Faculty of Engineering, Universitas Pakuan, Bogor. The location of
this research is in Southern West Java Figure 2.8. Page: 22 where active tectonic produces many geological phenomena which generated hazard sensitive areas.
3.2 Research Area
The research is focus on the determination toward sensitive area based on geological hazard perspectives by means of remotely sensed data and GIS spatial
analysis methods, and also it will extend the mitigation recommendation for secure settlement location by means weighting procedures for decision making.
3.3 Data Sources
Mainly the data has been used for this research acquired from previous geologic research report, Administration Map from BAKOSURTANAL Figure
3.1, free downloaded SRTM-Shuttle Radar Topographic Mission Figure 3.2 from internet, Geologic digital map from PT. Aneka Tambang, Tbk - Geomineral
Unit, Jakarta Figure 3.3 and Landsat TM image of West Java 2001 with pathrow = 12265 Figure 3.4.
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