LANDSLIDE ANALYSIS & SUSCEPTIBILITY MAPPING BY USING GIS IN BAO LOC MOUNTAIN PASS, LAM DONG PROVINCE, VIET NAM
LE THI THU HA, Prof. Dr. Dwikorita Karnawati, M.Sc., Ph.D.
2011 | Tesis | S2 Teknik Geologi-
National way 20, situated in Bao Loc mountain pass, Lam Dong provine, is
one of the most important ways which connects Da Lat city to Ho Chi Minh city,
Viet Nam. Most of the study area covered by weathering zone of extrusive rock
(i.e. Andeiste) of Deo Bao Loc formation which is very susceptibility to landslide
occurrence. Landslide occur frequently in the area and seriously affect local living
conditions, irregularly concentratied in August, September and Octorber when the
total rain precipitation reaches 400mm in one month. Therefore, spatial analysis
of landslide susceptibility in the mountainous regions of the Bao Loc is very
important. Hence, this study focuses at a particular mountainous region of about
10 km along national way 20. The research is aimed to develop landslide
susceptibility mapping at 1/50.000 scale by Geographic Information System (GIS)
with SINMAP method which is consider the susceptible landslide area with the
various degree of susceptible.
Data collection, site investigation and other work were performed to
indentify the condions of geomorphology and geology, contributing to landslide
occurrences in the area. To develop landslide susceptibility map by SINMAP
model, some input parameters were selected and prepared such as topography
slope, specific catchment area, geological parameter (soil cohesion, root cohesion,
friction angle, soil depth..), hydrological parameter (rainfall). The topography
slope and specific catchment area are autormatically computed from digital
elevation model (DEM) are. The other input parameters are recognized to be
uncertain so are specified to SINMAP in terms of upper and lower boundaries. In
the study area, two calibration regions which are the weathering zone on extrusive
rock (i.e. andesite) and weathering zone on intrusive rock (i.e. granite) were
chosen on the basic of rock type. Two main analysis scenarios which have
maximum rainfall (17,2mm/day) and minimum rainfall (11,4mm/day) are applied
to analysis stability index.
The results were classified into six stability index classes. There are: stable
(SI>1,5), moderately stable (<1,25
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