The hazard map was developed with 0.5m
spatial resolution that combines different
types of landslide. Based on the landslide
inventory map in the study area, the landslide
hazard map was developed using data on the
majority rotational/translational landslides
(61%), followed by rockfall (18%) and debris flow
(15%). Based on this information, the landslide
hazard map can be used for vulnerability and
risk assessments, which rely on the fact that
the selected areas only contain rotational and
translational landslides. The landslide hazard
maps have been classified onto five classes
namely very low, low, medium, high and very
high hazard (Figure 3.5 and Figure 3.6). Based
on the map, the worst-case landslide hazard
class is assigned for each polygon of CI.
BUILDING AT RINGLET NO. OF BUILDINGS
Total Building 334
Hazard
Building at Hazard (Low)
Building at Hazard (Medium)
Building at Hazard (High)
Building at Hazard (Very High)
12
81
164
77
Vulnerability
Building at Vulnerability (Moderate)
Building at Vulnerability (High)
332
2
Risk
Building at Risk (Medium)
Building at Risk (High)
91
243
Table 3.2: Statistics of buildings from Hazard,
Vulnerability and Risk maps at Ringlet.
Vulnerability and Risk Index for the Entire CI
The landslide vulnerability map produced for
buildings at Ringlet (Figure 3.7) shows that most
of the buildings were categorised in the Moderate
class. There were however, two buildings (from
a total of 334) that were categorised in the High
Vulnerability class (Table 3.2). For the landslide
risk map, among all the building in this area, 91
were categorised as Medium risk while the rests
(243 buildings) were identified as High risk.
For the map of landslide vulnerability of roads
at Lembah Bertam, the analysis produced only
two types of classes: Moderate and High classes.
Among these, most of the roads here were
categorised as Moderate and only a small number
of roads were rated as High Vulnerability (Figure
3.9). One possible explanation for this might be
that most of the roads here are located outside
or away from the landslide polygons at Lembah
Bertam. Roads that have been categorised as
having High Vulnerability were most likely located
inside landslide polygons that might have a high
hazard as well. The risk map of the roads in
this area produced three types of risk classes:
Medium, High and Very High. The roads in the flat
area (i.e. centre of study area) were categorised as
Medium Risk and the same roads that had High
Vulnerability appeared to be categorised as Very
High Level of risk. Details of road length from each
class for Hazard, Vulnerability and Risk maps can
be found in Table 3.2.
For the vulnerability of roads in Ringlet (Figure
3.10), similar comments can be made showing
the Moderate class dominated this area. However,
there were three types of vulnerability classes
which also include Low and High Vulnerability,
apart from Moderate classes. There were only a
few roads that were categorised in the Low and
High classes. For example, the roads that were
categorised as High Vulnerability were located in
the northern region of the study area. For the risk
map of the roads in this area (Figure 3.11), four
classes were produced; Low, Medium, High and
Very High. Most of the roads were categorised as
having High Risk, followed by Medium Risk and
Low Risk, with Very High Risk appeared to be the
lowest among all (i.e. only 816in length from a
total of 40,619m road length) (Table 3.3).
For the vulnerability of the TNB Powerline at
Ringlet, only five pylon units were available and
analysed in this study (all located at the southern
region of study area). Among these five, all of
them were categorised in the Moderate class of
vulnerability (Figure 3.13). As for risk, all these five
units were categorised as having High Risk (Figure
3.14). For the TNB powerline in Lembah Bertam,
there were nine pylon units, and the results
indicate that eight of them were categorised in
the Moderate class of vulnerability and only one
unit as High Vulnerability (Figure 3.15). For the
risk, all the nine pylon units in this study area were
categorised as having High Risk (Figure 3.16).
59