Ingenieur Vol 80 ingenieur 2019 octoberfinal | Page 59

Likelihood (hazard) Consequences to property (Vulnerability) Very High High Medium Low Very Low Very High VH VH H H M High VH H H M L-M Medium H H M L-M VL-L Low M-H M L-M VL-L VL Very Low M-L LM VL-L VL VL Legend: VH H = = Very high risk High risk M = Moderate risk L = Low risk VL = Very low risk Table 3.1: Improvised International Standard Risk Assessment Matrix landslide cases (Corangamite Catchment Management Authority, 2012). • To use when information related to quantitative landslide risk assessment is absent (Pellicani et al., 2017). results of the simulated building and residential landslide vulnerabilities for best, medium and worst case scenarios. The best case scenarios produced a vulnerability value of 0.21, i.e. “low vulnerability” class. The medium case scenarios successfully produced vulnerability values of 0.50 that fall into “medium vulnerability” class. The worst-case scenario successfully achieved “very high vulnerability” class with a value of 0.93. Based on the results, we conclude that the indicators and sub-indicators have been well defined and the weight values have a good distribution as shown from the vulnerability value. Landslide Inventory Map Based on the basic principles and methods of landslide identification and detection described above, the resulted landslide inventory map for Ringlet and Lembah Bertam areas are shown in Figure 3.3 and Figure 3.4, respectively. In these maps, the identified landslides are delineated by red polygons. It is important to note that in this study, although field verifications were not conducted, the landslide inventory maps were produced by an expert with many years of experience in landslide identification and interpretation. Focus Group Discussions of Key Findings Landslide Hazard Map The Focus Group Discussions (FGDs) identified important key challenges and best practices in implementing the landslide vulnerability and determination of the risk index for critical infrastructures, as well as recommended ways to improve implementation going forward. More FGDs were held to ensure that all weights given are relevant. Case Scenarios In this experiment, the best case scenarios were expected to produce the lowest vulnerability value and be classified in the “very low vulnerability” class. On the other hand, the medium case scenarios were expected to show the estimated vulnerability values to be classified in the “medium vulnerability” class. Finally, the worst case scenarios were expected to produce the highest vulnerability value that can be classified as “very high vulnerability” class. Figure 3.1 describes the Landslide vulnerability and risk maps require a hazard map to be generated at a specific level of detail and quality. For example, vulnerability assessment methods developed for different types of landslides may require landslide hazard maps to be generated for different landslide types in the same spatial scale. In addition, each landslide type should be accompanied by detailed information e.g. depth of landslide, run out area, velocity etc. This information is required to combine the landslide hazard map and vulnerability map for landslide risk production. In this study, the landslide hazard map was obtained from the Department of Mineral and Geoscience of Malaysia (JMG). The use of JMG’s landslide hazard maps is governed by JMG’s practices, therefore the consultant does not have any control over how the hazard map was produced. However, due to the ultimate aim of this project to produce guidelines rather than a technical report, this was acceptable. 57